Merge pull request #183 from fatedier/fatedier/udp

support udp type

.travis.yml

@@ -3,8 +3,8 @@ language: go
 
 go:
     - 1.5.4
-    - 1.6.3
-    - 1.7
+    - 1.6.4
+    - 1.7.4
 
 install:
     - make

Godeps/Godeps.json

@@ -1,9 +1,9 @@
 {
 	"ImportPath": "github.com/fatedier/frp",
-	"GoVersion": "go1.6",
-	"GodepVersion": "v74",
+	"GoVersion": "go1.7",
+	"GodepVersion": "v75",
 	"Packages": [
-		"./src/..."
+		"./..."
 	],
 	"Deps": [
 		{
@@ -11,16 +11,31 @@
 			"Comment": "v1.7.0-7-gefbde1e",
 			"Rev": "efbde1ee77517486eac03e814e01d724ddad18e6"
 		},
+		{
+			"ImportPath": "github.com/davecgh/go-spew/spew",
+			"Comment": "v1.1.0",
+			"Rev": "346938d642f2ec3594ed81d874461961cd0faa76"
+		},
 		{
 			"ImportPath": "github.com/docopt/docopt-go",
 			"Comment": "0.6.2",
 			"Rev": "784ddc588536785e7299f7272f39101f7faccc3f"
 		},
+		{
+			"ImportPath": "github.com/pmezard/go-difflib/difflib",
+			"Comment": "v1.0.0",
+			"Rev": "792786c7400a136282c1664665ae0a8db921c6c2"
+		},
 		{
 			"ImportPath": "github.com/rakyll/statik/fs",
 			"Comment": "v0.1.0",
 			"Rev": "274df120e9065bdd08eb1120e0375e3dc1ae8465"
 		},
+		{
+			"ImportPath": "github.com/stretchr/testify/assert",
+			"Comment": "v1.1.4-25-g2402e8e",
+			"Rev": "2402e8e7a02fc811447d11f881aa9746cdc57983"
+		},
 		{
 			"ImportPath": "github.com/vaughan0/go-ini",
 			"Rev": "a98ad7ee00ec53921f08832bc06ecf7fd600e6a1"

conf/frpc.ini

@@ -29,6 +29,11 @@ use_gzip = false
 # connections will be established in advance, default value is zero
 pool_count = 10
 
+[dns]
+type = udp
+local_ip = 114.114.114.114
+local_port = 53
+
 # Resolve your domain names to [server_addr] so you can use http://web01.yourdomain.com to browse web01 and http://web02.yourdomain.com to browse web02, the domains are set in frps.ini
 [web01]
 type = http

conf/frps.ini

@@ -39,6 +39,12 @@ auth_token = 123
 bind_addr = 0.0.0.0
 listen_port = 6000
 
+[dns]
+type = udp
+auth_token = 123
+bind_addr = 0.0.0.0
+listen_port = 5353
+
 [web01]
 # if type equals http, vhost_http_port must be set
 type = http

src/cmd/frpc/control.go

@@ -120,7 +120,7 @@ func msgSender(cli *client.ProxyClient, c *conn.Conn, msgSendChan chan interface
 		}
 
 		buf, _ := json.Marshal(msg)
-		err := c.Write(string(buf) + "\n")
+		err := c.WriteString(string(buf) + "\n")
 		if err != nil {
 			log.Warn("ProxyName [%s], write to server error, proxy exit", cli.Name)
 			c.Close()
@@ -166,7 +166,7 @@ func loginToServer(cli *client.ProxyClient) (c *conn.Conn, err error) {
 	}
 
 	buf, _ := json.Marshal(req)
-	err = c.Write(string(buf) + "\n")
+	err = c.WriteString(string(buf) + "\n")
 	if err != nil {
 		log.Error("ProxyName [%s], write to server error, %v", cli.Name, err)
 		return
@@ -191,6 +191,12 @@ func loginToServer(cli *client.ProxyClient) (c *conn.Conn, err error) {
 	}
 
 	log.Info("ProxyName [%s], connect to server [%s:%d] success!", cli.Name, client.ServerAddr, client.ServerPort)
+
+	if cli.Type == "udp" {
+		// we only need one udp work connection
+		// all udp messages will be forwarded throngh this connection
+		go cli.StartUdpTunnelOnce(client.ServerAddr, client.ServerPort)
+	}
 	return
 }
 

src/cmd/frps/control.go

@@ -72,14 +72,14 @@ func controlWorker(c *conn.Conn) {
 	// login when type is NewCtlConn or NewWorkConn
 	ret, info := doLogin(cliReq, c)
 	// if login type is NewWorkConn, nothing will be send to frpc
-	if cliReq.Type != consts.NewWorkConn {
+	if cliReq.Type == consts.NewCtlConn {
 		cliRes := &msg.ControlRes{
 			Type: consts.NewCtlConnRes,
 			Code: ret,
 			Msg:  info,
 		}
 		byteBuf, _ := json.Marshal(cliRes)
-		err = c.Write(string(byteBuf) + "\n")
+		err = c.WriteString(string(byteBuf) + "\n")
 		if err != nil {
 			log.Warn("ProxyName [%s], write to client error, proxy exit", cliReq.ProxyName)
 			return
@@ -145,9 +145,11 @@ func msgReader(s *server.ProxyServer, c *conn.Conn, msgSendChan chan interface{}
 		if err != nil {
 			if err == io.EOF {
 				log.Warn("ProxyName [%s], client is dead!", s.Name)
+				s.Close()
 				return err
 			} else if c == nil || c.IsClosed() {
 				log.Warn("ProxyName [%s], client connection is closed", s.Name)
+				s.Close()
 				return err
 			}
 			log.Warn("ProxyName [%s], read error: %v", s.Name, err)
@@ -184,7 +186,7 @@ func msgSender(s *server.ProxyServer, c *conn.Conn, msgSendChan chan interface{}
 		}
 
 		buf, _ := json.Marshal(msg)
-		err := c.Write(string(buf) + "\n")
+		err := c.WriteString(string(buf) + "\n")
 		if err != nil {
 			log.Warn("ProxyName [%s], write to client error, proxy exit", s.Name)
 			s.Close()
@@ -194,6 +196,9 @@ func msgSender(s *server.ProxyServer, c *conn.Conn, msgSendChan chan interface{}
 }
 
 // if success, ret equals 0, otherwise greater than 0
+// NewCtlConn
+// NewWorkConn
+// NewWorkConnUdp
 func doLogin(req *msg.ControlReq, c *conn.Conn) (ret int64, info string) {
 	ret = 1
 	// check if PrivilegeMode is enabled
@@ -334,6 +339,13 @@ func doLogin(req *msg.ControlReq, c *conn.Conn) (ret int64, info string) {
 		}
 		// the connection will close after join over
 		s.RegisterNewWorkConn(c)
+	} else if req.Type == consts.NewWorkConnUdp {
+		// work conn for udp
+		if s.Status != consts.Working {
+			log.Warn("ProxyName [%s], is not working when it gets one new work connnection for udp", req.ProxyName)
+			return
+		}
+		s.RegisterNewWorkConnUdp(c)
 	} else {
 		info = fmt.Sprintf("Unsupport login message type [%d]", req.Type)
 		log.Warn("Unsupport login message type [%d]", req.Type)

src/models/client/client.go

@@ -17,6 +17,7 @@ package client
 import (
 	"encoding/json"
 	"fmt"
+	"sync"
 	"time"
 
 	"github.com/fatedier/frp/src/models/config"
@@ -34,19 +35,71 @@ type ProxyClient struct {
 
 	RemotePort    int64
 	CustomDomains []string
+
+	udpTunnel *conn.Conn
+	once      sync.Once
+}
+
+// if proxy type is udp, keep a tcp connection for transferring udp packages
+func (pc *ProxyClient) StartUdpTunnelOnce(addr string, port int64) {
+	pc.once.Do(func() {
+		var err error
+		var c *conn.Conn
+		udpProcessor := NewUdpProcesser(nil, pc.LocalIp, pc.LocalPort)
+		for {
+			if pc.udpTunnel == nil || pc.udpTunnel.IsClosed() {
+				if HttpProxy == "" {
+					c, err = conn.ConnectServer(fmt.Sprintf("%s:%d", addr, port))
+				} else {
+					c, err = conn.ConnectServerByHttpProxy(HttpProxy, fmt.Sprintf("%s:%d", addr, port))
+				}
+				if err != nil {
+					log.Error("ProxyName [%s], udp tunnel connect to server [%s:%d] error, %v", pc.Name, addr, port, err)
+					time.Sleep(5 * time.Second)
+					continue
+				}
+
+				nowTime := time.Now().Unix()
+				req := &msg.ControlReq{
+					Type:          consts.NewWorkConnUdp,
+					ProxyName:     pc.Name,
+					PrivilegeMode: pc.PrivilegeMode,
+					Timestamp:     nowTime,
+				}
+				if pc.PrivilegeMode == true {
+					req.PrivilegeKey = pcrypto.GetAuthKey(pc.Name + PrivilegeToken + fmt.Sprintf("%d", nowTime))
+				} else {
+					req.AuthKey = pcrypto.GetAuthKey(pc.Name + pc.AuthToken + fmt.Sprintf("%d", nowTime))
+				}
+
+				buf, _ := json.Marshal(req)
+				err = c.WriteString(string(buf) + "\n")
+				if err != nil {
+					log.Error("ProxyName [%s], udp tunnel write to server error, %v", pc.Name, err)
+					c.Close()
+					time.Sleep(1 * time.Second)
+					continue
+				}
+				pc.udpTunnel = c
+				udpProcessor.UpdateTcpConn(pc.udpTunnel)
+				udpProcessor.Run()
+			}
+			time.Sleep(1 * time.Second)
+		}
+	})
 }
 
-func (p *ProxyClient) GetLocalConn() (c *conn.Conn, err error) {
-	c, err = conn.ConnectServer(fmt.Sprintf("%s:%d", p.LocalIp, p.LocalPort))
+func (pc *ProxyClient) GetLocalConn() (c *conn.Conn, err error) {
+	c, err = conn.ConnectServer(fmt.Sprintf("%s:%d", pc.LocalIp, pc.LocalPort))
 	if err != nil {
-		log.Error("ProxyName [%s], connect to local port error, %v", p.Name, err)
+		log.Error("ProxyName [%s], connect to local port error, %v", pc.Name, err)
 	}
 	return
 }
 
-func (p *ProxyClient) GetRemoteConn(addr string, port int64) (c *conn.Conn, err error) {
+func (pc *ProxyClient) GetRemoteConn(addr string, port int64) (c *conn.Conn, err error) {
 	defer func() {
-		if err != nil {
+		if err != nil && c != nil {
 			c.Close()
 		}
 	}()
@@ -57,29 +110,27 @@ func (p *ProxyClient) GetRemoteConn(addr string, port int64) (c *conn.Conn, err
 		c, err = conn.ConnectServerByHttpProxy(HttpProxy, fmt.Sprintf("%s:%d", addr, port))
 	}
 	if err != nil {
-		log.Error("ProxyName [%s], connect to server [%s:%d] error, %v", p.Name, addr, port, err)
+		log.Error("ProxyName [%s], connect to server [%s:%d] error, %v", pc.Name, addr, port, err)
 		return
 	}
 
 	nowTime := time.Now().Unix()
 	req := &msg.ControlReq{
 		Type:          consts.NewWorkConn,
-		ProxyName:     p.Name,
-		PrivilegeMode: p.PrivilegeMode,
+		ProxyName:     pc.Name,
+		PrivilegeMode: pc.PrivilegeMode,
 		Timestamp:     nowTime,
 	}
-	if p.PrivilegeMode == true {
-		privilegeKey := pcrypto.GetAuthKey(p.Name + PrivilegeToken + fmt.Sprintf("%d", nowTime))
-		req.PrivilegeKey = privilegeKey
+	if pc.PrivilegeMode == true {
+		req.PrivilegeKey = pcrypto.GetAuthKey(pc.Name + PrivilegeToken + fmt.Sprintf("%d", nowTime))
 	} else {
-		authKey := pcrypto.GetAuthKey(p.Name + p.AuthToken + fmt.Sprintf("%d", nowTime))
-		req.AuthKey = authKey
+		req.AuthKey = pcrypto.GetAuthKey(pc.Name + pc.AuthToken + fmt.Sprintf("%d", nowTime))
 	}
 
 	buf, _ := json.Marshal(req)
-	err = c.Write(string(buf) + "\n")
+	err = c.WriteString(string(buf) + "\n")
 	if err != nil {
-		log.Error("ProxyName [%s], write to server error, %v", p.Name, err)
+		log.Error("ProxyName [%s], write to server error, %v", pc.Name, err)
 		return
 	}
 
@@ -87,12 +138,12 @@ func (p *ProxyClient) GetRemoteConn(addr string, port int64) (c *conn.Conn, err
 	return
 }
 
-func (p *ProxyClient) StartTunnel(serverAddr string, serverPort int64) (err error) {
-	localConn, err := p.GetLocalConn()
+func (pc *ProxyClient) StartTunnel(serverAddr string, serverPort int64) (err error) {
+	localConn, err := pc.GetLocalConn()
 	if err != nil {
 		return
 	}
-	remoteConn, err := p.GetRemoteConn(serverAddr, serverPort)
+	remoteConn, err := pc.GetRemoteConn(serverAddr, serverPort)
 	if err != nil {
 		return
 	}
@@ -101,7 +152,7 @@ func (p *ProxyClient) StartTunnel(serverAddr string, serverPort int64) (err erro
 	log.Debug("Join two connections, (l[%s] r[%s]) (l[%s] r[%s])", localConn.GetLocalAddr(), localConn.GetRemoteAddr(),
 		remoteConn.GetLocalAddr(), remoteConn.GetRemoteAddr())
 	needRecord := false
-	go msg.JoinMore(localConn, remoteConn, p.BaseConf, needRecord)
+	go msg.JoinMore(localConn, remoteConn, pc.BaseConf, needRecord)
 
 	return nil
 }

src/models/client/config.go

@@ -130,7 +130,7 @@ func LoadConf(confFile string) (err error) {
 			proxyClient.Type = "tcp"
 			tmpStr, ok = section["type"]
 			if ok {
-				if tmpStr != "tcp" && tmpStr != "http" && tmpStr != "https" {
+				if tmpStr != "tcp" && tmpStr != "http" && tmpStr != "https" && tmpStr != "udp" {
 					return fmt.Errorf("Parse conf error: proxy [%s] type error", proxyClient.Name)
 				}
 				proxyClient.Type = tmpStr

src/models/client/process_udp.go

@@ -0,0 +1,153 @@
+// Copyright 2016 fatedier, fatedier@gmail.com
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package client
+
+import (
+	"fmt"
+	"io"
+	"net"
+	"sync"
+	"time"
+
+	"github.com/fatedier/frp/src/models/msg"
+	"github.com/fatedier/frp/src/utils/conn"
+	"github.com/fatedier/frp/src/utils/pool"
+)
+
+type UdpProcesser struct {
+	tcpConn *conn.Conn
+	closeCh chan struct{}
+
+	localAddr string
+
+	// cache local udp connections
+	// key is remoteAddr
+	localUdpConns map[string]*net.UDPConn
+	mutex         sync.RWMutex
+	tcpConnMutex  sync.RWMutex
+}
+
+func NewUdpProcesser(c *conn.Conn, localIp string, localPort int64) *UdpProcesser {
+	return &UdpProcesser{
+		tcpConn:       c,
+		closeCh:       make(chan struct{}),
+		localAddr:     fmt.Sprintf("%s:%d", localIp, localPort),
+		localUdpConns: make(map[string]*net.UDPConn),
+	}
+}
+
+func (up *UdpProcesser) UpdateTcpConn(c *conn.Conn) {
+	up.tcpConnMutex.Lock()
+	defer up.tcpConnMutex.Unlock()
+	up.tcpConn = c
+}
+
+func (up *UdpProcesser) Run() {
+	go up.ReadLoop()
+}
+
+func (up *UdpProcesser) ReadLoop() {
+	var (
+		buf string
+		err error
+	)
+	for {
+		udpPacket := &msg.UdpPacket{}
+
+		// read udp package from frps
+		buf, err = up.tcpConn.ReadLine()
+		if err != nil {
+			if err == io.EOF {
+				return
+			} else {
+				continue
+			}
+		}
+		err = udpPacket.UnPack([]byte(buf))
+		if err != nil {
+			continue
+		}
+
+		// write to local udp port
+		sendConn, ok := up.GetUdpConn(udpPacket.SrcStr)
+		if !ok {
+			dstAddr, err := net.ResolveUDPAddr("udp", up.localAddr)
+			if err != nil {
+				continue
+			}
+			sendConn, err = net.DialUDP("udp", nil, dstAddr)
+			if err != nil {
+				continue
+			}
+
+			up.SetUdpConn(udpPacket.SrcStr, sendConn)
+		}
+
+		_, err = sendConn.Write(udpPacket.Content)
+		if err != nil {
+			sendConn.Close()
+			continue
+		}
+
+		if !ok {
+			go up.Forward(udpPacket, sendConn)
+		}
+	}
+}
+
+func (up *UdpProcesser) Forward(udpPacket *msg.UdpPacket, singleConn *net.UDPConn) {
+	addr := udpPacket.SrcStr
+	defer up.RemoveUdpConn(addr)
+
+	buf := pool.GetBuf(2048)
+	for {
+		singleConn.SetReadDeadline(time.Now().Add(120 * time.Second))
+		n, remoteAddr, err := singleConn.ReadFromUDP(buf)
+		if err != nil {
+			return
+		}
+
+		// forward to frps
+		forwardPacket := msg.NewUdpPacket(buf[0:n], remoteAddr, udpPacket.Src)
+		up.tcpConnMutex.RLock()
+		err = up.tcpConn.WriteString(string(forwardPacket.Pack()) + "\n")
+		up.tcpConnMutex.RUnlock()
+		if err != nil {
+			return
+		}
+	}
+}
+
+func (up *UdpProcesser) GetUdpConn(addr string) (singleConn *net.UDPConn, ok bool) {
+	up.mutex.RLock()
+	defer up.mutex.RUnlock()
+	singleConn, ok = up.localUdpConns[addr]
+	return
+}
+
+func (up *UdpProcesser) SetUdpConn(addr string, conn *net.UDPConn) {
+	up.mutex.Lock()
+	defer up.mutex.Unlock()
+	up.localUdpConns[addr] = conn
+}
+
+func (up *UdpProcesser) RemoveUdpConn(addr string) {
+	up.mutex.Lock()
+	defer up.mutex.Unlock()
+	if c, ok := up.localUdpConns[addr]; ok {
+		c.Close()
+	}
+	delete(up.localUdpConns, addr)
+}

src/models/consts/consts.go

@@ -37,4 +37,5 @@ const (
 	NewCtlConnRes
 	HeartbeatReq
 	HeartbeatRes
+	NewWorkConnUdp
 )

src/models/msg/process.go

@@ -53,9 +53,9 @@ func Join(c1 *conn.Conn, c2 *conn.Conn) {
 }
 
 // join two connections and do some operations
-func JoinMore(c1 *conn.Conn, c2 *conn.Conn, conf config.BaseConf, needRecord bool) {
+func JoinMore(c1 io.ReadWriteCloser, c2 io.ReadWriteCloser, conf config.BaseConf, needRecord bool) {
 	var wait sync.WaitGroup
-	encryptPipe := func(from *conn.Conn, to *conn.Conn) {
+	encryptPipe := func(from io.ReadCloser, to io.WriteCloser) {
 		defer from.Close()
 		defer to.Close()
 		defer wait.Done()
@@ -64,7 +64,7 @@ func JoinMore(c1 *conn.Conn, c2 *conn.Conn, conf config.BaseConf, needRecord boo
 		pipeEncrypt(from, to, conf, needRecord)
 	}
 
-	decryptPipe := func(to *conn.Conn, from *conn.Conn) {
+	decryptPipe := func(to io.ReadCloser, from io.WriteCloser) {
 		defer from.Close()
 		defer to.Close()
 		defer wait.Done()
@@ -109,7 +109,7 @@ func unpkgMsg(data []byte) (int, []byte, []byte) {
 }
 
 // decrypt msg from reader, then write into writer
-func pipeDecrypt(r *conn.Conn, w *conn.Conn, conf config.BaseConf, needRecord bool) (err error) {
+func pipeDecrypt(r io.Reader, w io.Writer, conf config.BaseConf, needRecord bool) (err error) {
 	laes := new(pcrypto.Pcrypto)
 	key := conf.AuthToken
 	if conf.PrivilegeMode {
@@ -175,7 +175,7 @@ func pipeDecrypt(r *conn.Conn, w *conn.Conn, conf config.BaseConf, needRecord bo
 			}
 		}
 
-		_, err = w.WriteBytes(res)
+		_, err = w.Write(res)
 		if err != nil {
 			return err
 		}
@@ -192,7 +192,7 @@ func pipeDecrypt(r *conn.Conn, w *conn.Conn, conf config.BaseConf, needRecord bo
 }
 
 // recvive msg from reader, then encrypt msg into writer
-func pipeEncrypt(r *conn.Conn, w *conn.Conn, conf config.BaseConf, needRecord bool) (err error) {
+func pipeEncrypt(r io.Reader, w io.Writer, conf config.BaseConf, needRecord bool) (err error) {
 	laes := new(pcrypto.Pcrypto)
 	key := conf.AuthToken
 	if conf.PrivilegeMode {
@@ -247,7 +247,7 @@ func pipeEncrypt(r *conn.Conn, w *conn.Conn, conf config.BaseConf, needRecord bo
 		}
 
 		res = pkgMsg(res)
-		_, err = w.WriteBytes(res)
+		_, err = w.Write(res)
 		if err != nil {
 			return err
 		}

src/models/msg/udp.go

@@ -0,0 +1,72 @@
+// Copyright 2016 fatedier, fatedier@gmail.com
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package msg
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"net"
+)
+
+type UdpPacket struct {
+	Content []byte       `json:"-"`
+	Src     *net.UDPAddr `json:"-"`
+	Dst     *net.UDPAddr `json:"-"`
+
+	EncodeContent string `json:"content"`
+	SrcStr        string `json:"src"`
+	DstStr        string `json:"dst"`
+}
+
+func NewUdpPacket(content []byte, src, dst *net.UDPAddr) *UdpPacket {
+	up := &UdpPacket{
+		Src:           src,
+		Dst:           dst,
+		EncodeContent: base64.StdEncoding.EncodeToString(content),
+		SrcStr:        src.String(),
+		DstStr:        dst.String(),
+	}
+	return up
+}
+
+// parse one udp packet struct to bytes
+func (up *UdpPacket) Pack() []byte {
+	b, _ := json.Marshal(up)
+	return b
+}
+
+// parse from bytes to UdpPacket struct
+func (up *UdpPacket) UnPack(packet []byte) error {
+	err := json.Unmarshal(packet, &up)
+	if err != nil {
+		return err
+	}
+
+	up.Content, err = base64.StdEncoding.DecodeString(up.EncodeContent)
+	if err != nil {
+		return err
+	}
+
+	up.Src, err = net.ResolveUDPAddr("udp", up.SrcStr)
+	if err != nil {
+		return err
+	}
+
+	up.Dst, err = net.ResolveUDPAddr("udp", up.DstStr)
+	if err != nil {
+		return err
+	}
+	return nil
+}

src/models/msg/udp_test.go

@@ -0,0 +1,50 @@
+// Copyright 2016 fatedier, fatedier@gmail.com
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package msg
+
+import (
+	"net"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+var (
+	content string = "udp packet test"
+	src     string = "1.1.1.1:1000"
+	dst     string = "2.2.2.2:2000"
+
+	udpMsg *UdpPacket
+)
+
+func init() {
+	srcAddr, _ := net.ResolveUDPAddr("udp", src)
+	dstAddr, _ := net.ResolveUDPAddr("udp", dst)
+	udpMsg = NewUdpPacket([]byte(content), srcAddr, dstAddr)
+}
+
+func TestPack(t *testing.T) {
+	assert := assert.New(t)
+	msg := udpMsg.Pack()
+	assert.Equal(string(msg), `{"content":"dWRwIHBhY2tldCB0ZXN0","src":"1.1.1.1:1000","dst":"2.2.2.2:2000"}`)
+}
+
+func TestUnpack(t *testing.T) {
+	assert := assert.New(t)
+	udpMsg.UnPack([]byte(`{"content":"dWRwIHBhY2tldCB0ZXN0","src":"1.1.1.1:1000","dst":"2.2.2.2:2000"}`))
+	assert.Equal(content, string(udpMsg.Content))
+	assert.Equal(src, udpMsg.Src.String())
+	assert.Equal(dst, udpMsg.Dst.String())
+}

src/models/server/config.go

@@ -252,7 +252,7 @@ func loadProxyConf(confFile string) (proxyServers map[string]*ProxyServer, err e
 
 			proxyServer.Type, ok = section["type"]
 			if ok {
-				if proxyServer.Type != "tcp" && proxyServer.Type != "http" && proxyServer.Type != "https" {
+				if proxyServer.Type != "tcp" && proxyServer.Type != "http" && proxyServer.Type != "https" && proxyServer.Type != "udp" {
 					return proxyServers, fmt.Errorf("Parse conf error: proxy [%s] type error", proxyServer.Name)
 				}
 			} else {
@@ -264,8 +264,8 @@ func loadProxyConf(confFile string) (proxyServers map[string]*ProxyServer, err e
 				return proxyServers, fmt.Errorf("Parse conf error: proxy [%s] no auth_token found", proxyServer.Name)
 			}
 
-			// for tcp
-			if proxyServer.Type == "tcp" {
+			// for tcp and udp
+			if proxyServer.Type == "tcp" || proxyServer.Type == "udp" {
 				proxyServer.BindAddr, ok = section["bind_addr"]
 				if !ok {
 					proxyServer.BindAddr = "0.0.0.0"

src/models/server/server.go

@@ -16,6 +16,7 @@ package server
 
 import (
 	"fmt"
+	"net"
 	"sync"
 	"time"
 
@@ -25,6 +26,7 @@ import (
 	"github.com/fatedier/frp/src/models/msg"
 	"github.com/fatedier/frp/src/utils/conn"
 	"github.com/fatedier/frp/src/utils/log"
+	"github.com/fatedier/frp/src/utils/pool"
 )
 
 type Listener interface {
@@ -38,13 +40,17 @@ type ProxyServer struct {
 	ListenPort    int64
 	CustomDomains []string
 
-	Status       int64
-	CtlConn      *conn.Conn      // control connection with frpc
-	listeners    []Listener      // accept new connection from remote users
-	ctlMsgChan   chan int64      // every time accept a new user conn, put "1" to the channel
-	workConnChan chan *conn.Conn // get new work conns from control goroutine
-	mutex        sync.RWMutex
-	closeChan    chan struct{} // for notify other goroutines that the proxy is closed by close this channel
+	Status      int64
+	CtlConn     *conn.Conn // control connection with frpc
+	WorkConnUdp *conn.Conn // work connection for udp
+
+	udpConn       *net.UDPConn
+	listeners     []Listener      // accept new connection from remote users
+	ctlMsgChan    chan int64      // every time accept a new user conn, put "1" to the channel
+	workConnChan  chan *conn.Conn // get new work conns from control goroutine
+	udpSenderChan chan *msg.UdpPacket
+	mutex         sync.RWMutex
+	closeChan     chan struct{} // close this channel for notifying other goroutines that the proxy is closed
 }
 
 func NewProxyServer() (p *ProxyServer) {
@@ -83,6 +89,7 @@ func (p *ProxyServer) Init() {
 	metric.SetStatus(p.Name, p.Status)
 	p.workConnChan = make(chan *conn.Conn, p.PoolCount+10)
 	p.ctlMsgChan = make(chan int64, p.PoolCount+10)
+	p.udpSenderChan = make(chan *msg.UdpPacket, 1024)
 	p.listeners = make([]Listener, 0)
 	p.closeChan = make(chan struct{})
 	p.Unlock()
@@ -158,41 +165,68 @@ func (p *ProxyServer) Start(c *conn.Conn) (err error) {
 		go p.connectionPoolManager(p.closeChan)
 	}
 
-	// start a goroutine for every listener to accept user connection
-	for _, listener := range p.listeners {
-		go func(l Listener) {
+	if p.Type == "udp" {
+		// udp is special
+		p.udpConn, err = conn.ListenUDP(p.BindAddr, p.ListenPort)
+		if err != nil {
+			log.Warn("ProxyName [%s], listen udp port error: %v", p.Name, err)
+			return err
+		}
+		go func() {
 			for {
-				// block
-				// if listener is closed, err returned
-				c, err := l.Accept()
+				buf := pool.GetBuf(2048)
+				n, remoteAddr, err := p.udpConn.ReadFromUDP(buf)
 				if err != nil {
-					log.Info("ProxyName [%s], listener is closed", p.Name)
+					log.Info("ProxyName [%s], udp listener is closed", p.Name)
 					return
 				}
-				log.Debug("ProxyName [%s], get one new user conn [%s]", p.Name, c.GetRemoteAddr())
-
-				if p.Status != consts.Working {
-					log.Debug("ProxyName [%s] is not working, new user conn close", p.Name)
-					c.Close()
-					return
+				localAddr, _ := net.ResolveUDPAddr("udp", p.udpConn.LocalAddr().String())
+				udpPacket := msg.NewUdpPacket(buf[0:n], remoteAddr, localAddr)
+				select {
+				case p.udpSenderChan <- udpPacket:
+				default:
+					log.Warn("ProxyName [%s], udp sender channel is full", p.Name)
 				}
-
-				go func(userConn *conn.Conn) {
-					workConn, err := p.getWorkConn()
+				pool.PutBuf(buf)
+			}
+		}()
+	} else {
+		// start a goroutine for every listener to accept user connection
+		for _, listener := range p.listeners {
+			go func(l Listener) {
+				for {
+					// block
+					// if listener is closed, err returned
+					c, err := l.Accept()
 					if err != nil {
+						log.Info("ProxyName [%s], listener is closed", p.Name)
 						return
 					}
+					log.Debug("ProxyName [%s], get one new user conn [%s]", p.Name, c.GetRemoteAddr())
 
-					// message will be transferred to another without modifying
-					// l means local, r means remote
-					log.Debug("Join two connections, (l[%s] r[%s]) (l[%s] r[%s])", workConn.GetLocalAddr(), workConn.GetRemoteAddr(),
-						userConn.GetLocalAddr(), userConn.GetRemoteAddr())
+					if p.Status != consts.Working {
+						log.Debug("ProxyName [%s] is not working, new user conn close", p.Name)
+						c.Close()
+						return
+					}
 
-					needRecord := true
-					go msg.JoinMore(userConn, workConn, p.BaseConf, needRecord)
-				}(c)
-			}
-		}(listener)
+					go func(userConn *conn.Conn) {
+						workConn, err := p.getWorkConn()
+						if err != nil {
+							return
+						}
+
+						// message will be transferred to another without modifying
+						// l means local, r means remote
+						log.Debug("Join two connections, (l[%s] r[%s]) (l[%s] r[%s])", workConn.GetLocalAddr(), workConn.GetRemoteAddr(),
+							userConn.GetLocalAddr(), userConn.GetRemoteAddr())
+
+						needRecord := true
+						go msg.JoinMore(userConn, workConn, p.BaseConf, needRecord)
+					}(c)
+				}
+			}(listener)
+		}
 	}
 	return nil
 }
@@ -208,10 +242,18 @@ func (p *ProxyServer) Close() {
 		}
 		close(p.ctlMsgChan)
 		close(p.workConnChan)
+		close(p.udpSenderChan)
 		close(p.closeChan)
 		if p.CtlConn != nil {
 			p.CtlConn.Close()
 		}
+		if p.WorkConnUdp != nil {
+			p.WorkConnUdp.Close()
+		}
+		if p.udpConn != nil {
+			p.udpConn.Close()
+			p.udpConn = nil
+		}
 	}
 	metric.SetStatus(p.Name, p.Status)
 	// if the proxy created by PrivilegeMode, delete it when closed
@@ -236,7 +278,58 @@ func (p *ProxyServer) RegisterNewWorkConn(c *conn.Conn) {
 	case p.workConnChan <- c:
 	default:
 		log.Debug("ProxyName [%s], workConnChan is full, so close this work connection", p.Name)
+		c.Close()
+	}
+}
+
+// create a tcp connection for forwarding udp packages
+func (p *ProxyServer) RegisterNewWorkConnUdp(c *conn.Conn) {
+	if p.WorkConnUdp != nil && !p.WorkConnUdp.IsClosed() {
+		p.WorkConnUdp.Close()
 	}
+	p.WorkConnUdp = c
+
+	// read
+	go func() {
+		var (
+			buf string
+			err error
+		)
+		for {
+			buf, err = c.ReadLine()
+			if err != nil {
+				log.Warn("ProxyName [%s], work connection for udp closed", p.Name)
+				return
+			}
+			udpPacket := &msg.UdpPacket{}
+			err = udpPacket.UnPack([]byte(buf))
+			if err != nil {
+				log.Warn("ProxyName [%s], unpack udp packet error: %v", p.Name, err)
+				continue
+			}
+
+			// send to user
+			_, err = p.udpConn.WriteToUDP(udpPacket.Content, udpPacket.Dst)
+			if err != nil {
+				continue
+			}
+		}
+	}()
+
+	// write
+	go func() {
+		for {
+			udpPacket, ok := <-p.udpSenderChan
+			if !ok {
+				return
+			}
+			err := c.WriteString(string(udpPacket.Pack()) + "\n")
+			if err != nil {
+				log.Debug("ProxyName [%s], write to work connection for udp error: %v", p.Name, err)
+				return
+			}
+		}
+	}()
 }
 
 // When frps get one user connection, we get one work connection from the pool and return it.

src/utils/conn/conn.go

@@ -202,12 +202,12 @@ func (c *Conn) ReadLine() (buff string, err error) {
 	return buff, err
 }
 
-func (c *Conn) WriteBytes(content []byte) (n int, err error) {
+func (c *Conn) Write(content []byte) (n int, err error) {
 	n, err = c.TcpConn.Write(content)
 	return
 }
 
-func (c *Conn) Write(content string) (err error) {
+func (c *Conn) WriteString(content string) (err error) {
 	_, err = c.TcpConn.Write([]byte(content))
 	return err
 }
@@ -220,13 +220,14 @@ func (c *Conn) SetReadDeadline(t time.Time) error {
 	return c.TcpConn.SetReadDeadline(t)
 }
 
-func (c *Conn) Close() {
+func (c *Conn) Close() error {
 	c.mutex.Lock()
+	defer c.mutex.Unlock()
 	if c.TcpConn != nil && c.closeFlag == false {
 		c.closeFlag = true
 		c.TcpConn.Close()
 	}
-	c.mutex.Unlock()
+	return nil
 }
 
 func (c *Conn) IsClosed() (closeFlag bool) {
@@ -245,7 +246,6 @@ func (c *Conn) CheckClosed() bool {
 	}
 	c.mutex.RUnlock()
 
-	// err := c.TcpConn.SetReadDeadline(time.Now().Add(100 * time.Microsecond))
 	err := c.TcpConn.SetReadDeadline(time.Now().Add(time.Millisecond))
 	if err != nil {
 		c.Close()

src/utils/conn/udp_conn.go

@@ -0,0 +1,29 @@
+// Copyright 2016 fatedier, fatedier@gmail.com
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package conn
+
+import (
+	"fmt"
+	"net"
+)
+
+func ListenUDP(bindAddr string, bindPort int64) (conn *net.UDPConn, err error) {
+	udpAddr, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", bindAddr, bindPort))
+	if err != nil {
+		return conn, err
+	}
+	conn, err = net.ListenUDP("udp", udpAddr)
+	return
+}

test/echo_server.go

@@ -40,6 +40,6 @@ func echoWorker(c *conn.Conn) {
 			return
 		}
 
-		c.Write(buff)
+		c.WriteString(buff)
 	}
 }

test/func_test.go

@@ -26,7 +26,7 @@ func TestEchoServer(t *testing.T) {
 	timer := time.Now().Add(time.Duration(5) * time.Second)
 	c.SetDeadline(timer)
 
-	c.Write(ECHO_TEST_STR)
+	c.WriteString(ECHO_TEST_STR)
 
 	buff, err := c.ReadLine()
 	if err != nil {

vendor/github.com/davecgh/go-spew/LICENSE

@@ -0,0 +1,15 @@
+ISC License
+
+Copyright (c) 2012-2016 Dave Collins <dave@davec.name>
+
+Permission to use, copy, modify, and distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

vendor/github.com/davecgh/go-spew/spew/bypass.go

@@ -0,0 +1,152 @@
+// Copyright (c) 2015-2016 Dave Collins <dave@davec.name>
+//
+// Permission to use, copy, modify, and distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+// NOTE: Due to the following build constraints, this file will only be compiled
+// when the code is not running on Google App Engine, compiled by GopherJS, and
+// "-tags safe" is not added to the go build command line.  The "disableunsafe"
+// tag is deprecated and thus should not be used.
+// +build !js,!appengine,!safe,!disableunsafe
+
+package spew
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+const (
+	// UnsafeDisabled is a build-time constant which specifies whether or
+	// not access to the unsafe package is available.
+	UnsafeDisabled = false
+
+	// ptrSize is the size of a pointer on the current arch.
+	ptrSize = unsafe.Sizeof((*byte)(nil))
+)
+
+var (
+	// offsetPtr, offsetScalar, and offsetFlag are the offsets for the
+	// internal reflect.Value fields.  These values are valid before golang
+	// commit ecccf07e7f9d which changed the format.  The are also valid
+	// after commit 82f48826c6c7 which changed the format again to mirror
+	// the original format.  Code in the init function updates these offsets
+	// as necessary.
+	offsetPtr    = uintptr(ptrSize)
+	offsetScalar = uintptr(0)
+	offsetFlag   = uintptr(ptrSize * 2)
+
+	// flagKindWidth and flagKindShift indicate various bits that the
+	// reflect package uses internally to track kind information.
+	//
+	// flagRO indicates whether or not the value field of a reflect.Value is
+	// read-only.
+	//
+	// flagIndir indicates whether the value field of a reflect.Value is
+	// the actual data or a pointer to the data.
+	//
+	// These values are valid before golang commit 90a7c3c86944 which
+	// changed their positions.  Code in the init function updates these
+	// flags as necessary.
+	flagKindWidth = uintptr(5)
+	flagKindShift = uintptr(flagKindWidth - 1)
+	flagRO        = uintptr(1 << 0)
+	flagIndir     = uintptr(1 << 1)
+)
+
+func init() {
+	// Older versions of reflect.Value stored small integers directly in the
+	// ptr field (which is named val in the older versions).  Versions
+	// between commits ecccf07e7f9d and 82f48826c6c7 added a new field named
+	// scalar for this purpose which unfortunately came before the flag
+	// field, so the offset of the flag field is different for those
+	// versions.
+	//
+	// This code constructs a new reflect.Value from a known small integer
+	// and checks if the size of the reflect.Value struct indicates it has
+	// the scalar field. When it does, the offsets are updated accordingly.
+	vv := reflect.ValueOf(0xf00)
+	if unsafe.Sizeof(vv) == (ptrSize * 4) {
+		offsetScalar = ptrSize * 2
+		offsetFlag = ptrSize * 3
+	}
+
+	// Commit 90a7c3c86944 changed the flag positions such that the low
+	// order bits are the kind.  This code extracts the kind from the flags
+	// field and ensures it's the correct type.  When it's not, the flag
+	// order has been changed to the newer format, so the flags are updated
+	// accordingly.
+	upf := unsafe.Pointer(uintptr(unsafe.Pointer(&vv)) + offsetFlag)
+	upfv := *(*uintptr)(upf)
+	flagKindMask := uintptr((1<<flagKindWidth - 1) << flagKindShift)
+	if (upfv&flagKindMask)>>flagKindShift != uintptr(reflect.Int) {
+		flagKindShift = 0
+		flagRO = 1 << 5
+		flagIndir = 1 << 6
+
+		// Commit adf9b30e5594 modified the flags to separate the
+		// flagRO flag into two bits which specifies whether or not the
+		// field is embedded.  This causes flagIndir to move over a bit
+		// and means that flagRO is the combination of either of the
+		// original flagRO bit and the new bit.
+		//
+		// This code detects the change by extracting what used to be
+		// the indirect bit to ensure it's set.  When it's not, the flag
+		// order has been changed to the newer format, so the flags are
+		// updated accordingly.
+		if upfv&flagIndir == 0 {
+			flagRO = 3 << 5
+			flagIndir = 1 << 7
+		}
+	}
+}
+
+// unsafeReflectValue converts the passed reflect.Value into a one that bypasses
+// the typical safety restrictions preventing access to unaddressable and
+// unexported data.  It works by digging the raw pointer to the underlying
+// value out of the protected value and generating a new unprotected (unsafe)
+// reflect.Value to it.
+//
+// This allows us to check for implementations of the Stringer and error
+// interfaces to be used for pretty printing ordinarily unaddressable and
+// inaccessible values such as unexported struct fields.
+func unsafeReflectValue(v reflect.Value) (rv reflect.Value) {
+	indirects := 1
+	vt := v.Type()
+	upv := unsafe.Pointer(uintptr(unsafe.Pointer(&v)) + offsetPtr)
+	rvf := *(*uintptr)(unsafe.Pointer(uintptr(unsafe.Pointer(&v)) + offsetFlag))
+	if rvf&flagIndir != 0 {
+		vt = reflect.PtrTo(v.Type())
+		indirects++
+	} else if offsetScalar != 0 {
+		// The value is in the scalar field when it's not one of the
+		// reference types.
+		switch vt.Kind() {
+		case reflect.Uintptr:
+		case reflect.Chan:
+		case reflect.Func:
+		case reflect.Map:
+		case reflect.Ptr:
+		case reflect.UnsafePointer:
+		default:
+			upv = unsafe.Pointer(uintptr(unsafe.Pointer(&v)) +
+				offsetScalar)
+		}
+	}
+
+	pv := reflect.NewAt(vt, upv)
+	rv = pv
+	for i := 0; i < indirects; i++ {
+		rv = rv.Elem()
+	}
+	return rv
+}

vendor/github.com/davecgh/go-spew/spew/bypasssafe.go

@@ -0,0 +1,38 @@
+// Copyright (c) 2015-2016 Dave Collins <dave@davec.name>
+//
+// Permission to use, copy, modify, and distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+// NOTE: Due to the following build constraints, this file will only be compiled
+// when the code is running on Google App Engine, compiled by GopherJS, or
+// "-tags safe" is added to the go build command line.  The "disableunsafe"
+// tag is deprecated and thus should not be used.
+// +build js appengine safe disableunsafe
+
+package spew
+
+import "reflect"
+
+const (
+	// UnsafeDisabled is a build-time constant which specifies whether or
+	// not access to the unsafe package is available.
+	UnsafeDisabled = true
+)
+
+// unsafeReflectValue typically converts the passed reflect.Value into a one
+// that bypasses the typical safety restrictions preventing access to
+// unaddressable and unexported data.  However, doing this relies on access to
+// the unsafe package.  This is a stub version which simply returns the passed
+// reflect.Value when the unsafe package is not available.
+func unsafeReflectValue(v reflect.Value) reflect.Value {
+	return v
+}

vendor/github.com/davecgh/go-spew/spew/common.go

@@ -0,0 +1,341 @@
+/*
+ * Copyright (c) 2013-2016 Dave Collins <dave@davec.name>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+package spew
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"reflect"
+	"sort"
+	"strconv"
+)
+
+// Some constants in the form of bytes to avoid string overhead.  This mirrors
+// the technique used in the fmt package.
+var (
+	panicBytes            = []byte("(PANIC=")
+	plusBytes             = []byte("+")
+	iBytes                = []byte("i")
+	trueBytes             = []byte("true")
+	falseBytes            = []byte("false")
+	interfaceBytes        = []byte("(interface {})")
+	commaNewlineBytes     = []byte(",\n")
+	newlineBytes          = []byte("\n")
+	openBraceBytes        = []byte("{")
+	openBraceNewlineBytes = []byte("{\n")
+	closeBraceBytes       = []byte("}")
+	asteriskBytes         = []byte("*")
+	colonBytes            = []byte(":")
+	colonSpaceBytes       = []byte(": ")
+	openParenBytes        = []byte("(")
+	closeParenBytes       = []byte(")")
+	spaceBytes            = []byte(" ")
+	pointerChainBytes     = []byte("->")
+	nilAngleBytes         = []byte("<nil>")
+	maxNewlineBytes       = []byte("<max depth reached>\n")
+	maxShortBytes         = []byte("<max>")
+	circularBytes         = []byte("<already shown>")
+	circularShortBytes    = []byte("<shown>")
+	invalidAngleBytes     = []byte("<invalid>")
+	openBracketBytes      = []byte("[")
+	closeBracketBytes     = []byte("]")
+	percentBytes          = []byte("%")
+	precisionBytes        = []byte(".")
+	openAngleBytes        = []byte("<")
+	closeAngleBytes       = []byte(">")
+	openMapBytes          = []byte("map[")
+	closeMapBytes         = []byte("]")
+	lenEqualsBytes        = []byte("len=")
+	capEqualsBytes        = []byte("cap=")
+)
+
+// hexDigits is used to map a decimal value to a hex digit.
+var hexDigits = "0123456789abcdef"
+
+// catchPanic handles any panics that might occur during the handleMethods
+// calls.
+func catchPanic(w io.Writer, v reflect.Value) {
+	if err := recover(); err != nil {
+		w.Write(panicBytes)
+		fmt.Fprintf(w, "%v", err)
+		w.Write(closeParenBytes)
+	}
+}
+
+// handleMethods attempts to call the Error and String methods on the underlying
+// type the passed reflect.Value represents and outputes the result to Writer w.
+//
+// It handles panics in any called methods by catching and displaying the error
+// as the formatted value.
+func handleMethods(cs *ConfigState, w io.Writer, v reflect.Value) (handled bool) {
+	// We need an interface to check if the type implements the error or
+	// Stringer interface.  However, the reflect package won't give us an
+	// interface on certain things like unexported struct fields in order
+	// to enforce visibility rules.  We use unsafe, when it's available,
+	// to bypass these restrictions since this package does not mutate the
+	// values.
+	if !v.CanInterface() {
+		if UnsafeDisabled {
+			return false
+		}
+
+		v = unsafeReflectValue(v)
+	}
+
+	// Choose whether or not to do error and Stringer interface lookups against
+	// the base type or a pointer to the base type depending on settings.
+	// Technically calling one of these methods with a pointer receiver can
+	// mutate the value, however, types which choose to satisify an error or
+	// Stringer interface with a pointer receiver should not be mutating their
+	// state inside these interface methods.
+	if !cs.DisablePointerMethods && !UnsafeDisabled && !v.CanAddr() {
+		v = unsafeReflectValue(v)
+	}
+	if v.CanAddr() {
+		v = v.Addr()
+	}
+
+	// Is it an error or Stringer?
+	switch iface := v.Interface().(type) {
+	case error:
+		defer catchPanic(w, v)
+		if cs.ContinueOnMethod {
+			w.Write(openParenBytes)
+			w.Write([]byte(iface.Error()))
+			w.Write(closeParenBytes)
+			w.Write(spaceBytes)
+			return false
+		}
+
+		w.Write([]byte(iface.Error()))
+		return true
+
+	case fmt.Stringer:
+		defer catchPanic(w, v)
+		if cs.ContinueOnMethod {
+			w.Write(openParenBytes)
+			w.Write([]byte(iface.String()))
+			w.Write(closeParenBytes)
+			w.Write(spaceBytes)
+			return false
+		}
+		w.Write([]byte(iface.String()))
+		return true
+	}
+	return false
+}
+
+// printBool outputs a boolean value as true or false to Writer w.
+func printBool(w io.Writer, val bool) {
+	if val {
+		w.Write(trueBytes)
+	} else {
+		w.Write(falseBytes)
+	}
+}
+
+// printInt outputs a signed integer value to Writer w.
+func printInt(w io.Writer, val int64, base int) {
+	w.Write([]byte(strconv.FormatInt(val, base)))
+}
+
+// printUint outputs an unsigned integer value to Writer w.
+func printUint(w io.Writer, val uint64, base int) {
+	w.Write([]byte(strconv.FormatUint(val, base)))
+}
+
+// printFloat outputs a floating point value using the specified precision,
+// which is expected to be 32 or 64bit, to Writer w.
+func printFloat(w io.Writer, val float64, precision int) {
+	w.Write([]byte(strconv.FormatFloat(val, 'g', -1, precision)))
+}
+
+// printComplex outputs a complex value using the specified float precision
+// for the real and imaginary parts to Writer w.
+func printComplex(w io.Writer, c complex128, floatPrecision int) {
+	r := real(c)
+	w.Write(openParenBytes)
+	w.Write([]byte(strconv.FormatFloat(r, 'g', -1, floatPrecision)))
+	i := imag(c)
+	if i >= 0 {
+		w.Write(plusBytes)
+	}
+	w.Write([]byte(strconv.FormatFloat(i, 'g', -1, floatPrecision)))
+	w.Write(iBytes)
+	w.Write(closeParenBytes)
+}
+
+// printHexPtr outputs a uintptr formatted as hexidecimal with a leading '0x'
+// prefix to Writer w.
+func printHexPtr(w io.Writer, p uintptr) {
+	// Null pointer.
+	num := uint64(p)
+	if num == 0 {
+		w.Write(nilAngleBytes)
+		return
+	}
+
+	// Max uint64 is 16 bytes in hex + 2 bytes for '0x' prefix
+	buf := make([]byte, 18)
+
+	// It's simpler to construct the hex string right to left.
+	base := uint64(16)
+	i := len(buf) - 1
+	for num >= base {
+		buf[i] = hexDigits[num%base]
+		num /= base
+		i--
+	}
+	buf[i] = hexDigits[num]
+
+	// Add '0x' prefix.
+	i--
+	buf[i] = 'x'
+	i--
+	buf[i] = '0'
+
+	// Strip unused leading bytes.
+	buf = buf[i:]
+	w.Write(buf)
+}
+
+// valuesSorter implements sort.Interface to allow a slice of reflect.Value
+// elements to be sorted.
+type valuesSorter struct {
+	values  []reflect.Value
+	strings []string // either nil or same len and values
+	cs      *ConfigState
+}
+
+// newValuesSorter initializes a valuesSorter instance, which holds a set of
+// surrogate keys on which the data should be sorted.  It uses flags in
+// ConfigState to decide if and how to populate those surrogate keys.
+func newValuesSorter(values []reflect.Value, cs *ConfigState) sort.Interface {
+	vs := &valuesSorter{values: values, cs: cs}
+	if canSortSimply(vs.values[0].Kind()) {
+		return vs
+	}
+	if !cs.DisableMethods {
+		vs.strings = make([]string, len(values))
+		for i := range vs.values {
+			b := bytes.Buffer{}
+			if !handleMethods(cs, &b, vs.values[i]) {
+				vs.strings = nil
+				break
+			}
+			vs.strings[i] = b.String()
+		}
+	}
+	if vs.strings == nil && cs.SpewKeys {
+		vs.strings = make([]string, len(values))
+		for i := range vs.values {
+			vs.strings[i] = Sprintf("%#v", vs.values[i].Interface())
+		}
+	}
+	return vs
+}
+
+// canSortSimply tests whether a reflect.Kind is a primitive that can be sorted
+// directly, or whether it should be considered for sorting by surrogate keys
+// (if the ConfigState allows it).
+func canSortSimply(kind reflect.Kind) bool {
+	// This switch parallels valueSortLess, except for the default case.
+	switch kind {
+	case reflect.Bool:
+		return true
+	case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int:
+		return true
+	case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint:
+		return true
+	case reflect.Float32, reflect.Float64:
+		return true
+	case reflect.String:
+		return true
+	case reflect.Uintptr:
+		return true
+	case reflect.Array:
+		return true
+	}
+	return false
+}
+
+// Len returns the number of values in the slice.  It is part of the
+// sort.Interface implementation.
+func (s *valuesSorter) Len() int {
+	return len(s.values)
+}
+
+// Swap swaps the values at the passed indices.  It is part of the
+// sort.Interface implementation.
+func (s *valuesSorter) Swap(i, j int) {
+	s.values[i], s.values[j] = s.values[j], s.values[i]
+	if s.strings != nil {
+		s.strings[i], s.strings[j] = s.strings[j], s.strings[i]
+	}
+}
+
+// valueSortLess returns whether the first value should sort before the second
+// value.  It is used by valueSorter.Less as part of the sort.Interface
+// implementation.
+func valueSortLess(a, b reflect.Value) bool {
+	switch a.Kind() {
+	case reflect.Bool:
+		return !a.Bool() && b.Bool()
+	case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int:
+		return a.Int() < b.Int()
+	case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint:
+		return a.Uint() < b.Uint()
+	case reflect.Float32, reflect.Float64:
+		return a.Float() < b.Float()
+	case reflect.String:
+		return a.String() < b.String()
+	case reflect.Uintptr:
+		return a.Uint() < b.Uint()
+	case reflect.Array:
+		// Compare the contents of both arrays.
+		l := a.Len()
+		for i := 0; i < l; i++ {
+			av := a.Index(i)
+			bv := b.Index(i)
+			if av.Interface() == bv.Interface() {
+				continue
+			}
+			return valueSortLess(av, bv)
+		}
+	}
+	return a.String() < b.String()
+}
+
+// Less returns whether the value at index i should sort before the
+// value at index j.  It is part of the sort.Interface implementation.
+func (s *valuesSorter) Less(i, j int) bool {
+	if s.strings == nil {
+		return valueSortLess(s.values[i], s.values[j])
+	}
+	return s.strings[i] < s.strings[j]
+}
+
+// sortValues is a sort function that handles both native types and any type that
+// can be converted to error or Stringer.  Other inputs are sorted according to
+// their Value.String() value to ensure display stability.
+func sortValues(values []reflect.Value, cs *ConfigState) {
+	if len(values) == 0 {
+		return
+	}
+	sort.Sort(newValuesSorter(values, cs))
+}

vendor/github.com/davecgh/go-spew/spew/config.go

@@ -0,0 +1,306 @@
+/*
+ * Copyright (c) 2013-2016 Dave Collins <dave@davec.name>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+package spew
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+)
+
+// ConfigState houses the configuration options used by spew to format and
+// display values.  There is a global instance, Config, that is used to control
+// all top-level Formatter and Dump functionality.  Each ConfigState instance
+// provides methods equivalent to the top-level functions.
+//
+// The zero value for ConfigState provides no indentation.  You would typically
+// want to set it to a space or a tab.
+//
+// Alternatively, you can use NewDefaultConfig to get a ConfigState instance
+// with default settings.  See the documentation of NewDefaultConfig for default
+// values.
+type ConfigState struct {
+	// Indent specifies the string to use for each indentation level.  The
+	// global config instance that all top-level functions use set this to a
+	// single space by default.  If you would like more indentation, you might
+	// set this to a tab with "\t" or perhaps two spaces with "  ".
+	Indent string
+
+	// MaxDepth controls the maximum number of levels to descend into nested
+	// data structures.  The default, 0, means there is no limit.
+	//
+	// NOTE: Circular data structures are properly detected, so it is not
+	// necessary to set this value unless you specifically want to limit deeply
+	// nested data structures.
+	MaxDepth int
+
+	// DisableMethods specifies whether or not error and Stringer interfaces are
+	// invoked for types that implement them.
+	DisableMethods bool
+
+	// DisablePointerMethods specifies whether or not to check for and invoke
+	// error and Stringer interfaces on types which only accept a pointer
+	// receiver when the current type is not a pointer.
+	//
+	// NOTE: This might be an unsafe action since calling one of these methods
+	// with a pointer receiver could technically mutate the value, however,
+	// in practice, types which choose to satisify an error or Stringer
+	// interface with a pointer receiver should not be mutating their state
+	// inside these interface methods.  As a result, this option relies on
+	// access to the unsafe package, so it will not have any effect when
+	// running in environments without access to the unsafe package such as
+	// Google App Engine or with the "safe" build tag specified.
+	DisablePointerMethods bool
+
+	// DisablePointerAddresses specifies whether to disable the printing of
+	// pointer addresses. This is useful when diffing data structures in tests.
+	DisablePointerAddresses bool
+
+	// DisableCapacities specifies whether to disable the printing of capacities
+	// for arrays, slices, maps and channels. This is useful when diffing
+	// data structures in tests.
+	DisableCapacities bool
+
+	// ContinueOnMethod specifies whether or not recursion should continue once
+	// a custom error or Stringer interface is invoked.  The default, false,
+	// means it will print the results of invoking the custom error or Stringer
+	// interface and return immediately instead of continuing to recurse into
+	// the internals of the data type.
+	//
+	// NOTE: This flag does not have any effect if method invocation is disabled
+	// via the DisableMethods or DisablePointerMethods options.
+	ContinueOnMethod bool
+
+	// SortKeys specifies map keys should be sorted before being printed. Use
+	// this to have a more deterministic, diffable output.  Note that only
+	// native types (bool, int, uint, floats, uintptr and string) and types
+	// that support the error or Stringer interfaces (if methods are
+	// enabled) are supported, with other types sorted according to the
+	// reflect.Value.String() output which guarantees display stability.
+	SortKeys bool
+
+	// SpewKeys specifies that, as a last resort attempt, map keys should
+	// be spewed to strings and sorted by those strings.  This is only
+	// considered if SortKeys is true.
+	SpewKeys bool
+}
+
+// Config is the active configuration of the top-level functions.
+// The configuration can be changed by modifying the contents of spew.Config.
+var Config = ConfigState{Indent: " "}
+
+// Errorf is a wrapper for fmt.Errorf that treats each argument as if it were
+// passed with a Formatter interface returned by c.NewFormatter.  It returns
+// the formatted string as a value that satisfies error.  See NewFormatter
+// for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Errorf(format, c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Errorf(format string, a ...interface{}) (err error) {
+	return fmt.Errorf(format, c.convertArgs(a)...)
+}
+
+// Fprint is a wrapper for fmt.Fprint that treats each argument as if it were
+// passed with a Formatter interface returned by c.NewFormatter.  It returns
+// the number of bytes written and any write error encountered.  See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Fprint(w, c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Fprint(w io.Writer, a ...interface{}) (n int, err error) {
+	return fmt.Fprint(w, c.convertArgs(a)...)
+}
+
+// Fprintf is a wrapper for fmt.Fprintf that treats each argument as if it were
+// passed with a Formatter interface returned by c.NewFormatter.  It returns
+// the number of bytes written and any write error encountered.  See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Fprintf(w, format, c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Fprintf(w io.Writer, format string, a ...interface{}) (n int, err error) {
+	return fmt.Fprintf(w, format, c.convertArgs(a)...)
+}
+
+// Fprintln is a wrapper for fmt.Fprintln that treats each argument as if it
+// passed with a Formatter interface returned by c.NewFormatter.  See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Fprintln(w, c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Fprintln(w io.Writer, a ...interface{}) (n int, err error) {
+	return fmt.Fprintln(w, c.convertArgs(a)...)
+}
+
+// Print is a wrapper for fmt.Print that treats each argument as if it were
+// passed with a Formatter interface returned by c.NewFormatter.  It returns
+// the number of bytes written and any write error encountered.  See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Print(c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Print(a ...interface{}) (n int, err error) {
+	return fmt.Print(c.convertArgs(a)...)
+}
+
+// Printf is a wrapper for fmt.Printf that treats each argument as if it were
+// passed with a Formatter interface returned by c.NewFormatter.  It returns
+// the number of bytes written and any write error encountered.  See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Printf(format, c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Printf(format string, a ...interface{}) (n int, err error) {
+	return fmt.Printf(format, c.convertArgs(a)...)
+}
+
+// Println is a wrapper for fmt.Println that treats each argument as if it were
+// passed with a Formatter interface returned by c.NewFormatter.  It returns
+// the number of bytes written and any write error encountered.  See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Println(c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Println(a ...interface{}) (n int, err error) {
+	return fmt.Println(c.convertArgs(a)...)
+}
+
+// Sprint is a wrapper for fmt.Sprint that treats each argument as if it were
+// passed with a Formatter interface returned by c.NewFormatter.  It returns
+// the resulting string.  See NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Sprint(c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Sprint(a ...interface{}) string {
+	return fmt.Sprint(c.convertArgs(a)...)
+}
+
+// Sprintf is a wrapper for fmt.Sprintf that treats each argument as if it were
+// passed with a Formatter interface returned by c.NewFormatter.  It returns
+// the resulting string.  See NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Sprintf(format, c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Sprintf(format string, a ...interface{}) string {
+	return fmt.Sprintf(format, c.convertArgs(a)...)
+}
+
+// Sprintln is a wrapper for fmt.Sprintln that treats each argument as if it
+// were passed with a Formatter interface returned by c.NewFormatter.  It
+// returns the resulting string.  See NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Sprintln(c.NewFormatter(a), c.NewFormatter(b))
+func (c *ConfigState) Sprintln(a ...interface{}) string {
+	return fmt.Sprintln(c.convertArgs(a)...)
+}
+
+/*
+NewFormatter returns a custom formatter that satisfies the fmt.Formatter
+interface.  As a result, it integrates cleanly with standard fmt package
+printing functions.  The formatter is useful for inline printing of smaller data
+types similar to the standard %v format specifier.
+
+The custom formatter only responds to the %v (most compact), %+v (adds pointer
+addresses), %#v (adds types), and %#+v (adds types and pointer addresses) verb
+combinations.  Any other verbs such as %x and %q will be sent to the the
+standard fmt package for formatting.  In addition, the custom formatter ignores
+the width and precision arguments (however they will still work on the format
+specifiers not handled by the custom formatter).
+
+Typically this function shouldn't be called directly.  It is much easier to make
+use of the custom formatter by calling one of the convenience functions such as
+c.Printf, c.Println, or c.Printf.
+*/
+func (c *ConfigState) NewFormatter(v interface{}) fmt.Formatter {
+	return newFormatter(c, v)
+}
+
+// Fdump formats and displays the passed arguments to io.Writer w.  It formats
+// exactly the same as Dump.
+func (c *ConfigState) Fdump(w io.Writer, a ...interface{}) {
+	fdump(c, w, a...)
+}
+
+/*
+Dump displays the passed parameters to standard out with newlines, customizable
+indentation, and additional debug information such as complete types and all
+pointer addresses used to indirect to the final value.  It provides the
+following features over the built-in printing facilities provided by the fmt
+package:
+
+	* Pointers are dereferenced and followed
+	* Circular data structures are detected and handled properly
+	* Custom Stringer/error interfaces are optionally invoked, including
+	  on unexported types
+	* Custom types which only implement the Stringer/error interfaces via
+	  a pointer receiver are optionally invoked when passing non-pointer
+	  variables
+	* Byte arrays and slices are dumped like the hexdump -C command which
+	  includes offsets, byte values in hex, and ASCII output
+
+The configuration options are controlled by modifying the public members
+of c.  See ConfigState for options documentation.
+
+See Fdump if you would prefer dumping to an arbitrary io.Writer or Sdump to
+get the formatted result as a string.
+*/
+func (c *ConfigState) Dump(a ...interface{}) {
+	fdump(c, os.Stdout, a...)
+}
+
+// Sdump returns a string with the passed arguments formatted exactly the same
+// as Dump.
+func (c *ConfigState) Sdump(a ...interface{}) string {
+	var buf bytes.Buffer
+	fdump(c, &buf, a...)
+	return buf.String()
+}
+
+// convertArgs accepts a slice of arguments and returns a slice of the same
+// length with each argument converted to a spew Formatter interface using
+// the ConfigState associated with s.
+func (c *ConfigState) convertArgs(args []interface{}) (formatters []interface{}) {
+	formatters = make([]interface{}, len(args))
+	for index, arg := range args {
+		formatters[index] = newFormatter(c, arg)
+	}
+	return formatters
+}
+
+// NewDefaultConfig returns a ConfigState with the following default settings.
+//
+// 	Indent: " "
+// 	MaxDepth: 0
+// 	DisableMethods: false
+// 	DisablePointerMethods: false
+// 	ContinueOnMethod: false
+// 	SortKeys: false
+func NewDefaultConfig() *ConfigState {
+	return &ConfigState{Indent: " "}
+}

vendor/github.com/davecgh/go-spew/spew/doc.go

@@ -0,0 +1,211 @@
+/*
+ * Copyright (c) 2013-2016 Dave Collins <dave@davec.name>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+Package spew implements a deep pretty printer for Go data structures to aid in
+debugging.
+
+A quick overview of the additional features spew provides over the built-in
+printing facilities for Go data types are as follows:
+
+	* Pointers are dereferenced and followed
+	* Circular data structures are detected and handled properly
+	* Custom Stringer/error interfaces are optionally invoked, including
+	  on unexported types
+	* Custom types which only implement the Stringer/error interfaces via
+	  a pointer receiver are optionally invoked when passing non-pointer
+	  variables
+	* Byte arrays and slices are dumped like the hexdump -C command which
+	  includes offsets, byte values in hex, and ASCII output (only when using
+	  Dump style)
+
+There are two different approaches spew allows for dumping Go data structures:
+
+	* Dump style which prints with newlines, customizable indentation,
+	  and additional debug information such as types and all pointer addresses
+	  used to indirect to the final value
+	* A custom Formatter interface that integrates cleanly with the standard fmt
+	  package and replaces %v, %+v, %#v, and %#+v to provide inline printing
+	  similar to the default %v while providing the additional functionality
+	  outlined above and passing unsupported format verbs such as %x and %q
+	  along to fmt
+
+Quick Start
+
+This section demonstrates how to quickly get started with spew.  See the
+sections below for further details on formatting and configuration options.
+
+To dump a variable with full newlines, indentation, type, and pointer
+information use Dump, Fdump, or Sdump:
+	spew.Dump(myVar1, myVar2, ...)
+	spew.Fdump(someWriter, myVar1, myVar2, ...)
+	str := spew.Sdump(myVar1, myVar2, ...)
+
+Alternatively, if you would prefer to use format strings with a compacted inline
+printing style, use the convenience wrappers Printf, Fprintf, etc with
+%v (most compact), %+v (adds pointer addresses), %#v (adds types), or
+%#+v (adds types and pointer addresses):
+	spew.Printf("myVar1: %v -- myVar2: %+v", myVar1, myVar2)
+	spew.Printf("myVar3: %#v -- myVar4: %#+v", myVar3, myVar4)
+	spew.Fprintf(someWriter, "myVar1: %v -- myVar2: %+v", myVar1, myVar2)
+	spew.Fprintf(someWriter, "myVar3: %#v -- myVar4: %#+v", myVar3, myVar4)
+
+Configuration Options
+
+Configuration of spew is handled by fields in the ConfigState type.  For
+convenience, all of the top-level functions use a global state available
+via the spew.Config global.
+
+It is also possible to create a ConfigState instance that provides methods
+equivalent to the top-level functions.  This allows concurrent configuration
+options.  See the ConfigState documentation for more details.
+
+The following configuration options are available:
+	* Indent
+		String to use for each indentation level for Dump functions.
+		It is a single space by default.  A popular alternative is "\t".
+
+	* MaxDepth
+		Maximum number of levels to descend into nested data structures.
+		There is no limit by default.
+
+	* DisableMethods
+		Disables invocation of error and Stringer interface methods.
+		Method invocation is enabled by default.
+
+	* DisablePointerMethods
+		Disables invocation of error and Stringer interface methods on types
+		which only accept pointer receivers from non-pointer variables.
+		Pointer method invocation is enabled by default.
+
+	* DisablePointerAddresses
+		DisablePointerAddresses specifies whether to disable the printing of
+		pointer addresses. This is useful when diffing data structures in tests.
+
+	* DisableCapacities
+		DisableCapacities specifies whether to disable the printing of
+		capacities for arrays, slices, maps and channels. This is useful when
+		diffing data structures in tests.
+
+	* ContinueOnMethod
+		Enables recursion into types after invoking error and Stringer interface
+		methods. Recursion after method invocation is disabled by default.
+
+	* SortKeys
+		Specifies map keys should be sorted before being printed. Use
+		this to have a more deterministic, diffable output.  Note that
+		only native types (bool, int, uint, floats, uintptr and string)
+		and types which implement error or Stringer interfaces are
+		supported with other types sorted according to the
+		reflect.Value.String() output which guarantees display
+		stability.  Natural map order is used by default.
+
+	* SpewKeys
+		Specifies that, as a last resort attempt, map keys should be
+		spewed to strings and sorted by those strings.  This is only
+		considered if SortKeys is true.
+
+Dump Usage
+
+Simply call spew.Dump with a list of variables you want to dump:
+
+	spew.Dump(myVar1, myVar2, ...)
+
+You may also call spew.Fdump if you would prefer to output to an arbitrary
+io.Writer.  For example, to dump to standard error:
+
+	spew.Fdump(os.Stderr, myVar1, myVar2, ...)
+
+A third option is to call spew.Sdump to get the formatted output as a string:
+
+	str := spew.Sdump(myVar1, myVar2, ...)
+
+Sample Dump Output
+
+See the Dump example for details on the setup of the types and variables being
+shown here.
+
+	(main.Foo) {
+	 unexportedField: (*main.Bar)(0xf84002e210)({
+	  flag: (main.Flag) flagTwo,
+	  data: (uintptr) <nil>
+	 }),
+	 ExportedField: (map[interface {}]interface {}) (len=1) {
+	  (string) (len=3) "one": (bool) true
+	 }
+	}
+
+Byte (and uint8) arrays and slices are displayed uniquely like the hexdump -C
+command as shown.
+	([]uint8) (len=32 cap=32) {
+	 00000000  11 12 13 14 15 16 17 18  19 1a 1b 1c 1d 1e 1f 20  |............... |
+	 00000010  21 22 23 24 25 26 27 28  29 2a 2b 2c 2d 2e 2f 30  |!"#$%&'()*+,-./0|
+	 00000020  31 32                                             |12|
+	}
+
+Custom Formatter
+
+Spew provides a custom formatter that implements the fmt.Formatter interface
+so that it integrates cleanly with standard fmt package printing functions. The
+formatter is useful for inline printing of smaller data types similar to the
+standard %v format specifier.
+
+The custom formatter only responds to the %v (most compact), %+v (adds pointer
+addresses), %#v (adds types), or %#+v (adds types and pointer addresses) verb
+combinations.  Any other verbs such as %x and %q will be sent to the the
+standard fmt package for formatting.  In addition, the custom formatter ignores
+the width and precision arguments (however they will still work on the format
+specifiers not handled by the custom formatter).
+
+Custom Formatter Usage
+
+The simplest way to make use of the spew custom formatter is to call one of the
+convenience functions such as spew.Printf, spew.Println, or spew.Printf.  The
+functions have syntax you are most likely already familiar with:
+
+	spew.Printf("myVar1: %v -- myVar2: %+v", myVar1, myVar2)
+	spew.Printf("myVar3: %#v -- myVar4: %#+v", myVar3, myVar4)
+	spew.Println(myVar, myVar2)
+	spew.Fprintf(os.Stderr, "myVar1: %v -- myVar2: %+v", myVar1, myVar2)
+	spew.Fprintf(os.Stderr, "myVar3: %#v -- myVar4: %#+v", myVar3, myVar4)
+
+See the Index for the full list convenience functions.
+
+Sample Formatter Output
+
+Double pointer to a uint8:
+	  %v: <**>5
+	 %+v: <**>(0xf8400420d0->0xf8400420c8)5
+	 %#v: (**uint8)5
+	%#+v: (**uint8)(0xf8400420d0->0xf8400420c8)5
+
+Pointer to circular struct with a uint8 field and a pointer to itself:
+	  %v: <*>{1 <*><shown>}
+	 %+v: <*>(0xf84003e260){ui8:1 c:<*>(0xf84003e260)<shown>}
+	 %#v: (*main.circular){ui8:(uint8)1 c:(*main.circular)<shown>}
+	%#+v: (*main.circular)(0xf84003e260){ui8:(uint8)1 c:(*main.circular)(0xf84003e260)<shown>}
+
+See the Printf example for details on the setup of variables being shown
+here.
+
+Errors
+
+Since it is possible for custom Stringer/error interfaces to panic, spew
+detects them and handles them internally by printing the panic information
+inline with the output.  Since spew is intended to provide deep pretty printing
+capabilities on structures, it intentionally does not return any errors.
+*/
+package spew

vendor/github.com/davecgh/go-spew/spew/dump.go

@@ -0,0 +1,509 @@
+/*
+ * Copyright (c) 2013-2016 Dave Collins <dave@davec.name>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+package spew
+
+import (
+	"bytes"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"os"
+	"reflect"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+var (
+	// uint8Type is a reflect.Type representing a uint8.  It is used to
+	// convert cgo types to uint8 slices for hexdumping.
+	uint8Type = reflect.TypeOf(uint8(0))
+
+	// cCharRE is a regular expression that matches a cgo char.
+	// It is used to detect character arrays to hexdump them.
+	cCharRE = regexp.MustCompile("^.*\\._Ctype_char$")
+
+	// cUnsignedCharRE is a regular expression that matches a cgo unsigned
+	// char.  It is used to detect unsigned character arrays to hexdump
+	// them.
+	cUnsignedCharRE = regexp.MustCompile("^.*\\._Ctype_unsignedchar$")
+
+	// cUint8tCharRE is a regular expression that matches a cgo uint8_t.
+	// It is used to detect uint8_t arrays to hexdump them.
+	cUint8tCharRE = regexp.MustCompile("^.*\\._Ctype_uint8_t$")
+)
+
+// dumpState contains information about the state of a dump operation.
+type dumpState struct {
+	w                io.Writer
+	depth            int
+	pointers         map[uintptr]int
+	ignoreNextType   bool
+	ignoreNextIndent bool
+	cs               *ConfigState
+}
+
+// indent performs indentation according to the depth level and cs.Indent
+// option.
+func (d *dumpState) indent() {
+	if d.ignoreNextIndent {
+		d.ignoreNextIndent = false
+		return
+	}
+	d.w.Write(bytes.Repeat([]byte(d.cs.Indent), d.depth))
+}
+
+// unpackValue returns values inside of non-nil interfaces when possible.
+// This is useful for data types like structs, arrays, slices, and maps which
+// can contain varying types packed inside an interface.
+func (d *dumpState) unpackValue(v reflect.Value) reflect.Value {
+	if v.Kind() == reflect.Interface && !v.IsNil() {
+		v = v.Elem()
+	}
+	return v
+}
+
+// dumpPtr handles formatting of pointers by indirecting them as necessary.
+func (d *dumpState) dumpPtr(v reflect.Value) {
+	// Remove pointers at or below the current depth from map used to detect
+	// circular refs.
+	for k, depth := range d.pointers {
+		if depth >= d.depth {
+			delete(d.pointers, k)
+		}
+	}
+
+	// Keep list of all dereferenced pointers to show later.
+	pointerChain := make([]uintptr, 0)
+
+	// Figure out how many levels of indirection there are by dereferencing
+	// pointers and unpacking interfaces down the chain while detecting circular
+	// references.
+	nilFound := false
+	cycleFound := false
+	indirects := 0
+	ve := v
+	for ve.Kind() == reflect.Ptr {
+		if ve.IsNil() {
+			nilFound = true
+			break
+		}
+		indirects++
+		addr := ve.Pointer()
+		pointerChain = append(pointerChain, addr)
+		if pd, ok := d.pointers[addr]; ok && pd < d.depth {
+			cycleFound = true
+			indirects--
+			break
+		}
+		d.pointers[addr] = d.depth
+
+		ve = ve.Elem()
+		if ve.Kind() == reflect.Interface {
+			if ve.IsNil() {
+				nilFound = true
+				break
+			}
+			ve = ve.Elem()
+		}
+	}
+
+	// Display type information.
+	d.w.Write(openParenBytes)
+	d.w.Write(bytes.Repeat(asteriskBytes, indirects))
+	d.w.Write([]byte(ve.Type().String()))
+	d.w.Write(closeParenBytes)
+
+	// Display pointer information.
+	if !d.cs.DisablePointerAddresses && len(pointerChain) > 0 {
+		d.w.Write(openParenBytes)
+		for i, addr := range pointerChain {
+			if i > 0 {
+				d.w.Write(pointerChainBytes)
+			}
+			printHexPtr(d.w, addr)
+		}
+		d.w.Write(closeParenBytes)
+	}
+
+	// Display dereferenced value.
+	d.w.Write(openParenBytes)
+	switch {
+	case nilFound == true:
+		d.w.Write(nilAngleBytes)
+
+	case cycleFound == true:
+		d.w.Write(circularBytes)
+
+	default:
+		d.ignoreNextType = true
+		d.dump(ve)
+	}
+	d.w.Write(closeParenBytes)
+}
+
+// dumpSlice handles formatting of arrays and slices.  Byte (uint8 under
+// reflection) arrays and slices are dumped in hexdump -C fashion.
+func (d *dumpState) dumpSlice(v reflect.Value) {
+	// Determine whether this type should be hex dumped or not.  Also,
+	// for types which should be hexdumped, try to use the underlying data
+	// first, then fall back to trying to convert them to a uint8 slice.
+	var buf []uint8
+	doConvert := false
+	doHexDump := false
+	numEntries := v.Len()
+	if numEntries > 0 {
+		vt := v.Index(0).Type()
+		vts := vt.String()
+		switch {
+		// C types that need to be converted.
+		case cCharRE.MatchString(vts):
+			fallthrough
+		case cUnsignedCharRE.MatchString(vts):
+			fallthrough
+		case cUint8tCharRE.MatchString(vts):
+			doConvert = true
+
+		// Try to use existing uint8 slices and fall back to converting
+		// and copying if that fails.
+		case vt.Kind() == reflect.Uint8:
+			// We need an addressable interface to convert the type
+			// to a byte slice.  However, the reflect package won't
+			// give us an interface on certain things like
+			// unexported struct fields in order to enforce
+			// visibility rules.  We use unsafe, when available, to
+			// bypass these restrictions since this package does not
+			// mutate the values.
+			vs := v
+			if !vs.CanInterface() || !vs.CanAddr() {
+				vs = unsafeReflectValue(vs)
+			}
+			if !UnsafeDisabled {
+				vs = vs.Slice(0, numEntries)
+
+				// Use the existing uint8 slice if it can be
+				// type asserted.
+				iface := vs.Interface()
+				if slice, ok := iface.([]uint8); ok {
+					buf = slice
+					doHexDump = true
+					break
+				}
+			}
+
+			// The underlying data needs to be converted if it can't
+			// be type asserted to a uint8 slice.
+			doConvert = true
+		}
+
+		// Copy and convert the underlying type if needed.
+		if doConvert && vt.ConvertibleTo(uint8Type) {
+			// Convert and copy each element into a uint8 byte
+			// slice.
+			buf = make([]uint8, numEntries)
+			for i := 0; i < numEntries; i++ {
+				vv := v.Index(i)
+				buf[i] = uint8(vv.Convert(uint8Type).Uint())
+			}
+			doHexDump = true
+		}
+	}
+
+	// Hexdump the entire slice as needed.
+	if doHexDump {
+		indent := strings.Repeat(d.cs.Indent, d.depth)
+		str := indent + hex.Dump(buf)
+		str = strings.Replace(str, "\n", "\n"+indent, -1)
+		str = strings.TrimRight(str, d.cs.Indent)
+		d.w.Write([]byte(str))
+		return
+	}
+
+	// Recursively call dump for each item.
+	for i := 0; i < numEntries; i++ {
+		d.dump(d.unpackValue(v.Index(i)))
+		if i < (numEntries - 1) {
+			d.w.Write(commaNewlineBytes)
+		} else {
+			d.w.Write(newlineBytes)
+		}
+	}
+}
+
+// dump is the main workhorse for dumping a value.  It uses the passed reflect
+// value to figure out what kind of object we are dealing with and formats it
+// appropriately.  It is a recursive function, however circular data structures
+// are detected and handled properly.
+func (d *dumpState) dump(v reflect.Value) {
+	// Handle invalid reflect values immediately.
+	kind := v.Kind()
+	if kind == reflect.Invalid {
+		d.w.Write(invalidAngleBytes)
+		return
+	}
+
+	// Handle pointers specially.
+	if kind == reflect.Ptr {
+		d.indent()
+		d.dumpPtr(v)
+		return
+	}
+
+	// Print type information unless already handled elsewhere.
+	if !d.ignoreNextType {
+		d.indent()
+		d.w.Write(openParenBytes)
+		d.w.Write([]byte(v.Type().String()))
+		d.w.Write(closeParenBytes)
+		d.w.Write(spaceBytes)
+	}
+	d.ignoreNextType = false
+
+	// Display length and capacity if the built-in len and cap functions
+	// work with the value's kind and the len/cap itself is non-zero.
+	valueLen, valueCap := 0, 0
+	switch v.Kind() {
+	case reflect.Array, reflect.Slice, reflect.Chan:
+		valueLen, valueCap = v.Len(), v.Cap()
+	case reflect.Map, reflect.String:
+		valueLen = v.Len()
+	}
+	if valueLen != 0 || !d.cs.DisableCapacities && valueCap != 0 {
+		d.w.Write(openParenBytes)
+		if valueLen != 0 {
+			d.w.Write(lenEqualsBytes)
+			printInt(d.w, int64(valueLen), 10)
+		}
+		if !d.cs.DisableCapacities && valueCap != 0 {
+			if valueLen != 0 {
+				d.w.Write(spaceBytes)
+			}
+			d.w.Write(capEqualsBytes)
+			printInt(d.w, int64(valueCap), 10)
+		}
+		d.w.Write(closeParenBytes)
+		d.w.Write(spaceBytes)
+	}
+
+	// Call Stringer/error interfaces if they exist and the handle methods flag
+	// is enabled
+	if !d.cs.DisableMethods {
+		if (kind != reflect.Invalid) && (kind != reflect.Interface) {
+			if handled := handleMethods(d.cs, d.w, v); handled {
+				return
+			}
+		}
+	}
+
+	switch kind {
+	case reflect.Invalid:
+		// Do nothing.  We should never get here since invalid has already
+		// been handled above.
+
+	case reflect.Bool:
+		printBool(d.w, v.Bool())
+
+	case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int:
+		printInt(d.w, v.Int(), 10)
+
+	case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint:
+		printUint(d.w, v.Uint(), 10)
+
+	case reflect.Float32:
+		printFloat(d.w, v.Float(), 32)
+
+	case reflect.Float64:
+		printFloat(d.w, v.Float(), 64)
+
+	case reflect.Complex64:
+		printComplex(d.w, v.Complex(), 32)
+
+	case reflect.Complex128:
+		printComplex(d.w, v.Complex(), 64)
+
+	case reflect.Slice:
+		if v.IsNil() {
+			d.w.Write(nilAngleBytes)
+			break
+		}
+		fallthrough
+
+	case reflect.Array:
+		d.w.Write(openBraceNewlineBytes)
+		d.depth++
+		if (d.cs.MaxDepth != 0) && (d.depth > d.cs.MaxDepth) {
+			d.indent()
+			d.w.Write(maxNewlineBytes)
+		} else {
+			d.dumpSlice(v)
+		}
+		d.depth--
+		d.indent()
+		d.w.Write(closeBraceBytes)
+
+	case reflect.String:
+		d.w.Write([]byte(strconv.Quote(v.String())))
+
+	case reflect.Interface:
+		// The only time we should get here is for nil interfaces due to
+		// unpackValue calls.
+		if v.IsNil() {
+			d.w.Write(nilAngleBytes)
+		}
+
+	case reflect.Ptr:
+		// Do nothing.  We should never get here since pointers have already
+		// been handled above.
+
+	case reflect.Map:
+		// nil maps should be indicated as different than empty maps
+		if v.IsNil() {
+			d.w.Write(nilAngleBytes)
+			break
+		}
+
+		d.w.Write(openBraceNewlineBytes)
+		d.depth++
+		if (d.cs.MaxDepth != 0) && (d.depth > d.cs.MaxDepth) {
+			d.indent()
+			d.w.Write(maxNewlineBytes)
+		} else {
+			numEntries := v.Len()
+			keys := v.MapKeys()
+			if d.cs.SortKeys {
+				sortValues(keys, d.cs)
+			}
+			for i, key := range keys {
+				d.dump(d.unpackValue(key))
+				d.w.Write(colonSpaceBytes)
+				d.ignoreNextIndent = true
+				d.dump(d.unpackValue(v.MapIndex(key)))
+				if i < (numEntries - 1) {
+					d.w.Write(commaNewlineBytes)
+				} else {
+					d.w.Write(newlineBytes)
+				}
+			}
+		}
+		d.depth--
+		d.indent()
+		d.w.Write(closeBraceBytes)
+
+	case reflect.Struct:
+		d.w.Write(openBraceNewlineBytes)
+		d.depth++
+		if (d.cs.MaxDepth != 0) && (d.depth > d.cs.MaxDepth) {
+			d.indent()
+			d.w.Write(maxNewlineBytes)
+		} else {
+			vt := v.Type()
+			numFields := v.NumField()
+			for i := 0; i < numFields; i++ {
+				d.indent()
+				vtf := vt.Field(i)
+				d.w.Write([]byte(vtf.Name))
+				d.w.Write(colonSpaceBytes)
+				d.ignoreNextIndent = true
+				d.dump(d.unpackValue(v.Field(i)))
+				if i < (numFields - 1) {
+					d.w.Write(commaNewlineBytes)
+				} else {
+					d.w.Write(newlineBytes)
+				}
+			}
+		}
+		d.depth--
+		d.indent()
+		d.w.Write(closeBraceBytes)
+
+	case reflect.Uintptr:
+		printHexPtr(d.w, uintptr(v.Uint()))
+
+	case reflect.UnsafePointer, reflect.Chan, reflect.Func:
+		printHexPtr(d.w, v.Pointer())
+
+	// There were not any other types at the time this code was written, but
+	// fall back to letting the default fmt package handle it in case any new
+	// types are added.
+	default:
+		if v.CanInterface() {
+			fmt.Fprintf(d.w, "%v", v.Interface())
+		} else {
+			fmt.Fprintf(d.w, "%v", v.String())
+		}
+	}
+}
+
+// fdump is a helper function to consolidate the logic from the various public
+// methods which take varying writers and config states.
+func fdump(cs *ConfigState, w io.Writer, a ...interface{}) {
+	for _, arg := range a {
+		if arg == nil {
+			w.Write(interfaceBytes)
+			w.Write(spaceBytes)
+			w.Write(nilAngleBytes)
+			w.Write(newlineBytes)
+			continue
+		}
+
+		d := dumpState{w: w, cs: cs}
+		d.pointers = make(map[uintptr]int)
+		d.dump(reflect.ValueOf(arg))
+		d.w.Write(newlineBytes)
+	}
+}
+
+// Fdump formats and displays the passed arguments to io.Writer w.  It formats
+// exactly the same as Dump.
+func Fdump(w io.Writer, a ...interface{}) {
+	fdump(&Config, w, a...)
+}
+
+// Sdump returns a string with the passed arguments formatted exactly the same
+// as Dump.
+func Sdump(a ...interface{}) string {
+	var buf bytes.Buffer
+	fdump(&Config, &buf, a...)
+	return buf.String()
+}
+
+/*
+Dump displays the passed parameters to standard out with newlines, customizable
+indentation, and additional debug information such as complete types and all
+pointer addresses used to indirect to the final value.  It provides the
+following features over the built-in printing facilities provided by the fmt
+package:
+
+	* Pointers are dereferenced and followed
+	* Circular data structures are detected and handled properly
+	* Custom Stringer/error interfaces are optionally invoked, including
+	  on unexported types
+	* Custom types which only implement the Stringer/error interfaces via
+	  a pointer receiver are optionally invoked when passing non-pointer
+	  variables
+	* Byte arrays and slices are dumped like the hexdump -C command which
+	  includes offsets, byte values in hex, and ASCII output
+
+The configuration options are controlled by an exported package global,
+spew.Config.  See ConfigState for options documentation.
+
+See Fdump if you would prefer dumping to an arbitrary io.Writer or Sdump to
+get the formatted result as a string.
+*/
+func Dump(a ...interface{}) {
+	fdump(&Config, os.Stdout, a...)
+}

vendor/github.com/davecgh/go-spew/spew/format.go

@@ -0,0 +1,419 @@
+/*
+ * Copyright (c) 2013-2016 Dave Collins <dave@davec.name>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+package spew
+
+import (
+	"bytes"
+	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
+)
+
+// supportedFlags is a list of all the character flags supported by fmt package.
+const supportedFlags = "0-+# "
+
+// formatState implements the fmt.Formatter interface and contains information
+// about the state of a formatting operation.  The NewFormatter function can
+// be used to get a new Formatter which can be used directly as arguments
+// in standard fmt package printing calls.
+type formatState struct {
+	value          interface{}
+	fs             fmt.State
+	depth          int
+	pointers       map[uintptr]int
+	ignoreNextType bool
+	cs             *ConfigState
+}
+
+// buildDefaultFormat recreates the original format string without precision
+// and width information to pass in to fmt.Sprintf in the case of an
+// unrecognized type.  Unless new types are added to the language, this
+// function won't ever be called.
+func (f *formatState) buildDefaultFormat() (format string) {
+	buf := bytes.NewBuffer(percentBytes)
+
+	for _, flag := range supportedFlags {
+		if f.fs.Flag(int(flag)) {
+			buf.WriteRune(flag)
+		}
+	}
+
+	buf.WriteRune('v')
+
+	format = buf.String()
+	return format
+}
+
+// constructOrigFormat recreates the original format string including precision
+// and width information to pass along to the standard fmt package.  This allows
+// automatic deferral of all format strings this package doesn't support.
+func (f *formatState) constructOrigFormat(verb rune) (format string) {
+	buf := bytes.NewBuffer(percentBytes)
+
+	for _, flag := range supportedFlags {
+		if f.fs.Flag(int(flag)) {
+			buf.WriteRune(flag)
+		}
+	}
+
+	if width, ok := f.fs.Width(); ok {
+		buf.WriteString(strconv.Itoa(width))
+	}
+
+	if precision, ok := f.fs.Precision(); ok {
+		buf.Write(precisionBytes)
+		buf.WriteString(strconv.Itoa(precision))
+	}
+
+	buf.WriteRune(verb)
+
+	format = buf.String()
+	return format
+}
+
+// unpackValue returns values inside of non-nil interfaces when possible and
+// ensures that types for values which have been unpacked from an interface
+// are displayed when the show types flag is also set.
+// This is useful for data types like structs, arrays, slices, and maps which
+// can contain varying types packed inside an interface.
+func (f *formatState) unpackValue(v reflect.Value) reflect.Value {
+	if v.Kind() == reflect.Interface {
+		f.ignoreNextType = false
+		if !v.IsNil() {
+			v = v.Elem()
+		}
+	}
+	return v
+}
+
+// formatPtr handles formatting of pointers by indirecting them as necessary.
+func (f *formatState) formatPtr(v reflect.Value) {
+	// Display nil if top level pointer is nil.
+	showTypes := f.fs.Flag('#')
+	if v.IsNil() && (!showTypes || f.ignoreNextType) {
+		f.fs.Write(nilAngleBytes)
+		return
+	}
+
+	// Remove pointers at or below the current depth from map used to detect
+	// circular refs.
+	for k, depth := range f.pointers {
+		if depth >= f.depth {
+			delete(f.pointers, k)
+		}
+	}
+
+	// Keep list of all dereferenced pointers to possibly show later.
+	pointerChain := make([]uintptr, 0)
+
+	// Figure out how many levels of indirection there are by derferencing
+	// pointers and unpacking interfaces down the chain while detecting circular
+	// references.
+	nilFound := false
+	cycleFound := false
+	indirects := 0
+	ve := v
+	for ve.Kind() == reflect.Ptr {
+		if ve.IsNil() {
+			nilFound = true
+			break
+		}
+		indirects++
+		addr := ve.Pointer()
+		pointerChain = append(pointerChain, addr)
+		if pd, ok := f.pointers[addr]; ok && pd < f.depth {
+			cycleFound = true
+			indirects--
+			break
+		}
+		f.pointers[addr] = f.depth
+
+		ve = ve.Elem()
+		if ve.Kind() == reflect.Interface {
+			if ve.IsNil() {
+				nilFound = true
+				break
+			}
+			ve = ve.Elem()
+		}
+	}
+
+	// Display type or indirection level depending on flags.
+	if showTypes && !f.ignoreNextType {
+		f.fs.Write(openParenBytes)
+		f.fs.Write(bytes.Repeat(asteriskBytes, indirects))
+		f.fs.Write([]byte(ve.Type().String()))
+		f.fs.Write(closeParenBytes)
+	} else {
+		if nilFound || cycleFound {
+			indirects += strings.Count(ve.Type().String(), "*")
+		}
+		f.fs.Write(openAngleBytes)
+		f.fs.Write([]byte(strings.Repeat("*", indirects)))
+		f.fs.Write(closeAngleBytes)
+	}
+
+	// Display pointer information depending on flags.
+	if f.fs.Flag('+') && (len(pointerChain) > 0) {
+		f.fs.Write(openParenBytes)
+		for i, addr := range pointerChain {
+			if i > 0 {
+				f.fs.Write(pointerChainBytes)
+			}
+			printHexPtr(f.fs, addr)
+		}
+		f.fs.Write(closeParenBytes)
+	}
+
+	// Display dereferenced value.
+	switch {
+	case nilFound == true:
+		f.fs.Write(nilAngleBytes)
+
+	case cycleFound == true:
+		f.fs.Write(circularShortBytes)
+
+	default:
+		f.ignoreNextType = true
+		f.format(ve)
+	}
+}
+
+// format is the main workhorse for providing the Formatter interface.  It
+// uses the passed reflect value to figure out what kind of object we are
+// dealing with and formats it appropriately.  It is a recursive function,
+// however circular data structures are detected and handled properly.
+func (f *formatState) format(v reflect.Value) {
+	// Handle invalid reflect values immediately.
+	kind := v.Kind()
+	if kind == reflect.Invalid {
+		f.fs.Write(invalidAngleBytes)
+		return
+	}
+
+	// Handle pointers specially.
+	if kind == reflect.Ptr {
+		f.formatPtr(v)
+		return
+	}
+
+	// Print type information unless already handled elsewhere.
+	if !f.ignoreNextType && f.fs.Flag('#') {
+		f.fs.Write(openParenBytes)
+		f.fs.Write([]byte(v.Type().String()))
+		f.fs.Write(closeParenBytes)
+	}
+	f.ignoreNextType = false
+
+	// Call Stringer/error interfaces if they exist and the handle methods
+	// flag is enabled.
+	if !f.cs.DisableMethods {
+		if (kind != reflect.Invalid) && (kind != reflect.Interface) {
+			if handled := handleMethods(f.cs, f.fs, v); handled {
+				return
+			}
+		}
+	}
+
+	switch kind {
+	case reflect.Invalid:
+		// Do nothing.  We should never get here since invalid has already
+		// been handled above.
+
+	case reflect.Bool:
+		printBool(f.fs, v.Bool())
+
+	case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int:
+		printInt(f.fs, v.Int(), 10)
+
+	case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint:
+		printUint(f.fs, v.Uint(), 10)
+
+	case reflect.Float32:
+		printFloat(f.fs, v.Float(), 32)
+
+	case reflect.Float64:
+		printFloat(f.fs, v.Float(), 64)
+
+	case reflect.Complex64:
+		printComplex(f.fs, v.Complex(), 32)
+
+	case reflect.Complex128:
+		printComplex(f.fs, v.Complex(), 64)
+
+	case reflect.Slice:
+		if v.IsNil() {
+			f.fs.Write(nilAngleBytes)
+			break
+		}
+		fallthrough
+
+	case reflect.Array:
+		f.fs.Write(openBracketBytes)
+		f.depth++
+		if (f.cs.MaxDepth != 0) && (f.depth > f.cs.MaxDepth) {
+			f.fs.Write(maxShortBytes)
+		} else {
+			numEntries := v.Len()
+			for i := 0; i < numEntries; i++ {
+				if i > 0 {
+					f.fs.Write(spaceBytes)
+				}
+				f.ignoreNextType = true
+				f.format(f.unpackValue(v.Index(i)))
+			}
+		}
+		f.depth--
+		f.fs.Write(closeBracketBytes)
+
+	case reflect.String:
+		f.fs.Write([]byte(v.String()))
+
+	case reflect.Interface:
+		// The only time we should get here is for nil interfaces due to
+		// unpackValue calls.
+		if v.IsNil() {
+			f.fs.Write(nilAngleBytes)
+		}
+
+	case reflect.Ptr:
+		// Do nothing.  We should never get here since pointers have already
+		// been handled above.
+
+	case reflect.Map:
+		// nil maps should be indicated as different than empty maps
+		if v.IsNil() {
+			f.fs.Write(nilAngleBytes)
+			break
+		}
+
+		f.fs.Write(openMapBytes)
+		f.depth++
+		if (f.cs.MaxDepth != 0) && (f.depth > f.cs.MaxDepth) {
+			f.fs.Write(maxShortBytes)
+		} else {
+			keys := v.MapKeys()
+			if f.cs.SortKeys {
+				sortValues(keys, f.cs)
+			}
+			for i, key := range keys {
+				if i > 0 {
+					f.fs.Write(spaceBytes)
+				}
+				f.ignoreNextType = true
+				f.format(f.unpackValue(key))
+				f.fs.Write(colonBytes)
+				f.ignoreNextType = true
+				f.format(f.unpackValue(v.MapIndex(key)))
+			}
+		}
+		f.depth--
+		f.fs.Write(closeMapBytes)
+
+	case reflect.Struct:
+		numFields := v.NumField()
+		f.fs.Write(openBraceBytes)
+		f.depth++
+		if (f.cs.MaxDepth != 0) && (f.depth > f.cs.MaxDepth) {
+			f.fs.Write(maxShortBytes)
+		} else {
+			vt := v.Type()
+			for i := 0; i < numFields; i++ {
+				if i > 0 {
+					f.fs.Write(spaceBytes)
+				}
+				vtf := vt.Field(i)
+				if f.fs.Flag('+') || f.fs.Flag('#') {
+					f.fs.Write([]byte(vtf.Name))
+					f.fs.Write(colonBytes)
+				}
+				f.format(f.unpackValue(v.Field(i)))
+			}
+		}
+		f.depth--
+		f.fs.Write(closeBraceBytes)
+
+	case reflect.Uintptr:
+		printHexPtr(f.fs, uintptr(v.Uint()))
+
+	case reflect.UnsafePointer, reflect.Chan, reflect.Func:
+		printHexPtr(f.fs, v.Pointer())
+
+	// There were not any other types at the time this code was written, but
+	// fall back to letting the default fmt package handle it if any get added.
+	default:
+		format := f.buildDefaultFormat()
+		if v.CanInterface() {
+			fmt.Fprintf(f.fs, format, v.Interface())
+		} else {
+			fmt.Fprintf(f.fs, format, v.String())
+		}
+	}
+}
+
+// Format satisfies the fmt.Formatter interface. See NewFormatter for usage
+// details.
+func (f *formatState) Format(fs fmt.State, verb rune) {
+	f.fs = fs
+
+	// Use standard formatting for verbs that are not v.
+	if verb != 'v' {
+		format := f.constructOrigFormat(verb)
+		fmt.Fprintf(fs, format, f.value)
+		return
+	}
+
+	if f.value == nil {
+		if fs.Flag('#') {
+			fs.Write(interfaceBytes)
+		}
+		fs.Write(nilAngleBytes)
+		return
+	}
+
+	f.format(reflect.ValueOf(f.value))
+}
+
+// newFormatter is a helper function to consolidate the logic from the various
+// public methods which take varying config states.
+func newFormatter(cs *ConfigState, v interface{}) fmt.Formatter {
+	fs := &formatState{value: v, cs: cs}
+	fs.pointers = make(map[uintptr]int)
+	return fs
+}
+
+/*
+NewFormatter returns a custom formatter that satisfies the fmt.Formatter
+interface.  As a result, it integrates cleanly with standard fmt package
+printing functions.  The formatter is useful for inline printing of smaller data
+types similar to the standard %v format specifier.
+
+The custom formatter only responds to the %v (most compact), %+v (adds pointer
+addresses), %#v (adds types), or %#+v (adds types and pointer addresses) verb
+combinations.  Any other verbs such as %x and %q will be sent to the the
+standard fmt package for formatting.  In addition, the custom formatter ignores
+the width and precision arguments (however they will still work on the format
+specifiers not handled by the custom formatter).
+
+Typically this function shouldn't be called directly.  It is much easier to make
+use of the custom formatter by calling one of the convenience functions such as
+Printf, Println, or Fprintf.
+*/
+func NewFormatter(v interface{}) fmt.Formatter {
+	return newFormatter(&Config, v)
+}

vendor/github.com/davecgh/go-spew/spew/spew.go

@@ -0,0 +1,148 @@
+/*
+ * Copyright (c) 2013-2016 Dave Collins <dave@davec.name>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+package spew
+
+import (
+	"fmt"
+	"io"
+)
+
+// Errorf is a wrapper for fmt.Errorf that treats each argument as if it were
+// passed with a default Formatter interface returned by NewFormatter.  It
+// returns the formatted string as a value that satisfies error.  See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Errorf(format, spew.NewFormatter(a), spew.NewFormatter(b))
+func Errorf(format string, a ...interface{}) (err error) {
+	return fmt.Errorf(format, convertArgs(a)...)
+}
+
+// Fprint is a wrapper for fmt.Fprint that treats each argument as if it were
+// passed with a default Formatter interface returned by NewFormatter.  It
+// returns the number of bytes written and any write error encountered.  See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Fprint(w, spew.NewFormatter(a), spew.NewFormatter(b))
+func Fprint(w io.Writer, a ...interface{}) (n int, err error) {
+	return fmt.Fprint(w, convertArgs(a)...)
+}
+
+// Fprintf is a wrapper for fmt.Fprintf that treats each argument as if it were
+// passed with a default Formatter interface returned by NewFormatter.  It
+// returns the number of bytes written and any write error encountered.  See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Fprintf(w, format, spew.NewFormatter(a), spew.NewFormatter(b))
+func Fprintf(w io.Writer, format string, a ...interface{}) (n int, err error) {
+	return fmt.Fprintf(w, format, convertArgs(a)...)
+}
+
+// Fprintln is a wrapper for fmt.Fprintln that treats each argument as if it
+// passed with a default Formatter interface returned by NewFormatter.  See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Fprintln(w, spew.NewFormatter(a), spew.NewFormatter(b))
+func Fprintln(w io.Writer, a ...interface{}) (n int, err error) {
+	return fmt.Fprintln(w, convertArgs(a)...)
+}
+
+// Print is a wrapper for fmt.Print that treats each argument as if it were
+// passed with a default Formatter interface returned by NewFormatter.  It
+// returns the number of bytes written and any write error encountered.  See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Print(spew.NewFormatter(a), spew.NewFormatter(b))
+func Print(a ...interface{}) (n int, err error) {
+	return fmt.Print(convertArgs(a)...)
+}
+
+// Printf is a wrapper for fmt.Printf that treats each argument as if it were
+// passed with a default Formatter interface returned by NewFormatter.  It
+// returns the number of bytes written and any write error encountered.  See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Printf(format, spew.NewFormatter(a), spew.NewFormatter(b))
+func Printf(format string, a ...interface{}) (n int, err error) {
+	return fmt.Printf(format, convertArgs(a)...)
+}
+
+// Println is a wrapper for fmt.Println that treats each argument as if it were
+// passed with a default Formatter interface returned by NewFormatter.  It
+// returns the number of bytes written and any write error encountered.  See
+// NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Println(spew.NewFormatter(a), spew.NewFormatter(b))
+func Println(a ...interface{}) (n int, err error) {
+	return fmt.Println(convertArgs(a)...)
+}
+
+// Sprint is a wrapper for fmt.Sprint that treats each argument as if it were
+// passed with a default Formatter interface returned by NewFormatter.  It
+// returns the resulting string.  See NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Sprint(spew.NewFormatter(a), spew.NewFormatter(b))
+func Sprint(a ...interface{}) string {
+	return fmt.Sprint(convertArgs(a)...)
+}
+
+// Sprintf is a wrapper for fmt.Sprintf that treats each argument as if it were
+// passed with a default Formatter interface returned by NewFormatter.  It
+// returns the resulting string.  See NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Sprintf(format, spew.NewFormatter(a), spew.NewFormatter(b))
+func Sprintf(format string, a ...interface{}) string {
+	return fmt.Sprintf(format, convertArgs(a)...)
+}
+
+// Sprintln is a wrapper for fmt.Sprintln that treats each argument as if it
+// were passed with a default Formatter interface returned by NewFormatter.  It
+// returns the resulting string.  See NewFormatter for formatting details.
+//
+// This function is shorthand for the following syntax:
+//
+//	fmt.Sprintln(spew.NewFormatter(a), spew.NewFormatter(b))
+func Sprintln(a ...interface{}) string {
+	return fmt.Sprintln(convertArgs(a)...)
+}
+
+// convertArgs accepts a slice of arguments and returns a slice of the same
+// length with each argument converted to a default spew Formatter interface.
+func convertArgs(args []interface{}) (formatters []interface{}) {
+	formatters = make([]interface{}, len(args))
+	for index, arg := range args {
+		formatters[index] = NewFormatter(arg)
+	}
+	return formatters
+}

vendor/github.com/pmezard/go-difflib/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2013, Patrick Mezard
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+    Redistributions in binary form must reproduce the above copyright
+notice, this list of conditions and the following disclaimer in the
+documentation and/or other materials provided with the distribution.
+    The names of its contributors may not be used to endorse or promote
+products derived from this software without specific prior written
+permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/pmezard/go-difflib/difflib/difflib.go

@@ -0,0 +1,772 @@
+// Package difflib is a partial port of Python difflib module.
+//
+// It provides tools to compare sequences of strings and generate textual diffs.
+//
+// The following class and functions have been ported:
+//
+// - SequenceMatcher
+//
+// - unified_diff
+//
+// - context_diff
+//
+// Getting unified diffs was the main goal of the port. Keep in mind this code
+// is mostly suitable to output text differences in a human friendly way, there
+// are no guarantees generated diffs are consumable by patch(1).
+package difflib
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"strings"
+)
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func calculateRatio(matches, length int) float64 {
+	if length > 0 {
+		return 2.0 * float64(matches) / float64(length)
+	}
+	return 1.0
+}
+
+type Match struct {
+	A    int
+	B    int
+	Size int
+}
+
+type OpCode struct {
+	Tag byte
+	I1  int
+	I2  int
+	J1  int
+	J2  int
+}
+
+// SequenceMatcher compares sequence of strings. The basic
+// algorithm predates, and is a little fancier than, an algorithm
+// published in the late 1980's by Ratcliff and Obershelp under the
+// hyperbolic name "gestalt pattern matching".  The basic idea is to find
+// the longest contiguous matching subsequence that contains no "junk"
+// elements (R-O doesn't address junk).  The same idea is then applied
+// recursively to the pieces of the sequences to the left and to the right
+// of the matching subsequence.  This does not yield minimal edit
+// sequences, but does tend to yield matches that "look right" to people.
+//
+// SequenceMatcher tries to compute a "human-friendly diff" between two
+// sequences.  Unlike e.g. UNIX(tm) diff, the fundamental notion is the
+// longest *contiguous* & junk-free matching subsequence.  That's what
+// catches peoples' eyes.  The Windows(tm) windiff has another interesting
+// notion, pairing up elements that appear uniquely in each sequence.
+// That, and the method here, appear to yield more intuitive difference
+// reports than does diff.  This method appears to be the least vulnerable
+// to synching up on blocks of "junk lines", though (like blank lines in
+// ordinary text files, or maybe "<P>" lines in HTML files).  That may be
+// because this is the only method of the 3 that has a *concept* of
+// "junk" <wink>.
+//
+// Timing:  Basic R-O is cubic time worst case and quadratic time expected
+// case.  SequenceMatcher is quadratic time for the worst case and has
+// expected-case behavior dependent in a complicated way on how many
+// elements the sequences have in common; best case time is linear.
+type SequenceMatcher struct {
+	a              []string
+	b              []string
+	b2j            map[string][]int
+	IsJunk         func(string) bool
+	autoJunk       bool
+	bJunk          map[string]struct{}
+	matchingBlocks []Match
+	fullBCount     map[string]int
+	bPopular       map[string]struct{}
+	opCodes        []OpCode
+}
+
+func NewMatcher(a, b []string) *SequenceMatcher {
+	m := SequenceMatcher{autoJunk: true}
+	m.SetSeqs(a, b)
+	return &m
+}
+
+func NewMatcherWithJunk(a, b []string, autoJunk bool,
+	isJunk func(string) bool) *SequenceMatcher {
+
+	m := SequenceMatcher{IsJunk: isJunk, autoJunk: autoJunk}
+	m.SetSeqs(a, b)
+	return &m
+}
+
+// Set two sequences to be compared.
+func (m *SequenceMatcher) SetSeqs(a, b []string) {
+	m.SetSeq1(a)
+	m.SetSeq2(b)
+}
+
+// Set the first sequence to be compared. The second sequence to be compared is
+// not changed.
+//
+// SequenceMatcher computes and caches detailed information about the second
+// sequence, so if you want to compare one sequence S against many sequences,
+// use .SetSeq2(s) once and call .SetSeq1(x) repeatedly for each of the other
+// sequences.
+//
+// See also SetSeqs() and SetSeq2().
+func (m *SequenceMatcher) SetSeq1(a []string) {
+	if &a == &m.a {
+		return
+	}
+	m.a = a
+	m.matchingBlocks = nil
+	m.opCodes = nil
+}
+
+// Set the second sequence to be compared. The first sequence to be compared is
+// not changed.
+func (m *SequenceMatcher) SetSeq2(b []string) {
+	if &b == &m.b {
+		return
+	}
+	m.b = b
+	m.matchingBlocks = nil
+	m.opCodes = nil
+	m.fullBCount = nil
+	m.chainB()
+}
+
+func (m *SequenceMatcher) chainB() {
+	// Populate line -> index mapping
+	b2j := map[string][]int{}
+	for i, s := range m.b {
+		indices := b2j[s]
+		indices = append(indices, i)
+		b2j[s] = indices
+	}
+
+	// Purge junk elements
+	m.bJunk = map[string]struct{}{}
+	if m.IsJunk != nil {
+		junk := m.bJunk
+		for s, _ := range b2j {
+			if m.IsJunk(s) {
+				junk[s] = struct{}{}
+			}
+		}
+		for s, _ := range junk {
+			delete(b2j, s)
+		}
+	}
+
+	// Purge remaining popular elements
+	popular := map[string]struct{}{}
+	n := len(m.b)
+	if m.autoJunk && n >= 200 {
+		ntest := n/100 + 1
+		for s, indices := range b2j {
+			if len(indices) > ntest {
+				popular[s] = struct{}{}
+			}
+		}
+		for s, _ := range popular {
+			delete(b2j, s)
+		}
+	}
+	m.bPopular = popular
+	m.b2j = b2j
+}
+
+func (m *SequenceMatcher) isBJunk(s string) bool {
+	_, ok := m.bJunk[s]
+	return ok
+}
+
+// Find longest matching block in a[alo:ahi] and b[blo:bhi].
+//
+// If IsJunk is not defined:
+//
+// Return (i,j,k) such that a[i:i+k] is equal to b[j:j+k], where
+//     alo <= i <= i+k <= ahi
+//     blo <= j <= j+k <= bhi
+// and for all (i',j',k') meeting those conditions,
+//     k >= k'
+//     i <= i'
+//     and if i == i', j <= j'
+//
+// In other words, of all maximal matching blocks, return one that
+// starts earliest in a, and of all those maximal matching blocks that
+// start earliest in a, return the one that starts earliest in b.
+//
+// If IsJunk is defined, first the longest matching block is
+// determined as above, but with the additional restriction that no
+// junk element appears in the block.  Then that block is extended as
+// far as possible by matching (only) junk elements on both sides.  So
+// the resulting block never matches on junk except as identical junk
+// happens to be adjacent to an "interesting" match.
+//
+// If no blocks match, return (alo, blo, 0).
+func (m *SequenceMatcher) findLongestMatch(alo, ahi, blo, bhi int) Match {
+	// CAUTION:  stripping common prefix or suffix would be incorrect.
+	// E.g.,
+	//    ab
+	//    acab
+	// Longest matching block is "ab", but if common prefix is
+	// stripped, it's "a" (tied with "b").  UNIX(tm) diff does so
+	// strip, so ends up claiming that ab is changed to acab by
+	// inserting "ca" in the middle.  That's minimal but unintuitive:
+	// "it's obvious" that someone inserted "ac" at the front.
+	// Windiff ends up at the same place as diff, but by pairing up
+	// the unique 'b's and then matching the first two 'a's.
+	besti, bestj, bestsize := alo, blo, 0
+
+	// find longest junk-free match
+	// during an iteration of the loop, j2len[j] = length of longest
+	// junk-free match ending with a[i-1] and b[j]
+	j2len := map[int]int{}
+	for i := alo; i != ahi; i++ {
+		// look at all instances of a[i] in b; note that because
+		// b2j has no junk keys, the loop is skipped if a[i] is junk
+		newj2len := map[int]int{}
+		for _, j := range m.b2j[m.a[i]] {
+			// a[i] matches b[j]
+			if j < blo {
+				continue
+			}
+			if j >= bhi {
+				break
+			}
+			k := j2len[j-1] + 1
+			newj2len[j] = k
+			if k > bestsize {
+				besti, bestj, bestsize = i-k+1, j-k+1, k
+			}
+		}
+		j2len = newj2len
+	}
+
+	// Extend the best by non-junk elements on each end.  In particular,
+	// "popular" non-junk elements aren't in b2j, which greatly speeds
+	// the inner loop above, but also means "the best" match so far
+	// doesn't contain any junk *or* popular non-junk elements.
+	for besti > alo && bestj > blo && !m.isBJunk(m.b[bestj-1]) &&
+		m.a[besti-1] == m.b[bestj-1] {
+		besti, bestj, bestsize = besti-1, bestj-1, bestsize+1
+	}
+	for besti+bestsize < ahi && bestj+bestsize < bhi &&
+		!m.isBJunk(m.b[bestj+bestsize]) &&
+		m.a[besti+bestsize] == m.b[bestj+bestsize] {
+		bestsize += 1
+	}
+
+	// Now that we have a wholly interesting match (albeit possibly
+	// empty!), we may as well suck up the matching junk on each
+	// side of it too.  Can't think of a good reason not to, and it
+	// saves post-processing the (possibly considerable) expense of
+	// figuring out what to do with it.  In the case of an empty
+	// interesting match, this is clearly the right thing to do,
+	// because no other kind of match is possible in the regions.
+	for besti > alo && bestj > blo && m.isBJunk(m.b[bestj-1]) &&
+		m.a[besti-1] == m.b[bestj-1] {
+		besti, bestj, bestsize = besti-1, bestj-1, bestsize+1
+	}
+	for besti+bestsize < ahi && bestj+bestsize < bhi &&
+		m.isBJunk(m.b[bestj+bestsize]) &&
+		m.a[besti+bestsize] == m.b[bestj+bestsize] {
+		bestsize += 1
+	}
+
+	return Match{A: besti, B: bestj, Size: bestsize}
+}
+
+// Return list of triples describing matching subsequences.
+//
+// Each triple is of the form (i, j, n), and means that
+// a[i:i+n] == b[j:j+n].  The triples are monotonically increasing in
+// i and in j. It's also guaranteed that if (i, j, n) and (i', j', n') are
+// adjacent triples in the list, and the second is not the last triple in the
+// list, then i+n != i' or j+n != j'. IOW, adjacent triples never describe
+// adjacent equal blocks.
+//
+// The last triple is a dummy, (len(a), len(b), 0), and is the only
+// triple with n==0.
+func (m *SequenceMatcher) GetMatchingBlocks() []Match {
+	if m.matchingBlocks != nil {
+		return m.matchingBlocks
+	}
+
+	var matchBlocks func(alo, ahi, blo, bhi int, matched []Match) []Match
+	matchBlocks = func(alo, ahi, blo, bhi int, matched []Match) []Match {
+		match := m.findLongestMatch(alo, ahi, blo, bhi)
+		i, j, k := match.A, match.B, match.Size
+		if match.Size > 0 {
+			if alo < i && blo < j {
+				matched = matchBlocks(alo, i, blo, j, matched)
+			}
+			matched = append(matched, match)
+			if i+k < ahi && j+k < bhi {
+				matched = matchBlocks(i+k, ahi, j+k, bhi, matched)
+			}
+		}
+		return matched
+	}
+	matched := matchBlocks(0, len(m.a), 0, len(m.b), nil)
+
+	// It's possible that we have adjacent equal blocks in the
+	// matching_blocks list now.
+	nonAdjacent := []Match{}
+	i1, j1, k1 := 0, 0, 0
+	for _, b := range matched {
+		// Is this block adjacent to i1, j1, k1?
+		i2, j2, k2 := b.A, b.B, b.Size
+		if i1+k1 == i2 && j1+k1 == j2 {
+			// Yes, so collapse them -- this just increases the length of
+			// the first block by the length of the second, and the first
+			// block so lengthened remains the block to compare against.
+			k1 += k2
+		} else {
+			// Not adjacent.  Remember the first block (k1==0 means it's
+			// the dummy we started with), and make the second block the
+			// new block to compare against.
+			if k1 > 0 {
+				nonAdjacent = append(nonAdjacent, Match{i1, j1, k1})
+			}
+			i1, j1, k1 = i2, j2, k2
+		}
+	}
+	if k1 > 0 {
+		nonAdjacent = append(nonAdjacent, Match{i1, j1, k1})
+	}
+
+	nonAdjacent = append(nonAdjacent, Match{len(m.a), len(m.b), 0})
+	m.matchingBlocks = nonAdjacent
+	return m.matchingBlocks
+}
+
+// Return list of 5-tuples describing how to turn a into b.
+//
+// Each tuple is of the form (tag, i1, i2, j1, j2).  The first tuple
+// has i1 == j1 == 0, and remaining tuples have i1 == the i2 from the
+// tuple preceding it, and likewise for j1 == the previous j2.
+//
+// The tags are characters, with these meanings:
+//
+// 'r' (replace):  a[i1:i2] should be replaced by b[j1:j2]
+//
+// 'd' (delete):   a[i1:i2] should be deleted, j1==j2 in this case.
+//
+// 'i' (insert):   b[j1:j2] should be inserted at a[i1:i1], i1==i2 in this case.
+//
+// 'e' (equal):    a[i1:i2] == b[j1:j2]
+func (m *SequenceMatcher) GetOpCodes() []OpCode {
+	if m.opCodes != nil {
+		return m.opCodes
+	}
+	i, j := 0, 0
+	matching := m.GetMatchingBlocks()
+	opCodes := make([]OpCode, 0, len(matching))
+	for _, m := range matching {
+		//  invariant:  we've pumped out correct diffs to change
+		//  a[:i] into b[:j], and the next matching block is
+		//  a[ai:ai+size] == b[bj:bj+size]. So we need to pump
+		//  out a diff to change a[i:ai] into b[j:bj], pump out
+		//  the matching block, and move (i,j) beyond the match
+		ai, bj, size := m.A, m.B, m.Size
+		tag := byte(0)
+		if i < ai && j < bj {
+			tag = 'r'
+		} else if i < ai {
+			tag = 'd'
+		} else if j < bj {
+			tag = 'i'
+		}
+		if tag > 0 {
+			opCodes = append(opCodes, OpCode{tag, i, ai, j, bj})
+		}
+		i, j = ai+size, bj+size
+		// the list of matching blocks is terminated by a
+		// sentinel with size 0
+		if size > 0 {
+			opCodes = append(opCodes, OpCode{'e', ai, i, bj, j})
+		}
+	}
+	m.opCodes = opCodes
+	return m.opCodes
+}
+
+// Isolate change clusters by eliminating ranges with no changes.
+//
+// Return a generator of groups with up to n lines of context.
+// Each group is in the same format as returned by GetOpCodes().
+func (m *SequenceMatcher) GetGroupedOpCodes(n int) [][]OpCode {
+	if n < 0 {
+		n = 3
+	}
+	codes := m.GetOpCodes()
+	if len(codes) == 0 {
+		codes = []OpCode{OpCode{'e', 0, 1, 0, 1}}
+	}
+	// Fixup leading and trailing groups if they show no changes.
+	if codes[0].Tag == 'e' {
+		c := codes[0]
+		i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
+		codes[0] = OpCode{c.Tag, max(i1, i2-n), i2, max(j1, j2-n), j2}
+	}
+	if codes[len(codes)-1].Tag == 'e' {
+		c := codes[len(codes)-1]
+		i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
+		codes[len(codes)-1] = OpCode{c.Tag, i1, min(i2, i1+n), j1, min(j2, j1+n)}
+	}
+	nn := n + n
+	groups := [][]OpCode{}
+	group := []OpCode{}
+	for _, c := range codes {
+		i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
+		// End the current group and start a new one whenever
+		// there is a large range with no changes.
+		if c.Tag == 'e' && i2-i1 > nn {
+			group = append(group, OpCode{c.Tag, i1, min(i2, i1+n),
+				j1, min(j2, j1+n)})
+			groups = append(groups, group)
+			group = []OpCode{}
+			i1, j1 = max(i1, i2-n), max(j1, j2-n)
+		}
+		group = append(group, OpCode{c.Tag, i1, i2, j1, j2})
+	}
+	if len(group) > 0 && !(len(group) == 1 && group[0].Tag == 'e') {
+		groups = append(groups, group)
+	}
+	return groups
+}
+
+// Return a measure of the sequences' similarity (float in [0,1]).
+//
+// Where T is the total number of elements in both sequences, and
+// M is the number of matches, this is 2.0*M / T.
+// Note that this is 1 if the sequences are identical, and 0 if
+// they have nothing in common.
+//
+// .Ratio() is expensive to compute if you haven't already computed
+// .GetMatchingBlocks() or .GetOpCodes(), in which case you may
+// want to try .QuickRatio() or .RealQuickRation() first to get an
+// upper bound.
+func (m *SequenceMatcher) Ratio() float64 {
+	matches := 0
+	for _, m := range m.GetMatchingBlocks() {
+		matches += m.Size
+	}
+	return calculateRatio(matches, len(m.a)+len(m.b))
+}
+
+// Return an upper bound on ratio() relatively quickly.
+//
+// This isn't defined beyond that it is an upper bound on .Ratio(), and
+// is faster to compute.
+func (m *SequenceMatcher) QuickRatio() float64 {
+	// viewing a and b as multisets, set matches to the cardinality
+	// of their intersection; this counts the number of matches
+	// without regard to order, so is clearly an upper bound
+	if m.fullBCount == nil {
+		m.fullBCount = map[string]int{}
+		for _, s := range m.b {
+			m.fullBCount[s] = m.fullBCount[s] + 1
+		}
+	}
+
+	// avail[x] is the number of times x appears in 'b' less the
+	// number of times we've seen it in 'a' so far ... kinda
+	avail := map[string]int{}
+	matches := 0
+	for _, s := range m.a {
+		n, ok := avail[s]
+		if !ok {
+			n = m.fullBCount[s]
+		}
+		avail[s] = n - 1
+		if n > 0 {
+			matches += 1
+		}
+	}
+	return calculateRatio(matches, len(m.a)+len(m.b))
+}
+
+// Return an upper bound on ratio() very quickly.
+//
+// This isn't defined beyond that it is an upper bound on .Ratio(), and
+// is faster to compute than either .Ratio() or .QuickRatio().
+func (m *SequenceMatcher) RealQuickRatio() float64 {
+	la, lb := len(m.a), len(m.b)
+	return calculateRatio(min(la, lb), la+lb)
+}
+
+// Convert range to the "ed" format
+func formatRangeUnified(start, stop int) string {
+	// Per the diff spec at http://www.unix.org/single_unix_specification/
+	beginning := start + 1 // lines start numbering with one
+	length := stop - start
+	if length == 1 {
+		return fmt.Sprintf("%d", beginning)
+	}
+	if length == 0 {
+		beginning -= 1 // empty ranges begin at line just before the range
+	}
+	return fmt.Sprintf("%d,%d", beginning, length)
+}
+
+// Unified diff parameters
+type UnifiedDiff struct {
+	A        []string // First sequence lines
+	FromFile string   // First file name
+	FromDate string   // First file time
+	B        []string // Second sequence lines
+	ToFile   string   // Second file name
+	ToDate   string   // Second file time
+	Eol      string   // Headers end of line, defaults to LF
+	Context  int      // Number of context lines
+}
+
+// Compare two sequences of lines; generate the delta as a unified diff.
+//
+// Unified diffs are a compact way of showing line changes and a few
+// lines of context.  The number of context lines is set by 'n' which
+// defaults to three.
+//
+// By default, the diff control lines (those with ---, +++, or @@) are
+// created with a trailing newline.  This is helpful so that inputs
+// created from file.readlines() result in diffs that are suitable for
+// file.writelines() since both the inputs and outputs have trailing
+// newlines.
+//
+// For inputs that do not have trailing newlines, set the lineterm
+// argument to "" so that the output will be uniformly newline free.
+//
+// The unidiff format normally has a header for filenames and modification
+// times.  Any or all of these may be specified using strings for
+// 'fromfile', 'tofile', 'fromfiledate', and 'tofiledate'.
+// The modification times are normally expressed in the ISO 8601 format.
+func WriteUnifiedDiff(writer io.Writer, diff UnifiedDiff) error {
+	buf := bufio.NewWriter(writer)
+	defer buf.Flush()
+	wf := func(format string, args ...interface{}) error {
+		_, err := buf.WriteString(fmt.Sprintf(format, args...))
+		return err
+	}
+	ws := func(s string) error {
+		_, err := buf.WriteString(s)
+		return err
+	}
+
+	if len(diff.Eol) == 0 {
+		diff.Eol = "\n"
+	}
+
+	started := false
+	m := NewMatcher(diff.A, diff.B)
+	for _, g := range m.GetGroupedOpCodes(diff.Context) {
+		if !started {
+			started = true
+			fromDate := ""
+			if len(diff.FromDate) > 0 {
+				fromDate = "\t" + diff.FromDate
+			}
+			toDate := ""
+			if len(diff.ToDate) > 0 {
+				toDate = "\t" + diff.ToDate
+			}
+			if diff.FromFile != "" || diff.ToFile != "" {
+				err := wf("--- %s%s%s", diff.FromFile, fromDate, diff.Eol)
+				if err != nil {
+					return err
+				}
+				err = wf("+++ %s%s%s", diff.ToFile, toDate, diff.Eol)
+				if err != nil {
+					return err
+				}
+			}
+		}
+		first, last := g[0], g[len(g)-1]
+		range1 := formatRangeUnified(first.I1, last.I2)
+		range2 := formatRangeUnified(first.J1, last.J2)
+		if err := wf("@@ -%s +%s @@%s", range1, range2, diff.Eol); err != nil {
+			return err
+		}
+		for _, c := range g {
+			i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
+			if c.Tag == 'e' {
+				for _, line := range diff.A[i1:i2] {
+					if err := ws(" " + line); err != nil {
+						return err
+					}
+				}
+				continue
+			}
+			if c.Tag == 'r' || c.Tag == 'd' {
+				for _, line := range diff.A[i1:i2] {
+					if err := ws("-" + line); err != nil {
+						return err
+					}
+				}
+			}
+			if c.Tag == 'r' || c.Tag == 'i' {
+				for _, line := range diff.B[j1:j2] {
+					if err := ws("+" + line); err != nil {
+						return err
+					}
+				}
+			}
+		}
+	}
+	return nil
+}
+
+// Like WriteUnifiedDiff but returns the diff a string.
+func GetUnifiedDiffString(diff UnifiedDiff) (string, error) {
+	w := &bytes.Buffer{}
+	err := WriteUnifiedDiff(w, diff)
+	return string(w.Bytes()), err
+}
+
+// Convert range to the "ed" format.
+func formatRangeContext(start, stop int) string {
+	// Per the diff spec at http://www.unix.org/single_unix_specification/
+	beginning := start + 1 // lines start numbering with one
+	length := stop - start
+	if length == 0 {
+		beginning -= 1 // empty ranges begin at line just before the range
+	}
+	if length <= 1 {
+		return fmt.Sprintf("%d", beginning)
+	}
+	return fmt.Sprintf("%d,%d", beginning, beginning+length-1)
+}
+
+type ContextDiff UnifiedDiff
+
+// Compare two sequences of lines; generate the delta as a context diff.
+//
+// Context diffs are a compact way of showing line changes and a few
+// lines of context. The number of context lines is set by diff.Context
+// which defaults to three.
+//
+// By default, the diff control lines (those with *** or ---) are
+// created with a trailing newline.
+//
+// For inputs that do not have trailing newlines, set the diff.Eol
+// argument to "" so that the output will be uniformly newline free.
+//
+// The context diff format normally has a header for filenames and
+// modification times.  Any or all of these may be specified using
+// strings for diff.FromFile, diff.ToFile, diff.FromDate, diff.ToDate.
+// The modification times are normally expressed in the ISO 8601 format.
+// If not specified, the strings default to blanks.
+func WriteContextDiff(writer io.Writer, diff ContextDiff) error {
+	buf := bufio.NewWriter(writer)
+	defer buf.Flush()
+	var diffErr error
+	wf := func(format string, args ...interface{}) {
+		_, err := buf.WriteString(fmt.Sprintf(format, args...))
+		if diffErr == nil && err != nil {
+			diffErr = err
+		}
+	}
+	ws := func(s string) {
+		_, err := buf.WriteString(s)
+		if diffErr == nil && err != nil {
+			diffErr = err
+		}
+	}
+
+	if len(diff.Eol) == 0 {
+		diff.Eol = "\n"
+	}
+
+	prefix := map[byte]string{
+		'i': "+ ",
+		'd': "- ",
+		'r': "! ",
+		'e': "  ",
+	}
+
+	started := false
+	m := NewMatcher(diff.A, diff.B)
+	for _, g := range m.GetGroupedOpCodes(diff.Context) {
+		if !started {
+			started = true
+			fromDate := ""
+			if len(diff.FromDate) > 0 {
+				fromDate = "\t" + diff.FromDate
+			}
+			toDate := ""
+			if len(diff.ToDate) > 0 {
+				toDate = "\t" + diff.ToDate
+			}
+			if diff.FromFile != "" || diff.ToFile != "" {
+				wf("*** %s%s%s", diff.FromFile, fromDate, diff.Eol)
+				wf("--- %s%s%s", diff.ToFile, toDate, diff.Eol)
+			}
+		}
+
+		first, last := g[0], g[len(g)-1]
+		ws("***************" + diff.Eol)
+
+		range1 := formatRangeContext(first.I1, last.I2)
+		wf("*** %s ****%s", range1, diff.Eol)
+		for _, c := range g {
+			if c.Tag == 'r' || c.Tag == 'd' {
+				for _, cc := range g {
+					if cc.Tag == 'i' {
+						continue
+					}
+					for _, line := range diff.A[cc.I1:cc.I2] {
+						ws(prefix[cc.Tag] + line)
+					}
+				}
+				break
+			}
+		}
+
+		range2 := formatRangeContext(first.J1, last.J2)
+		wf("--- %s ----%s", range2, diff.Eol)
+		for _, c := range g {
+			if c.Tag == 'r' || c.Tag == 'i' {
+				for _, cc := range g {
+					if cc.Tag == 'd' {
+						continue
+					}
+					for _, line := range diff.B[cc.J1:cc.J2] {
+						ws(prefix[cc.Tag] + line)
+					}
+				}
+				break
+			}
+		}
+	}
+	return diffErr
+}
+
+// Like WriteContextDiff but returns the diff a string.
+func GetContextDiffString(diff ContextDiff) (string, error) {
+	w := &bytes.Buffer{}
+	err := WriteContextDiff(w, diff)
+	return string(w.Bytes()), err
+}
+
+// Split a string on "\n" while preserving them. The output can be used
+// as input for UnifiedDiff and ContextDiff structures.
+func SplitLines(s string) []string {
+	lines := strings.SplitAfter(s, "\n")
+	lines[len(lines)-1] += "\n"
+	return lines
+}

vendor/github.com/stretchr/testify/LICENCE.txt

@@ -0,0 +1,22 @@
+Copyright (c) 2012 - 2013 Mat Ryer and Tyler Bunnell
+
+Please consider promoting this project if you find it useful.
+
+Permission is hereby granted, free of charge, to any person 
+obtaining a copy of this software and associated documentation 
+files (the "Software"), to deal in the Software without restriction, 
+including without limitation the rights to use, copy, modify, merge, 
+publish, distribute, sublicense, and/or sell copies of the Software, 
+and to permit persons to whom the Software is furnished to do so, 
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES 
+OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT 
+OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE 
+OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/stretchr/testify/LICENSE

@@ -0,0 +1,22 @@
+Copyright (c) 2012 - 2013 Mat Ryer and Tyler Bunnell
+
+Please consider promoting this project if you find it useful.
+
+Permission is hereby granted, free of charge, to any person 
+obtaining a copy of this software and associated documentation 
+files (the "Software"), to deal in the Software without restriction, 
+including without limitation the rights to use, copy, modify, merge, 
+publish, distribute, sublicense, and/or sell copies of the Software, 
+and to permit persons to whom the Software is furnished to do so, 
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES 
+OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT 
+OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE 
+OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/stretchr/testify/assert/assertion_forward.go

@@ -0,0 +1,352 @@
+/*
+* CODE GENERATED AUTOMATICALLY WITH github.com/stretchr/testify/_codegen
+* THIS FILE MUST NOT BE EDITED BY HAND
+ */
+
+package assert
+
+import (
+	http "net/http"
+	url "net/url"
+	time "time"
+)
+
+// Condition uses a Comparison to assert a complex condition.
+func (a *Assertions) Condition(comp Comparison, msgAndArgs ...interface{}) bool {
+	return Condition(a.t, comp, msgAndArgs...)
+}
+
+// Contains asserts that the specified string, list(array, slice...) or map contains the
+// specified substring or element.
+//
+//    a.Contains("Hello World", "World", "But 'Hello World' does contain 'World'")
+//    a.Contains(["Hello", "World"], "World", "But ["Hello", "World"] does contain 'World'")
+//    a.Contains({"Hello": "World"}, "Hello", "But {'Hello': 'World'} does contain 'Hello'")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) Contains(s interface{}, contains interface{}, msgAndArgs ...interface{}) bool {
+	return Contains(a.t, s, contains, msgAndArgs...)
+}
+
+// Empty asserts that the specified object is empty.  I.e. nil, "", false, 0 or either
+// a slice or a channel with len == 0.
+//
+//  a.Empty(obj)
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) Empty(object interface{}, msgAndArgs ...interface{}) bool {
+	return Empty(a.t, object, msgAndArgs...)
+}
+
+// Equal asserts that two objects are equal.
+//
+//    a.Equal(123, 123, "123 and 123 should be equal")
+//
+// Returns whether the assertion was successful (true) or not (false).
+//
+// Pointer variable equality is determined based on the equality of the
+// referenced values (as opposed to the memory addresses).
+func (a *Assertions) Equal(expected interface{}, actual interface{}, msgAndArgs ...interface{}) bool {
+	return Equal(a.t, expected, actual, msgAndArgs...)
+}
+
+// EqualError asserts that a function returned an error (i.e. not `nil`)
+// and that it is equal to the provided error.
+//
+//   actualObj, err := SomeFunction()
+//   a.EqualError(err,  expectedErrorString, "An error was expected")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) EqualError(theError error, errString string, msgAndArgs ...interface{}) bool {
+	return EqualError(a.t, theError, errString, msgAndArgs...)
+}
+
+// EqualValues asserts that two objects are equal or convertable to the same types
+// and equal.
+//
+//    a.EqualValues(uint32(123), int32(123), "123 and 123 should be equal")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) EqualValues(expected interface{}, actual interface{}, msgAndArgs ...interface{}) bool {
+	return EqualValues(a.t, expected, actual, msgAndArgs...)
+}
+
+// Error asserts that a function returned an error (i.e. not `nil`).
+//
+//   actualObj, err := SomeFunction()
+//   if a.Error(err, "An error was expected") {
+// 	   assert.Equal(t, err, expectedError)
+//   }
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) Error(err error, msgAndArgs ...interface{}) bool {
+	return Error(a.t, err, msgAndArgs...)
+}
+
+// Exactly asserts that two objects are equal is value and type.
+//
+//    a.Exactly(int32(123), int64(123), "123 and 123 should NOT be equal")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) Exactly(expected interface{}, actual interface{}, msgAndArgs ...interface{}) bool {
+	return Exactly(a.t, expected, actual, msgAndArgs...)
+}
+
+// Fail reports a failure through
+func (a *Assertions) Fail(failureMessage string, msgAndArgs ...interface{}) bool {
+	return Fail(a.t, failureMessage, msgAndArgs...)
+}
+
+// FailNow fails test
+func (a *Assertions) FailNow(failureMessage string, msgAndArgs ...interface{}) bool {
+	return FailNow(a.t, failureMessage, msgAndArgs...)
+}
+
+// False asserts that the specified value is false.
+//
+//    a.False(myBool, "myBool should be false")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) False(value bool, msgAndArgs ...interface{}) bool {
+	return False(a.t, value, msgAndArgs...)
+}
+
+// HTTPBodyContains asserts that a specified handler returns a
+// body that contains a string.
+//
+//  a.HTTPBodyContains(myHandler, "www.google.com", nil, "I'm Feeling Lucky")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) HTTPBodyContains(handler http.HandlerFunc, method string, url string, values url.Values, str interface{}) bool {
+	return HTTPBodyContains(a.t, handler, method, url, values, str)
+}
+
+// HTTPBodyNotContains asserts that a specified handler returns a
+// body that does not contain a string.
+//
+//  a.HTTPBodyNotContains(myHandler, "www.google.com", nil, "I'm Feeling Lucky")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) HTTPBodyNotContains(handler http.HandlerFunc, method string, url string, values url.Values, str interface{}) bool {
+	return HTTPBodyNotContains(a.t, handler, method, url, values, str)
+}
+
+// HTTPError asserts that a specified handler returns an error status code.
+//
+//  a.HTTPError(myHandler, "POST", "/a/b/c", url.Values{"a": []string{"b", "c"}}
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) HTTPError(handler http.HandlerFunc, method string, url string, values url.Values) bool {
+	return HTTPError(a.t, handler, method, url, values)
+}
+
+// HTTPRedirect asserts that a specified handler returns a redirect status code.
+//
+//  a.HTTPRedirect(myHandler, "GET", "/a/b/c", url.Values{"a": []string{"b", "c"}}
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) HTTPRedirect(handler http.HandlerFunc, method string, url string, values url.Values) bool {
+	return HTTPRedirect(a.t, handler, method, url, values)
+}
+
+// HTTPSuccess asserts that a specified handler returns a success status code.
+//
+//  a.HTTPSuccess(myHandler, "POST", "http://www.google.com", nil)
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) HTTPSuccess(handler http.HandlerFunc, method string, url string, values url.Values) bool {
+	return HTTPSuccess(a.t, handler, method, url, values)
+}
+
+// Implements asserts that an object is implemented by the specified interface.
+//
+//    a.Implements((*MyInterface)(nil), new(MyObject), "MyObject")
+func (a *Assertions) Implements(interfaceObject interface{}, object interface{}, msgAndArgs ...interface{}) bool {
+	return Implements(a.t, interfaceObject, object, msgAndArgs...)
+}
+
+// InDelta asserts that the two numerals are within delta of each other.
+//
+// 	 a.InDelta(math.Pi, (22 / 7.0), 0.01)
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) InDelta(expected interface{}, actual interface{}, delta float64, msgAndArgs ...interface{}) bool {
+	return InDelta(a.t, expected, actual, delta, msgAndArgs...)
+}
+
+// InDeltaSlice is the same as InDelta, except it compares two slices.
+func (a *Assertions) InDeltaSlice(expected interface{}, actual interface{}, delta float64, msgAndArgs ...interface{}) bool {
+	return InDeltaSlice(a.t, expected, actual, delta, msgAndArgs...)
+}
+
+// InEpsilon asserts that expected and actual have a relative error less than epsilon
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) InEpsilon(expected interface{}, actual interface{}, epsilon float64, msgAndArgs ...interface{}) bool {
+	return InEpsilon(a.t, expected, actual, epsilon, msgAndArgs...)
+}
+
+// InEpsilonSlice is the same as InEpsilon, except it compares each value from two slices.
+func (a *Assertions) InEpsilonSlice(expected interface{}, actual interface{}, epsilon float64, msgAndArgs ...interface{}) bool {
+	return InEpsilonSlice(a.t, expected, actual, epsilon, msgAndArgs...)
+}
+
+// IsType asserts that the specified objects are of the same type.
+func (a *Assertions) IsType(expectedType interface{}, object interface{}, msgAndArgs ...interface{}) bool {
+	return IsType(a.t, expectedType, object, msgAndArgs...)
+}
+
+// JSONEq asserts that two JSON strings are equivalent.
+//
+//  a.JSONEq(`{"hello": "world", "foo": "bar"}`, `{"foo": "bar", "hello": "world"}`)
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) JSONEq(expected string, actual string, msgAndArgs ...interface{}) bool {
+	return JSONEq(a.t, expected, actual, msgAndArgs...)
+}
+
+// Len asserts that the specified object has specific length.
+// Len also fails if the object has a type that len() not accept.
+//
+//    a.Len(mySlice, 3, "The size of slice is not 3")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) Len(object interface{}, length int, msgAndArgs ...interface{}) bool {
+	return Len(a.t, object, length, msgAndArgs...)
+}
+
+// Nil asserts that the specified object is nil.
+//
+//    a.Nil(err, "err should be nothing")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) Nil(object interface{}, msgAndArgs ...interface{}) bool {
+	return Nil(a.t, object, msgAndArgs...)
+}
+
+// NoError asserts that a function returned no error (i.e. `nil`).
+//
+//   actualObj, err := SomeFunction()
+//   if a.NoError(err) {
+// 	   assert.Equal(t, actualObj, expectedObj)
+//   }
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) NoError(err error, msgAndArgs ...interface{}) bool {
+	return NoError(a.t, err, msgAndArgs...)
+}
+
+// NotContains asserts that the specified string, list(array, slice...) or map does NOT contain the
+// specified substring or element.
+//
+//    a.NotContains("Hello World", "Earth", "But 'Hello World' does NOT contain 'Earth'")
+//    a.NotContains(["Hello", "World"], "Earth", "But ['Hello', 'World'] does NOT contain 'Earth'")
+//    a.NotContains({"Hello": "World"}, "Earth", "But {'Hello': 'World'} does NOT contain 'Earth'")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) NotContains(s interface{}, contains interface{}, msgAndArgs ...interface{}) bool {
+	return NotContains(a.t, s, contains, msgAndArgs...)
+}
+
+// NotEmpty asserts that the specified object is NOT empty.  I.e. not nil, "", false, 0 or either
+// a slice or a channel with len == 0.
+//
+//  if a.NotEmpty(obj) {
+//    assert.Equal(t, "two", obj[1])
+//  }
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) NotEmpty(object interface{}, msgAndArgs ...interface{}) bool {
+	return NotEmpty(a.t, object, msgAndArgs...)
+}
+
+// NotEqual asserts that the specified values are NOT equal.
+//
+//    a.NotEqual(obj1, obj2, "two objects shouldn't be equal")
+//
+// Returns whether the assertion was successful (true) or not (false).
+//
+// Pointer variable equality is determined based on the equality of the
+// referenced values (as opposed to the memory addresses).
+func (a *Assertions) NotEqual(expected interface{}, actual interface{}, msgAndArgs ...interface{}) bool {
+	return NotEqual(a.t, expected, actual, msgAndArgs...)
+}
+
+// NotNil asserts that the specified object is not nil.
+//
+//    a.NotNil(err, "err should be something")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) NotNil(object interface{}, msgAndArgs ...interface{}) bool {
+	return NotNil(a.t, object, msgAndArgs...)
+}
+
+// NotPanics asserts that the code inside the specified PanicTestFunc does NOT panic.
+//
+//   a.NotPanics(func(){
+//     RemainCalm()
+//   }, "Calling RemainCalm() should NOT panic")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) NotPanics(f PanicTestFunc, msgAndArgs ...interface{}) bool {
+	return NotPanics(a.t, f, msgAndArgs...)
+}
+
+// NotRegexp asserts that a specified regexp does not match a string.
+//
+//  a.NotRegexp(regexp.MustCompile("starts"), "it's starting")
+//  a.NotRegexp("^start", "it's not starting")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) NotRegexp(rx interface{}, str interface{}, msgAndArgs ...interface{}) bool {
+	return NotRegexp(a.t, rx, str, msgAndArgs...)
+}
+
+// NotZero asserts that i is not the zero value for its type and returns the truth.
+func (a *Assertions) NotZero(i interface{}, msgAndArgs ...interface{}) bool {
+	return NotZero(a.t, i, msgAndArgs...)
+}
+
+// Panics asserts that the code inside the specified PanicTestFunc panics.
+//
+//   a.Panics(func(){
+//     GoCrazy()
+//   }, "Calling GoCrazy() should panic")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) Panics(f PanicTestFunc, msgAndArgs ...interface{}) bool {
+	return Panics(a.t, f, msgAndArgs...)
+}
+
+// Regexp asserts that a specified regexp matches a string.
+//
+//  a.Regexp(regexp.MustCompile("start"), "it's starting")
+//  a.Regexp("start...$", "it's not starting")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) Regexp(rx interface{}, str interface{}, msgAndArgs ...interface{}) bool {
+	return Regexp(a.t, rx, str, msgAndArgs...)
+}
+
+// True asserts that the specified value is true.
+//
+//    a.True(myBool, "myBool should be true")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) True(value bool, msgAndArgs ...interface{}) bool {
+	return True(a.t, value, msgAndArgs...)
+}
+
+// WithinDuration asserts that the two times are within duration delta of each other.
+//
+//   a.WithinDuration(time.Now(), time.Now(), 10*time.Second, "The difference should not be more than 10s")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func (a *Assertions) WithinDuration(expected time.Time, actual time.Time, delta time.Duration, msgAndArgs ...interface{}) bool {
+	return WithinDuration(a.t, expected, actual, delta, msgAndArgs...)
+}
+
+// Zero asserts that i is the zero value for its type and returns the truth.
+func (a *Assertions) Zero(i interface{}, msgAndArgs ...interface{}) bool {
+	return Zero(a.t, i, msgAndArgs...)
+}

vendor/github.com/stretchr/testify/assert/assertion_forward.go.tmpl

@@ -0,0 +1,4 @@
+{{.CommentWithoutT "a"}}
+func (a *Assertions) {{.DocInfo.Name}}({{.Params}}) bool {
+	return {{.DocInfo.Name}}(a.t, {{.ForwardedParams}})
+}

vendor/github.com/stretchr/testify/assert/assertions.go

@@ -0,0 +1,1069 @@
+package assert
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"math"
+	"reflect"
+	"regexp"
+	"runtime"
+	"strings"
+	"time"
+	"unicode"
+	"unicode/utf8"
+
+	"github.com/davecgh/go-spew/spew"
+	"github.com/pmezard/go-difflib/difflib"
+)
+
+// TestingT is an interface wrapper around *testing.T
+type TestingT interface {
+	Errorf(format string, args ...interface{})
+}
+
+// Comparison a custom function that returns true on success and false on failure
+type Comparison func() (success bool)
+
+/*
+	Helper functions
+*/
+
+// ObjectsAreEqual determines if two objects are considered equal.
+//
+// This function does no assertion of any kind.
+func ObjectsAreEqual(expected, actual interface{}) bool {
+
+	if expected == nil || actual == nil {
+		return expected == actual
+	}
+
+	return reflect.DeepEqual(expected, actual)
+
+}
+
+// ObjectsAreEqualValues gets whether two objects are equal, or if their
+// values are equal.
+func ObjectsAreEqualValues(expected, actual interface{}) bool {
+	if ObjectsAreEqual(expected, actual) {
+		return true
+	}
+
+	actualType := reflect.TypeOf(actual)
+	if actualType == nil {
+		return false
+	}
+	expectedValue := reflect.ValueOf(expected)
+	if expectedValue.IsValid() && expectedValue.Type().ConvertibleTo(actualType) {
+		// Attempt comparison after type conversion
+		return reflect.DeepEqual(expectedValue.Convert(actualType).Interface(), actual)
+	}
+
+	return false
+}
+
+/* CallerInfo is necessary because the assert functions use the testing object
+internally, causing it to print the file:line of the assert method, rather than where
+the problem actually occurred in calling code.*/
+
+// CallerInfo returns an array of strings containing the file and line number
+// of each stack frame leading from the current test to the assert call that
+// failed.
+func CallerInfo() []string {
+
+	pc := uintptr(0)
+	file := ""
+	line := 0
+	ok := false
+	name := ""
+
+	callers := []string{}
+	for i := 0; ; i++ {
+		pc, file, line, ok = runtime.Caller(i)
+		if !ok {
+			// The breaks below failed to terminate the loop, and we ran off the
+			// end of the call stack.
+			break
+		}
+
+		// This is a huge edge case, but it will panic if this is the case, see #180
+		if file == "<autogenerated>" {
+			break
+		}
+
+		f := runtime.FuncForPC(pc)
+		if f == nil {
+			break
+		}
+		name = f.Name()
+
+		// testing.tRunner is the standard library function that calls
+		// tests. Subtests are called directly by tRunner, without going through
+		// the Test/Benchmark/Example function that contains the t.Run calls, so
+		// with subtests we should break when we hit tRunner, without adding it
+		// to the list of callers.
+		if name == "testing.tRunner" {
+			break
+		}
+
+		parts := strings.Split(file, "/")
+		dir := parts[len(parts)-2]
+		file = parts[len(parts)-1]
+		if (dir != "assert" && dir != "mock" && dir != "require") || file == "mock_test.go" {
+			callers = append(callers, fmt.Sprintf("%s:%d", file, line))
+		}
+
+		// Drop the package
+		segments := strings.Split(name, ".")
+		name = segments[len(segments)-1]
+		if isTest(name, "Test") ||
+			isTest(name, "Benchmark") ||
+			isTest(name, "Example") {
+			break
+		}
+	}
+
+	return callers
+}
+
+// Stolen from the `go test` tool.
+// isTest tells whether name looks like a test (or benchmark, according to prefix).
+// It is a Test (say) if there is a character after Test that is not a lower-case letter.
+// We don't want TesticularCancer.
+func isTest(name, prefix string) bool {
+	if !strings.HasPrefix(name, prefix) {
+		return false
+	}
+	if len(name) == len(prefix) { // "Test" is ok
+		return true
+	}
+	rune, _ := utf8.DecodeRuneInString(name[len(prefix):])
+	return !unicode.IsLower(rune)
+}
+
+// getWhitespaceString returns a string that is long enough to overwrite the default
+// output from the go testing framework.
+func getWhitespaceString() string {
+
+	_, file, line, ok := runtime.Caller(1)
+	if !ok {
+		return ""
+	}
+	parts := strings.Split(file, "/")
+	file = parts[len(parts)-1]
+
+	return strings.Repeat(" ", len(fmt.Sprintf("%s:%d:        ", file, line)))
+
+}
+
+func messageFromMsgAndArgs(msgAndArgs ...interface{}) string {
+	if len(msgAndArgs) == 0 || msgAndArgs == nil {
+		return ""
+	}
+	if len(msgAndArgs) == 1 {
+		return msgAndArgs[0].(string)
+	}
+	if len(msgAndArgs) > 1 {
+		return fmt.Sprintf(msgAndArgs[0].(string), msgAndArgs[1:]...)
+	}
+	return ""
+}
+
+// Aligns the provided message so that all lines after the first line start at the same location as the first line.
+// Assumes that the first line starts at the correct location (after carriage return, tab, label, spacer and tab).
+// The longestLabelLen parameter specifies the length of the longest label in the output (required becaues this is the
+// basis on which the alignment occurs).
+func indentMessageLines(message string, longestLabelLen int) string {
+	outBuf := new(bytes.Buffer)
+
+	for i, scanner := 0, bufio.NewScanner(strings.NewReader(message)); scanner.Scan(); i++ {
+		// no need to align first line because it starts at the correct location (after the label)
+		if i != 0 {
+			// append alignLen+1 spaces to align with "{{longestLabel}}:" before adding tab
+			outBuf.WriteString("\n\r\t" + strings.Repeat(" ", longestLabelLen +1) + "\t")
+		}
+		outBuf.WriteString(scanner.Text())
+	}
+
+	return outBuf.String()
+}
+
+type failNower interface {
+	FailNow()
+}
+
+// FailNow fails test
+func FailNow(t TestingT, failureMessage string, msgAndArgs ...interface{}) bool {
+	Fail(t, failureMessage, msgAndArgs...)
+
+	// We cannot extend TestingT with FailNow() and
+	// maintain backwards compatibility, so we fallback
+	// to panicking when FailNow is not available in
+	// TestingT.
+	// See issue #263
+
+	if t, ok := t.(failNower); ok {
+		t.FailNow()
+	} else {
+		panic("test failed and t is missing `FailNow()`")
+	}
+	return false
+}
+
+// Fail reports a failure through
+func Fail(t TestingT, failureMessage string, msgAndArgs ...interface{}) bool {
+	content := []labeledContent{
+		{"Error Trace", strings.Join(CallerInfo(), "\n\r\t\t\t")},
+		{"Error", failureMessage},
+	}
+
+	message := messageFromMsgAndArgs(msgAndArgs...)
+	if len(message) > 0 {
+		content = append(content, labeledContent{"Messages", message})
+	}
+
+	t.Errorf("\r" + getWhitespaceString() + labeledOutput(content...))
+
+	return false
+}
+
+type labeledContent struct {
+	label string
+	content string
+}
+
+// labeledOutput returns a string consisting of the provided labeledContent. Each labeled output is appended in the following manner:
+//
+//   \r\t{{label}}:{{align_spaces}}\t{{content}}\n
+//
+// The initial carriage return is required to undo/erase any padding added by testing.T.Errorf. The "\t{{label}}:" is for the label.
+// If a label is shorter than the longest label provided, padding spaces are added to make all the labels match in length. Once this
+// alignment is achieved, "\t{{content}}\n" is added for the output.
+//
+// If the content of the labeledOutput contains line breaks, the subsequent lines are aligned so that they start at the same location as the first line.
+func labeledOutput(content ...labeledContent) string {
+	longestLabel := 0
+	for _, v := range content {
+		if len(v.label) > longestLabel {
+			longestLabel = len(v.label)
+		}
+	}
+	var output string
+	for _, v := range content {
+		output += "\r\t" + v.label + ":" + strings.Repeat(" ", longestLabel-len(v.label)) + "\t" + indentMessageLines(v.content, longestLabel) + "\n"
+	}
+	return output
+}
+
+// Implements asserts that an object is implemented by the specified interface.
+//
+//    assert.Implements(t, (*MyInterface)(nil), new(MyObject), "MyObject")
+func Implements(t TestingT, interfaceObject interface{}, object interface{}, msgAndArgs ...interface{}) bool {
+
+	interfaceType := reflect.TypeOf(interfaceObject).Elem()
+
+	if !reflect.TypeOf(object).Implements(interfaceType) {
+		return Fail(t, fmt.Sprintf("%T must implement %v", object, interfaceType), msgAndArgs...)
+	}
+
+	return true
+
+}
+
+// IsType asserts that the specified objects are of the same type.
+func IsType(t TestingT, expectedType interface{}, object interface{}, msgAndArgs ...interface{}) bool {
+
+	if !ObjectsAreEqual(reflect.TypeOf(object), reflect.TypeOf(expectedType)) {
+		return Fail(t, fmt.Sprintf("Object expected to be of type %v, but was %v", reflect.TypeOf(expectedType), reflect.TypeOf(object)), msgAndArgs...)
+	}
+
+	return true
+}
+
+// Equal asserts that two objects are equal.
+//
+//    assert.Equal(t, 123, 123, "123 and 123 should be equal")
+//
+// Returns whether the assertion was successful (true) or not (false).
+//
+// Pointer variable equality is determined based on the equality of the
+// referenced values (as opposed to the memory addresses).
+func Equal(t TestingT, expected, actual interface{}, msgAndArgs ...interface{}) bool {
+
+	if !ObjectsAreEqual(expected, actual) {
+		diff := diff(expected, actual)
+		expected, actual = formatUnequalValues(expected, actual)
+		return Fail(t, fmt.Sprintf("Not equal: \n"+
+			"expected: %s\n"+
+			"received: %s%s", expected, actual, diff), msgAndArgs...)
+	}
+
+	return true
+
+}
+
+// formatUnequalValues takes two values of arbitrary types and returns string
+// representations appropriate to be presented to the user.
+//
+// If the values are not of like type, the returned strings will be prefixed
+// with the type name, and the value will be enclosed in parenthesis similar
+// to a type conversion in the Go grammar.
+func formatUnequalValues(expected, actual interface{}) (e string, a string) {
+	if reflect.TypeOf(expected) != reflect.TypeOf(actual) {
+		return fmt.Sprintf("%T(%#v)", expected, expected),
+			fmt.Sprintf("%T(%#v)", actual, actual)
+	}
+
+	return fmt.Sprintf("%#v", expected),
+		fmt.Sprintf("%#v", actual)
+}
+
+// EqualValues asserts that two objects are equal or convertable to the same types
+// and equal.
+//
+//    assert.EqualValues(t, uint32(123), int32(123), "123 and 123 should be equal")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func EqualValues(t TestingT, expected, actual interface{}, msgAndArgs ...interface{}) bool {
+
+	if !ObjectsAreEqualValues(expected, actual) {
+		diff := diff(expected, actual)
+		expected, actual = formatUnequalValues(expected, actual)
+		return Fail(t, fmt.Sprintf("Not equal: \n"+
+			"expected: %s\n"+
+			"received: %s%s", expected, actual, diff), msgAndArgs...)
+	}
+
+	return true
+
+}
+
+// Exactly asserts that two objects are equal is value and type.
+//
+//    assert.Exactly(t, int32(123), int64(123), "123 and 123 should NOT be equal")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func Exactly(t TestingT, expected, actual interface{}, msgAndArgs ...interface{}) bool {
+
+	aType := reflect.TypeOf(expected)
+	bType := reflect.TypeOf(actual)
+
+	if aType != bType {
+		return Fail(t, fmt.Sprintf("Types expected to match exactly\n\r\t%v != %v", aType, bType), msgAndArgs...)
+	}
+
+	return Equal(t, expected, actual, msgAndArgs...)
+
+}
+
+// NotNil asserts that the specified object is not nil.
+//
+//    assert.NotNil(t, err, "err should be something")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func NotNil(t TestingT, object interface{}, msgAndArgs ...interface{}) bool {
+	if !isNil(object) {
+		return true
+	}
+	return Fail(t, "Expected value not to be nil.", msgAndArgs...)
+}
+
+// isNil checks if a specified object is nil or not, without Failing.
+func isNil(object interface{}) bool {
+	if object == nil {
+		return true
+	}
+
+	value := reflect.ValueOf(object)
+	kind := value.Kind()
+	if kind >= reflect.Chan && kind <= reflect.Slice && value.IsNil() {
+		return true
+	}
+
+	return false
+}
+
+// Nil asserts that the specified object is nil.
+//
+//    assert.Nil(t, err, "err should be nothing")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func Nil(t TestingT, object interface{}, msgAndArgs ...interface{}) bool {
+	if isNil(object) {
+		return true
+	}
+	return Fail(t, fmt.Sprintf("Expected nil, but got: %#v", object), msgAndArgs...)
+}
+
+var numericZeros = []interface{}{
+	int(0),
+	int8(0),
+	int16(0),
+	int32(0),
+	int64(0),
+	uint(0),
+	uint8(0),
+	uint16(0),
+	uint32(0),
+	uint64(0),
+	float32(0),
+	float64(0),
+}
+
+// isEmpty gets whether the specified object is considered empty or not.
+func isEmpty(object interface{}) bool {
+
+	if object == nil {
+		return true
+	} else if object == "" {
+		return true
+	} else if object == false {
+		return true
+	}
+
+	for _, v := range numericZeros {
+		if object == v {
+			return true
+		}
+	}
+
+	objValue := reflect.ValueOf(object)
+
+	switch objValue.Kind() {
+	case reflect.Map:
+		fallthrough
+	case reflect.Slice, reflect.Chan:
+		{
+			return (objValue.Len() == 0)
+		}
+	case reflect.Struct:
+		switch object.(type) {
+		case time.Time:
+			return object.(time.Time).IsZero()
+		}
+	case reflect.Ptr:
+		{
+			if objValue.IsNil() {
+				return true
+			}
+			switch object.(type) {
+			case *time.Time:
+				return object.(*time.Time).IsZero()
+			default:
+				return false
+			}
+		}
+	}
+	return false
+}
+
+// Empty asserts that the specified object is empty.  I.e. nil, "", false, 0 or either
+// a slice or a channel with len == 0.
+//
+//  assert.Empty(t, obj)
+//
+// Returns whether the assertion was successful (true) or not (false).
+func Empty(t TestingT, object interface{}, msgAndArgs ...interface{}) bool {
+
+	pass := isEmpty(object)
+	if !pass {
+		Fail(t, fmt.Sprintf("Should be empty, but was %v", object), msgAndArgs...)
+	}
+
+	return pass
+
+}
+
+// NotEmpty asserts that the specified object is NOT empty.  I.e. not nil, "", false, 0 or either
+// a slice or a channel with len == 0.
+//
+//  if assert.NotEmpty(t, obj) {
+//    assert.Equal(t, "two", obj[1])
+//  }
+//
+// Returns whether the assertion was successful (true) or not (false).
+func NotEmpty(t TestingT, object interface{}, msgAndArgs ...interface{}) bool {
+
+	pass := !isEmpty(object)
+	if !pass {
+		Fail(t, fmt.Sprintf("Should NOT be empty, but was %v", object), msgAndArgs...)
+	}
+
+	return pass
+
+}
+
+// getLen try to get length of object.
+// return (false, 0) if impossible.
+func getLen(x interface{}) (ok bool, length int) {
+	v := reflect.ValueOf(x)
+	defer func() {
+		if e := recover(); e != nil {
+			ok = false
+		}
+	}()
+	return true, v.Len()
+}
+
+// Len asserts that the specified object has specific length.
+// Len also fails if the object has a type that len() not accept.
+//
+//    assert.Len(t, mySlice, 3, "The size of slice is not 3")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func Len(t TestingT, object interface{}, length int, msgAndArgs ...interface{}) bool {
+	ok, l := getLen(object)
+	if !ok {
+		return Fail(t, fmt.Sprintf("\"%s\" could not be applied builtin len()", object), msgAndArgs...)
+	}
+
+	if l != length {
+		return Fail(t, fmt.Sprintf("\"%s\" should have %d item(s), but has %d", object, length, l), msgAndArgs...)
+	}
+	return true
+}
+
+// True asserts that the specified value is true.
+//
+//    assert.True(t, myBool, "myBool should be true")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func True(t TestingT, value bool, msgAndArgs ...interface{}) bool {
+
+	if value != true {
+		return Fail(t, "Should be true", msgAndArgs...)
+	}
+
+	return true
+
+}
+
+// False asserts that the specified value is false.
+//
+//    assert.False(t, myBool, "myBool should be false")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func False(t TestingT, value bool, msgAndArgs ...interface{}) bool {
+
+	if value != false {
+		return Fail(t, "Should be false", msgAndArgs...)
+	}
+
+	return true
+
+}
+
+// NotEqual asserts that the specified values are NOT equal.
+//
+//    assert.NotEqual(t, obj1, obj2, "two objects shouldn't be equal")
+//
+// Returns whether the assertion was successful (true) or not (false).
+//
+// Pointer variable equality is determined based on the equality of the
+// referenced values (as opposed to the memory addresses).
+func NotEqual(t TestingT, expected, actual interface{}, msgAndArgs ...interface{}) bool {
+
+	if ObjectsAreEqual(expected, actual) {
+		return Fail(t, fmt.Sprintf("Should not be: %#v\n", actual), msgAndArgs...)
+	}
+
+	return true
+
+}
+
+// containsElement try loop over the list check if the list includes the element.
+// return (false, false) if impossible.
+// return (true, false) if element was not found.
+// return (true, true) if element was found.
+func includeElement(list interface{}, element interface{}) (ok, found bool) {
+
+	listValue := reflect.ValueOf(list)
+	elementValue := reflect.ValueOf(element)
+	defer func() {
+		if e := recover(); e != nil {
+			ok = false
+			found = false
+		}
+	}()
+
+	if reflect.TypeOf(list).Kind() == reflect.String {
+		return true, strings.Contains(listValue.String(), elementValue.String())
+	}
+
+	if reflect.TypeOf(list).Kind() == reflect.Map {
+		mapKeys := listValue.MapKeys()
+		for i := 0; i < len(mapKeys); i++ {
+			if ObjectsAreEqual(mapKeys[i].Interface(), element) {
+				return true, true
+			}
+		}
+		return true, false
+	}
+
+	for i := 0; i < listValue.Len(); i++ {
+		if ObjectsAreEqual(listValue.Index(i).Interface(), element) {
+			return true, true
+		}
+	}
+	return true, false
+
+}
+
+// Contains asserts that the specified string, list(array, slice...) or map contains the
+// specified substring or element.
+//
+//    assert.Contains(t, "Hello World", "World", "But 'Hello World' does contain 'World'")
+//    assert.Contains(t, ["Hello", "World"], "World", "But ["Hello", "World"] does contain 'World'")
+//    assert.Contains(t, {"Hello": "World"}, "Hello", "But {'Hello': 'World'} does contain 'Hello'")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func Contains(t TestingT, s, contains interface{}, msgAndArgs ...interface{}) bool {
+
+	ok, found := includeElement(s, contains)
+	if !ok {
+		return Fail(t, fmt.Sprintf("\"%s\" could not be applied builtin len()", s), msgAndArgs...)
+	}
+	if !found {
+		return Fail(t, fmt.Sprintf("\"%s\" does not contain \"%s\"", s, contains), msgAndArgs...)
+	}
+
+	return true
+
+}
+
+// NotContains asserts that the specified string, list(array, slice...) or map does NOT contain the
+// specified substring or element.
+//
+//    assert.NotContains(t, "Hello World", "Earth", "But 'Hello World' does NOT contain 'Earth'")
+//    assert.NotContains(t, ["Hello", "World"], "Earth", "But ['Hello', 'World'] does NOT contain 'Earth'")
+//    assert.NotContains(t, {"Hello": "World"}, "Earth", "But {'Hello': 'World'} does NOT contain 'Earth'")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func NotContains(t TestingT, s, contains interface{}, msgAndArgs ...interface{}) bool {
+
+	ok, found := includeElement(s, contains)
+	if !ok {
+		return Fail(t, fmt.Sprintf("\"%s\" could not be applied builtin len()", s), msgAndArgs...)
+	}
+	if found {
+		return Fail(t, fmt.Sprintf("\"%s\" should not contain \"%s\"", s, contains), msgAndArgs...)
+	}
+
+	return true
+
+}
+
+// Condition uses a Comparison to assert a complex condition.
+func Condition(t TestingT, comp Comparison, msgAndArgs ...interface{}) bool {
+	result := comp()
+	if !result {
+		Fail(t, "Condition failed!", msgAndArgs...)
+	}
+	return result
+}
+
+// PanicTestFunc defines a func that should be passed to the assert.Panics and assert.NotPanics
+// methods, and represents a simple func that takes no arguments, and returns nothing.
+type PanicTestFunc func()
+
+// didPanic returns true if the function passed to it panics. Otherwise, it returns false.
+func didPanic(f PanicTestFunc) (bool, interface{}) {
+
+	didPanic := false
+	var message interface{}
+	func() {
+
+		defer func() {
+			if message = recover(); message != nil {
+				didPanic = true
+			}
+		}()
+
+		// call the target function
+		f()
+
+	}()
+
+	return didPanic, message
+
+}
+
+// Panics asserts that the code inside the specified PanicTestFunc panics.
+//
+//   assert.Panics(t, func(){
+//     GoCrazy()
+//   }, "Calling GoCrazy() should panic")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func Panics(t TestingT, f PanicTestFunc, msgAndArgs ...interface{}) bool {
+
+	if funcDidPanic, panicValue := didPanic(f); !funcDidPanic {
+		return Fail(t, fmt.Sprintf("func %#v should panic\n\r\tPanic value:\t%v", f, panicValue), msgAndArgs...)
+	}
+
+	return true
+}
+
+// NotPanics asserts that the code inside the specified PanicTestFunc does NOT panic.
+//
+//   assert.NotPanics(t, func(){
+//     RemainCalm()
+//   }, "Calling RemainCalm() should NOT panic")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func NotPanics(t TestingT, f PanicTestFunc, msgAndArgs ...interface{}) bool {
+
+	if funcDidPanic, panicValue := didPanic(f); funcDidPanic {
+		return Fail(t, fmt.Sprintf("func %#v should not panic\n\r\tPanic value:\t%v", f, panicValue), msgAndArgs...)
+	}
+
+	return true
+}
+
+// WithinDuration asserts that the two times are within duration delta of each other.
+//
+//   assert.WithinDuration(t, time.Now(), time.Now(), 10*time.Second, "The difference should not be more than 10s")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func WithinDuration(t TestingT, expected, actual time.Time, delta time.Duration, msgAndArgs ...interface{}) bool {
+
+	dt := expected.Sub(actual)
+	if dt < -delta || dt > delta {
+		return Fail(t, fmt.Sprintf("Max difference between %v and %v allowed is %v, but difference was %v", expected, actual, delta, dt), msgAndArgs...)
+	}
+
+	return true
+}
+
+func toFloat(x interface{}) (float64, bool) {
+	var xf float64
+	xok := true
+
+	switch xn := x.(type) {
+	case uint8:
+		xf = float64(xn)
+	case uint16:
+		xf = float64(xn)
+	case uint32:
+		xf = float64(xn)
+	case uint64:
+		xf = float64(xn)
+	case int:
+		xf = float64(xn)
+	case int8:
+		xf = float64(xn)
+	case int16:
+		xf = float64(xn)
+	case int32:
+		xf = float64(xn)
+	case int64:
+		xf = float64(xn)
+	case float32:
+		xf = float64(xn)
+	case float64:
+		xf = float64(xn)
+	default:
+		xok = false
+	}
+
+	return xf, xok
+}
+
+// InDelta asserts that the two numerals are within delta of each other.
+//
+// 	 assert.InDelta(t, math.Pi, (22 / 7.0), 0.01)
+//
+// Returns whether the assertion was successful (true) or not (false).
+func InDelta(t TestingT, expected, actual interface{}, delta float64, msgAndArgs ...interface{}) bool {
+
+	af, aok := toFloat(expected)
+	bf, bok := toFloat(actual)
+
+	if !aok || !bok {
+		return Fail(t, fmt.Sprintf("Parameters must be numerical"), msgAndArgs...)
+	}
+
+	if math.IsNaN(af) {
+		return Fail(t, fmt.Sprintf("Actual must not be NaN"), msgAndArgs...)
+	}
+
+	if math.IsNaN(bf) {
+		return Fail(t, fmt.Sprintf("Expected %v with delta %v, but was NaN", expected, delta), msgAndArgs...)
+	}
+
+	dt := af - bf
+	if dt < -delta || dt > delta {
+		return Fail(t, fmt.Sprintf("Max difference between %v and %v allowed is %v, but difference was %v", expected, actual, delta, dt), msgAndArgs...)
+	}
+
+	return true
+}
+
+// InDeltaSlice is the same as InDelta, except it compares two slices.
+func InDeltaSlice(t TestingT, expected, actual interface{}, delta float64, msgAndArgs ...interface{}) bool {
+	if expected == nil || actual == nil ||
+		reflect.TypeOf(actual).Kind() != reflect.Slice ||
+		reflect.TypeOf(expected).Kind() != reflect.Slice {
+		return Fail(t, fmt.Sprintf("Parameters must be slice"), msgAndArgs...)
+	}
+
+	actualSlice := reflect.ValueOf(actual)
+	expectedSlice := reflect.ValueOf(expected)
+
+	for i := 0; i < actualSlice.Len(); i++ {
+		result := InDelta(t, actualSlice.Index(i).Interface(), expectedSlice.Index(i).Interface(), delta)
+		if !result {
+			return result
+		}
+	}
+
+	return true
+}
+
+func calcRelativeError(expected, actual interface{}) (float64, error) {
+	af, aok := toFloat(expected)
+	if !aok {
+		return 0, fmt.Errorf("expected value %q cannot be converted to float", expected)
+	}
+	if af == 0 {
+		return 0, fmt.Errorf("expected value must have a value other than zero to calculate the relative error")
+	}
+	bf, bok := toFloat(actual)
+	if !bok {
+		return 0, fmt.Errorf("expected value %q cannot be converted to float", actual)
+	}
+
+	return math.Abs(af-bf) / math.Abs(af), nil
+}
+
+// InEpsilon asserts that expected and actual have a relative error less than epsilon
+//
+// Returns whether the assertion was successful (true) or not (false).
+func InEpsilon(t TestingT, expected, actual interface{}, epsilon float64, msgAndArgs ...interface{}) bool {
+	actualEpsilon, err := calcRelativeError(expected, actual)
+	if err != nil {
+		return Fail(t, err.Error(), msgAndArgs...)
+	}
+	if actualEpsilon > epsilon {
+		return Fail(t, fmt.Sprintf("Relative error is too high: %#v (expected)\n"+
+			"        < %#v (actual)", actualEpsilon, epsilon), msgAndArgs...)
+	}
+
+	return true
+}
+
+// InEpsilonSlice is the same as InEpsilon, except it compares each value from two slices.
+func InEpsilonSlice(t TestingT, expected, actual interface{}, epsilon float64, msgAndArgs ...interface{}) bool {
+	if expected == nil || actual == nil ||
+		reflect.TypeOf(actual).Kind() != reflect.Slice ||
+		reflect.TypeOf(expected).Kind() != reflect.Slice {
+		return Fail(t, fmt.Sprintf("Parameters must be slice"), msgAndArgs...)
+	}
+
+	actualSlice := reflect.ValueOf(actual)
+	expectedSlice := reflect.ValueOf(expected)
+
+	for i := 0; i < actualSlice.Len(); i++ {
+		result := InEpsilon(t, actualSlice.Index(i).Interface(), expectedSlice.Index(i).Interface(), epsilon)
+		if !result {
+			return result
+		}
+	}
+
+	return true
+}
+
+/*
+	Errors
+*/
+
+// NoError asserts that a function returned no error (i.e. `nil`).
+//
+//   actualObj, err := SomeFunction()
+//   if assert.NoError(t, err) {
+//	   assert.Equal(t, actualObj, expectedObj)
+//   }
+//
+// Returns whether the assertion was successful (true) or not (false).
+func NoError(t TestingT, err error, msgAndArgs ...interface{}) bool {
+	if err != nil {
+		return Fail(t, fmt.Sprintf("Received unexpected error:\n%+v", err), msgAndArgs...)
+	}
+
+	return true
+}
+
+// Error asserts that a function returned an error (i.e. not `nil`).
+//
+//   actualObj, err := SomeFunction()
+//   if assert.Error(t, err, "An error was expected") {
+//	   assert.Equal(t, err, expectedError)
+//   }
+//
+// Returns whether the assertion was successful (true) or not (false).
+func Error(t TestingT, err error, msgAndArgs ...interface{}) bool {
+
+	if err == nil {
+		return Fail(t, "An error is expected but got nil.", msgAndArgs...)
+	}
+
+	return true
+}
+
+// EqualError asserts that a function returned an error (i.e. not `nil`)
+// and that it is equal to the provided error.
+//
+//   actualObj, err := SomeFunction()
+//   assert.EqualError(t, err,  expectedErrorString, "An error was expected")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func EqualError(t TestingT, theError error, errString string, msgAndArgs ...interface{}) bool {
+	if !Error(t, theError, msgAndArgs...) {
+		return false
+	}
+	expected := errString
+	actual := theError.Error()
+	// don't need to use deep equals here, we know they are both strings
+	if expected != actual {
+		return Fail(t, fmt.Sprintf("Error message not equal:\n"+
+			"expected: %q\n"+
+			"received: %q", expected, actual), msgAndArgs...)
+	}
+	return true
+}
+
+// matchRegexp return true if a specified regexp matches a string.
+func matchRegexp(rx interface{}, str interface{}) bool {
+
+	var r *regexp.Regexp
+	if rr, ok := rx.(*regexp.Regexp); ok {
+		r = rr
+	} else {
+		r = regexp.MustCompile(fmt.Sprint(rx))
+	}
+
+	return (r.FindStringIndex(fmt.Sprint(str)) != nil)
+
+}
+
+// Regexp asserts that a specified regexp matches a string.
+//
+//  assert.Regexp(t, regexp.MustCompile("start"), "it's starting")
+//  assert.Regexp(t, "start...$", "it's not starting")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func Regexp(t TestingT, rx interface{}, str interface{}, msgAndArgs ...interface{}) bool {
+
+	match := matchRegexp(rx, str)
+
+	if !match {
+		Fail(t, fmt.Sprintf("Expect \"%v\" to match \"%v\"", str, rx), msgAndArgs...)
+	}
+
+	return match
+}
+
+// NotRegexp asserts that a specified regexp does not match a string.
+//
+//  assert.NotRegexp(t, regexp.MustCompile("starts"), "it's starting")
+//  assert.NotRegexp(t, "^start", "it's not starting")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func NotRegexp(t TestingT, rx interface{}, str interface{}, msgAndArgs ...interface{}) bool {
+	match := matchRegexp(rx, str)
+
+	if match {
+		Fail(t, fmt.Sprintf("Expect \"%v\" to NOT match \"%v\"", str, rx), msgAndArgs...)
+	}
+
+	return !match
+
+}
+
+// Zero asserts that i is the zero value for its type and returns the truth.
+func Zero(t TestingT, i interface{}, msgAndArgs ...interface{}) bool {
+	if i != nil && !reflect.DeepEqual(i, reflect.Zero(reflect.TypeOf(i)).Interface()) {
+		return Fail(t, fmt.Sprintf("Should be zero, but was %v", i), msgAndArgs...)
+	}
+	return true
+}
+
+// NotZero asserts that i is not the zero value for its type and returns the truth.
+func NotZero(t TestingT, i interface{}, msgAndArgs ...interface{}) bool {
+	if i == nil || reflect.DeepEqual(i, reflect.Zero(reflect.TypeOf(i)).Interface()) {
+		return Fail(t, fmt.Sprintf("Should not be zero, but was %v", i), msgAndArgs...)
+	}
+	return true
+}
+
+// JSONEq asserts that two JSON strings are equivalent.
+//
+//  assert.JSONEq(t, `{"hello": "world", "foo": "bar"}`, `{"foo": "bar", "hello": "world"}`)
+//
+// Returns whether the assertion was successful (true) or not (false).
+func JSONEq(t TestingT, expected string, actual string, msgAndArgs ...interface{}) bool {
+	var expectedJSONAsInterface, actualJSONAsInterface interface{}
+
+	if err := json.Unmarshal([]byte(expected), &expectedJSONAsInterface); err != nil {
+		return Fail(t, fmt.Sprintf("Expected value ('%s') is not valid json.\nJSON parsing error: '%s'", expected, err.Error()), msgAndArgs...)
+	}
+
+	if err := json.Unmarshal([]byte(actual), &actualJSONAsInterface); err != nil {
+		return Fail(t, fmt.Sprintf("Input ('%s') needs to be valid json.\nJSON parsing error: '%s'", actual, err.Error()), msgAndArgs...)
+	}
+
+	return Equal(t, expectedJSONAsInterface, actualJSONAsInterface, msgAndArgs...)
+}
+
+func typeAndKind(v interface{}) (reflect.Type, reflect.Kind) {
+	t := reflect.TypeOf(v)
+	k := t.Kind()
+
+	if k == reflect.Ptr {
+		t = t.Elem()
+		k = t.Kind()
+	}
+	return t, k
+}
+
+// diff returns a diff of both values as long as both are of the same type and
+// are a struct, map, slice or array. Otherwise it returns an empty string.
+func diff(expected interface{}, actual interface{}) string {
+	if expected == nil || actual == nil {
+		return ""
+	}
+
+	et, ek := typeAndKind(expected)
+	at, _ := typeAndKind(actual)
+
+	if et != at {
+		return ""
+	}
+
+	if ek != reflect.Struct && ek != reflect.Map && ek != reflect.Slice && ek != reflect.Array {
+		return ""
+	}
+
+	e := spewConfig.Sdump(expected)
+	a := spewConfig.Sdump(actual)
+
+	diff, _ := difflib.GetUnifiedDiffString(difflib.UnifiedDiff{
+		A:        difflib.SplitLines(e),
+		B:        difflib.SplitLines(a),
+		FromFile: "Expected",
+		FromDate: "",
+		ToFile:   "Actual",
+		ToDate:   "",
+		Context:  1,
+	})
+
+	return "\n\nDiff:\n" + diff
+}
+
+var spewConfig = spew.ConfigState{
+	Indent:                  " ",
+	DisablePointerAddresses: true,
+	DisableCapacities:       true,
+	SortKeys:                true,
+}

vendor/github.com/stretchr/testify/assert/doc.go

@@ -0,0 +1,45 @@
+// Package assert provides a set of comprehensive testing tools for use with the normal Go testing system.
+//
+// Example Usage
+//
+// The following is a complete example using assert in a standard test function:
+//    import (
+//      "testing"
+//      "github.com/stretchr/testify/assert"
+//    )
+//
+//    func TestSomething(t *testing.T) {
+//
+//      var a string = "Hello"
+//      var b string = "Hello"
+//
+//      assert.Equal(t, a, b, "The two words should be the same.")
+//
+//    }
+//
+// if you assert many times, use the format below:
+//
+//    import (
+//      "testing"
+//      "github.com/stretchr/testify/assert"
+//    )
+//
+//    func TestSomething(t *testing.T) {
+//      assert := assert.New(t)
+//
+//      var a string = "Hello"
+//      var b string = "Hello"
+//
+//      assert.Equal(a, b, "The two words should be the same.")
+//    }
+//
+// Assertions
+//
+// Assertions allow you to easily write test code, and are global funcs in the `assert` package.
+// All assertion functions take, as the first argument, the `*testing.T` object provided by the
+// testing framework. This allows the assertion funcs to write the failings and other details to
+// the correct place.
+//
+// Every assertion function also takes an optional string message as the final argument,
+// allowing custom error messages to be appended to the message the assertion method outputs.
+package assert

vendor/github.com/stretchr/testify/assert/errors.go

@@ -0,0 +1,10 @@
+package assert
+
+import (
+	"errors"
+)
+
+// AnError is an error instance useful for testing.  If the code does not care
+// about error specifics, and only needs to return the error for example, this
+// error should be used to make the test code more readable.
+var AnError = errors.New("assert.AnError general error for testing")

vendor/github.com/stretchr/testify/assert/forward_assertions.go

@@ -0,0 +1,16 @@
+package assert
+
+// Assertions provides assertion methods around the
+// TestingT interface.
+type Assertions struct {
+	t TestingT
+}
+
+// New makes a new Assertions object for the specified TestingT.
+func New(t TestingT) *Assertions {
+	return &Assertions{
+		t: t,
+	}
+}
+
+//go:generate go run ../_codegen/main.go -output-package=assert -template=assertion_forward.go.tmpl

vendor/github.com/stretchr/testify/assert/http_assertions.go

@@ -0,0 +1,106 @@
+package assert
+
+import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strings"
+)
+
+// httpCode is a helper that returns HTTP code of the response. It returns -1
+// if building a new request fails.
+func httpCode(handler http.HandlerFunc, method, url string, values url.Values) int {
+	w := httptest.NewRecorder()
+	req, err := http.NewRequest(method, url+"?"+values.Encode(), nil)
+	if err != nil {
+		return -1
+	}
+	handler(w, req)
+	return w.Code
+}
+
+// HTTPSuccess asserts that a specified handler returns a success status code.
+//
+//  assert.HTTPSuccess(t, myHandler, "POST", "http://www.google.com", nil)
+//
+// Returns whether the assertion was successful (true) or not (false).
+func HTTPSuccess(t TestingT, handler http.HandlerFunc, method, url string, values url.Values) bool {
+	code := httpCode(handler, method, url, values)
+	if code == -1 {
+		return false
+	}
+	return code >= http.StatusOK && code <= http.StatusPartialContent
+}
+
+// HTTPRedirect asserts that a specified handler returns a redirect status code.
+//
+//  assert.HTTPRedirect(t, myHandler, "GET", "/a/b/c", url.Values{"a": []string{"b", "c"}}
+//
+// Returns whether the assertion was successful (true) or not (false).
+func HTTPRedirect(t TestingT, handler http.HandlerFunc, method, url string, values url.Values) bool {
+	code := httpCode(handler, method, url, values)
+	if code == -1 {
+		return false
+	}
+	return code >= http.StatusMultipleChoices && code <= http.StatusTemporaryRedirect
+}
+
+// HTTPError asserts that a specified handler returns an error status code.
+//
+//  assert.HTTPError(t, myHandler, "POST", "/a/b/c", url.Values{"a": []string{"b", "c"}}
+//
+// Returns whether the assertion was successful (true) or not (false).
+func HTTPError(t TestingT, handler http.HandlerFunc, method, url string, values url.Values) bool {
+	code := httpCode(handler, method, url, values)
+	if code == -1 {
+		return false
+	}
+	return code >= http.StatusBadRequest
+}
+
+// HTTPBody is a helper that returns HTTP body of the response. It returns
+// empty string if building a new request fails.
+func HTTPBody(handler http.HandlerFunc, method, url string, values url.Values) string {
+	w := httptest.NewRecorder()
+	req, err := http.NewRequest(method, url+"?"+values.Encode(), nil)
+	if err != nil {
+		return ""
+	}
+	handler(w, req)
+	return w.Body.String()
+}
+
+// HTTPBodyContains asserts that a specified handler returns a
+// body that contains a string.
+//
+//  assert.HTTPBodyContains(t, myHandler, "www.google.com", nil, "I'm Feeling Lucky")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func HTTPBodyContains(t TestingT, handler http.HandlerFunc, method, url string, values url.Values, str interface{}) bool {
+	body := HTTPBody(handler, method, url, values)
+
+	contains := strings.Contains(body, fmt.Sprint(str))
+	if !contains {
+		Fail(t, fmt.Sprintf("Expected response body for \"%s\" to contain \"%s\" but found \"%s\"", url+"?"+values.Encode(), str, body))
+	}
+
+	return contains
+}
+
+// HTTPBodyNotContains asserts that a specified handler returns a
+// body that does not contain a string.
+//
+//  assert.HTTPBodyNotContains(t, myHandler, "www.google.com", nil, "I'm Feeling Lucky")
+//
+// Returns whether the assertion was successful (true) or not (false).
+func HTTPBodyNotContains(t TestingT, handler http.HandlerFunc, method, url string, values url.Values, str interface{}) bool {
+	body := HTTPBody(handler, method, url, values)
+
+	contains := strings.Contains(body, fmt.Sprint(str))
+	if contains {
+		Fail(t, fmt.Sprintf("Expected response body for \"%s\" to NOT contain \"%s\" but found \"%s\"", url+"?"+values.Encode(), str, body))
+	}
+
+	return !contains
+}