Add --prefer-stable and --prefer-lowest to "require" command

Fixes #5314

doc/03-cli.md

@@ -195,6 +195,9 @@ php composer.phar require vendor/package:2.* vendor/package2:dev-master
   can take a bit of time to run so it is currently not done by default.
 * **--classmap-authoritative (-a):** Autoload classes from the classmap only.
   Implicitly enables `--optimize-autoloader`.
+* **--prefer-stable:** Prefer stable versions of dependencies.
+* **--prefer-lowest:** Prefer lowest versions of dependencies. Useful for testing minimal
+  versions of requirements, generally used with `--prefer-stable`.
 
 ## remove
 

src/Composer/Command/RequireCommand.php

@@ -47,6 +47,8 @@ class RequireCommand extends InitCommand
                 new InputOption('update-no-dev', null, InputOption::VALUE_NONE, 'Run the dependency update with the --no-dev option.'),
                 new InputOption('update-with-dependencies', null, InputOption::VALUE_NONE, 'Allows inherited dependencies to be updated with explicit dependencies.'),
                 new InputOption('ignore-platform-reqs', null, InputOption::VALUE_NONE, 'Ignore platform requirements (php & ext- packages).'),
+                new InputOption('prefer-stable', null, InputOption::VALUE_NONE, 'Prefer stable versions of dependencies.'),
+                new InputOption('prefer-lowest', null, InputOption::VALUE_NONE, 'Prefer lowest versions of dependencies.'),
                 new InputOption('sort-packages', null, InputOption::VALUE_NONE, 'Sorts packages when adding/updating a new dependency'),
                 new InputOption('optimize-autoloader', 'o', InputOption::VALUE_NONE, 'Optimize autoloader during autoloader dump'),
                 new InputOption('classmap-authoritative', 'a', InputOption::VALUE_NONE, 'Autoload classes from the classmap only. Implicitly enables `--optimize-autoloader`.'),
@@ -162,6 +164,8 @@ EOT
             ->setUpdateWhitelist(array_keys($requirements))
             ->setWhitelistDependencies($input->getOption('update-with-dependencies'))
             ->setIgnorePlatformRequirements($input->getOption('ignore-platform-reqs'))
+            ->setPreferStable($input->getOption('prefer-stable'))
+            ->setPreferLowest($input->getOption('prefer-lowest'))
         ;
 
         $exception = null;