Add a clean-up script for use as a pre-commit hook

Change-Id: I0e87cbd2d653f4125e2a3d40cda30a3464a7a287

CONTRIBUTING.md

@@ -20,3 +20,18 @@ $wgEnableJavaScriptTest = true;
 
 Then open `http://URL_OF_MEDIAWIKI/index.php/Special:JavaScriptTest/qunit`
 (for example, <http://localhost/w/index.php/Special:JavaScriptTest/qunit>).
+
+Node-based code linting tests can be run locally using npm – run:
+
+<pre lang="bash">
+npm install && npm test
+</pre>
+
+
+## Pre-commit hook
+
+A pre-commit git hook script exists which will help flag up any issues and avoid irritating code review steps for you and reviewers. Simply do:
+
+<pre lang="bash">
+ln -s bin/pre-commit.sh ../.git/hooks/pre-commit
+</pre>

bin/pre-commit.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+
+# If the VE core sub-module was touched
+if git diff --quiet --cached lib/ve; then
+
+    GITBRANCH=`git rev-parse --abbrev-ref HEAD`;
+
+    # … and it doesn't look like
+    if [[ $GITBRANCH != "sync-repos" ]]; then
+        echo "VE core sub-module was touched but commit isn't from 'sync-repos'.";
+        exit 1;
+    fi
+
+fi
+
+# Stash any uncommited changes
+git stash -q --keep-index
+
+npm install || git stash pop -q && exit 1
+npm test && git add -u .docs/* || git stash pop -q && exit 1
+
+# Re-apply any uncommited changes
+git stash pop -q