Gruntfile.js

// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
/* jshint node: true, browser: false */
/* eslint-env node */

/**
 * @copyright  2014 Andrew Nicols
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

/**
 * Grunt configuration
 */

module.exports = function(grunt) {
    var path = require('path'),
        tasks = {},
        cwd = process.env.PWD || process.cwd(),
        semver = require('semver');

    // Verify the node version is new enough.
    var expected = semver.validRange(grunt.file.readJSON('package.json').engines.node);
    var actual = semver.valid(process.version);
    if (!semver.satisfies(actual, expected)) {
        grunt.fail.fatal('Node version too old. Require ' + expected + ', version installed: ' + actual);
    }

    // Windows users can't run grunt in a subdirectory, so allow them to set
    // the root by passing --root=path/to/dir.
    if (grunt.option('root')) {
        var root = grunt.option('root');
        if (grunt.file.exists(__dirname, root)) {
            cwd = path.join(__dirname, root);
            grunt.log.ok('Setting root to ' + cwd);
        } else {
            grunt.fail.fatal('Setting root to ' + root + ' failed - path does not exist');
        }
    }

    var inAMD = path.basename(cwd) == 'amd';

    // Globbing pattern for matching all AMD JS source files.
    var amdSrc = [inAMD ? cwd + '/src/*.js' : '**/amd/src/*.js'];

    /**
     * Function to generate the destination for the uglify task
     * (e.g. build/file.min.js). This function will be passed to
     * the rename property of files array when building dynamically:
     * http://gruntjs.com/configuring-tasks#building-the-files-object-dynamically
     *
     * @param {String} destPath the current destination
     * @param {String} srcPath the  matched src path
     * @return {String} The rewritten destination path.
     */
    var uglifyRename = function(destPath, srcPath) {
        destPath = srcPath.replace('src', 'build');
        destPath = destPath.replace('.js', '.min.js');
        destPath = path.resolve(cwd, destPath);
        return destPath;
    };

    // Project configuration.
    grunt.initConfig({
        uglify: {
			dynamic_mappings: {
                files: grunt.file.expandMapping(
                    ['**/src/*.js', '!**/node_modules/**'],
                    '',
                    {
                        cwd: process.cwd(),
                        rename: function(destBase, destPath) {
                            destPath = destPath.replace('src', 'build');
                            destPath = destPath.replace('.js', '.min.js');
                            destPath = path.resolve(process.cwd(), destPath);
                            return destPath;
                        }
                    }
                )
            }
        }
    });

    tasks.startup = function() {
        // Are we in a YUI directory?
        if (path.basename(path.resolve(cwd, '../../')) == 'yui') {
            grunt.task.run('yui');
        // Are we in an AMD directory?
        } else if (inAMD) {
            grunt.task.run('amd');
        } else {
            // Run them all!.
            grunt.task.run('css');
            grunt.task.run('js');
        }
    };

    // On watch, we dynamically modify config to build only affected files. This
    // method is slightly complicated to deal with multiple changed files at once (copied
    // from the grunt-contrib-watch readme).
    var changedFiles = Object.create(null);
    var onChange = grunt.util._.debounce(function() {
          var files = Object.keys(changedFiles);
          grunt.config('uglify.amd.files', [{expand: true, src: files, rename: uglifyRename}]);
          changedFiles = Object.create(null);
    }, 200);

    grunt.event.on('watch', function(action, filepath) {
          changedFiles[filepath] = action;
          onChange();
    });

    // Register NPM tasks.
    grunt.loadNpmTasks('grunt-contrib-uglify');

    // Register JS tasks.
    grunt.registerTask('amd', ['uglify']);
    grunt.registerTask('js', ['amd', 'yui']);

    // Register the startup task.
    grunt.registerTask('startup', 'Run the correct tasks for the current directory', tasks.startup);

    // Register the default task.
    grunt.registerTask('default', ['startup']);
};