Add syntax checker for contributors.

.gitignore

@@ -4,3 +4,4 @@ tests/Proxies/*
 tests/Hydrators/*
 phpunit.xml
 vendor/
+/bin/

composer.json

@@ -24,11 +24,22 @@
         "doctrine/mongodb": ">=1.1.5,<2.0"
     },
     "require-dev": {
-        "symfony/yaml": "~2.3|~3.0"
+        "symfony/yaml": "~2.3|~3.0",
+        "squizlabs/php_codesniffer": "~2.0"
     },
     "suggest": {
         "symfony/yaml": "Enables the YAML metadata mapping driver"
     },
+    "scripts": {
+        "post-install-cmd": [
+            "bash contrib/setup.sh"
+        ],
+        "post-update-cmd": [
+        ]
+    },
+    "config": {
+        "bin-dir": "bin"
+    },
     "autoload": {
         "psr-0": { "Doctrine\\ODM\\MongoDB": "lib/" }
     },

contrib/pre-commit

@@ -0,0 +1,39 @@
+#!/bin/bash
+# Pre-commit Git hook.
+# Runs PHP CS Fixer on PHP files.
+#
+# If you absolutely must commit without testing,
+# use: git commit --no-verify
+
+# This will check only staged files to be commited.
+filenames=($(git diff --staged --name-only HEAD))
+
+# This will set text to red in terminal.
+text_red=`tput setaf 1`
+# This will set the text to green in terminal.
+text_green=`tput setaf 2`
+# This will reset the terminal text to normal.
+text_reset=`tput sgr0`
+
+numberFilesChanged="${#filenames[@]}"
+
+if [[ $numberFilesChanged > 0 ]];
+then
+    echo "$numberFilesChanged files were changed, running php-cs-fixer"
+    # PHP CS Fixer.
+    for i in "${filenames[@]}"
+    do
+        if [[ $i == *.php ]];
+        then
+            ./bin/phpcbf --standard=PSR2 -p -n $i --diff
+
+      	    if [ $? -ne 0 ];
+            then
+              # File had some issues. Now it is fine. Add this file to git again.
+              git add $i
+            fi
+        fi
+    done
+fi
+
+echo "${text_green}PHP CS Fixer finished execution successfully.${text_reset}"

contrib/setup.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+
+# Copy the pre-commit hook to the current repository hooks directory.
+cp contrib/pre-commit .git/hooks/pre-commit
+
+# Add execution permission for pre-commit file.
+chmod +x .git/hooks/pre-commit