Implemented way to add packages into suggest through CLI

src/Composer/Command/ConfigCommand.php

@@ -601,6 +601,18 @@ EOT
             return 0;
         }
 
+        if (preg_match('/^suggest\.(.+)/', $settingKey, $matches)) {
+            if ($input->getOption('unset')) {
+                $this->configSource->removeProperty($settingKey);
+
+                return 0;
+            }
+
+            $this->configSource->addProperty($settingKey, $values[0]);
+
+            return 0;
+        }
+
         // handle platform
         if (preg_match('/^platform\.(.+)/', $settingKey, $matches)) {
             if ($input->getOption('unset')) {

src/Composer/Json/JsonManipulator.php

@@ -167,6 +167,10 @@ class JsonManipulator
 
     public function addProperty($name, $value)
     {
+        if (substr($name, 0, 8) === 'suggest.') {
+            return $this->addSubNode('suggest', substr($name, 8), $value);
+        }
+
         if (substr($name, 0, 6) === 'extra.') {
             return $this->addSubNode('extra', substr($name, 6), $value);
         }
@@ -180,6 +184,10 @@ class JsonManipulator
 
     public function removeProperty($name)
     {
+        if (substr($name, 0, 8) === 'suggest.') {
+            return $this->removeSubNode('suggest', substr($name, 8));
+        }
+
         if (substr($name, 0, 6) === 'extra.') {
             return $this->removeSubNode('extra', substr($name, 6));
         }

tests/Composer/Test/Json/JsonManipulatorTest.php

@@ -1814,6 +1814,46 @@ class JsonManipulatorTest extends TestCase
 ', $manipulator->getContents());
     }
 
+    public function testAddSuggestWithPackage()
+    {
+        $manipulator = new JsonManipulator('{
+    "repositories": [
+        {
+            "type": "package",
+            "package": {
+                "authors": [],
+                "extra": {
+                    "package-xml": "package.xml"
+                }
+            }
+        }
+    ],
+    "suggest": {
+        "package": "Description"
+    }
+}');
+
+        $this->assertTrue($manipulator->addProperty('suggest.new-package', 'new-description'));
+        $this->assertEquals('{
+    "repositories": [
+        {
+            "type": "package",
+            "package": {
+                "authors": [],
+                "extra": {
+                    "package-xml": "package.xml"
+                }
+            }
+        }
+    ],
+    "suggest": {
+        "package": "Description",
+        "new-package": "new-description"
+    }
+}
+', $manipulator->getContents());
+    }
+
     public function testAddRepositoryCanInitializeEmptyRepositories()
     {
         $manipulator = new JsonManipulator('{