Code-Checker is a tool distributed by Moodle HQ which lets you validate code against core coding standards. You install it as a local plugin in a development environment and run it against specified files. It then spits out all kinds of nit-picky errors:

theme/stellar/layout/default.php

  • #76: ····<?php·//·echo·$OUTPUT->page_heading();·?>
  • This comment is 67% valid code; is this commented out code?
  • Inline comments must start with a capital letter, digit or 3-dots sequence
  • Inline comments must end in full-stops, exclamation marks, or question marks

Code-Checker leverages the PHP_CodeSniffer tool; in essence it’s a set of CodeSniffer definitions wrapped in a Moodle plugin. This adds a fair amount of overhead for testing coding standards–you shouldn’t need a functional Moodle environment, nor for that matter a web server.

My preferred integration tool is gulp.js, a task-runner built on node. It’s similar to grunt but without all the front-loaded configuration. There’s a plugin for gulp called gulp-phpcs which integrates PHP_CodeSniffer with gulp and lets you check the files in your project. Happily it was pretty simple to do this with Moodle.

First, you need to have PHP_CodeSniffer available in your development environment. This is how I did it on my Macbook:

cd /usr/local
mkdir scripts
cd scripts
git clone https://github.com/squizlabs/PHP_CodeSniffer.git phpcs

I then added that directory to my PATH:

PATH=/usr/local/scripts/phpcs/scripts:$PATH

Finally, I cloned in the Moodle plugin and added its standards definition to the installed paths for PHP_CodeSniffer:

git clone https://github.com/moodlehq/moodle-local_codechecker.git moodlecs
cd phpcs
./scripts/phpcs --config-set installed_paths ../moodlecs

At this point we’re ready to integrate it into gulp. We need to install the gulp-phpcs module and add it to the project:

npm install gulp-phpcs --save-dev

Now we provide a basic configuration in our gulpfile.js. This example will check all the php files in Lafayette’s Stellar theme:

// List of modules used.
var gulp    = require('gulp'),
    phpcs   = require('gulp-phpcs');    // Moodle standards.

// Moodle coding standards.
gulp.task('standards', function() {
  return gulp.src(['*.php', './layout/**/*.php', './lang/**/*.php'])
    .pipe(phpcs({
      standard: 'moodle'
    })) 
    .pipe(phpcs.reporter('log'));
});

Invoked from the command line, we get the same results as from the web interface, but faster and without the overhead:

[10:24:21] PHP Code Sniffer found a problem in ../theme_stellar/layout/default.php
Message:
 Error: Command failed: 
 
 FILE: STDIN
 --------------------------------------------------------------------------------
 FOUND 0 ERROR(S) AND 3 WARNING(S) AFFECTING 1 LINE(S)
 --------------------------------------------------------------------------------
 76 | WARNING | Inline comments must start with a capital letter, digit or
 | | 3-dots sequence
 76 | WARNING | Inline comments must end in full-stops, exclamation marks, or
 | | question marks
 76 | WARNING | This comment is 67% valid code; is this commented out code?
 --------------------------------------------------------------------------------

This also lets you create watcher tasks to catch errors introduced while developing.