node_modules/grunt-contrib-requirejs/tasks/requirejs.js

/*
 * grunt-contrib-requirejs
 * http://gruntjs.com/
 *
 * Copyright (c) 2016 Tyler Kellen, contributors
 * Licensed under the MIT license.
 */

module.exports = function(grunt) {
  'use strict';

  var requirejs = require('requirejs');
  var LOG_LEVEL_TRACE = 0, LOG_LEVEL_WARN = 2;

  // TODO: extend this to send build log to grunt.log.ok / grunt.log.error
  // by overriding the r.js logger (or submit issue to r.js to expand logging support)
  requirejs.define('node/print', [], function() {
    return function print(msg) {
      if (msg.substring(0, 5) === 'Error') {
        grunt.log.errorlns(msg);
        grunt.fail.warn('RequireJS failed.');
      } else {
        grunt.log.oklns(msg);
      }
    };
  });

  grunt.registerMultiTask('requirejs', 'Build a RequireJS project.', function() {

    var done = this.async();
    var options = this.options({
      logLevel: grunt.option('verbose') ? LOG_LEVEL_TRACE : LOG_LEVEL_WARN,
      error: false,
      done: function(done){
        done();
      }
    });
    // The following catches errors in the user-defined `done` function and outputs them.
    var tryCatchDone = function(fn, done, output) {
      try {
        fn(done, output);
      } catch(e) {
        grunt.fail.warn('There was an error while processing your done function: "' + e + '"');
      }
    };

    // The following catches errors in the user-defined `error` function and passes them.
    // if the error function options is not set, this value should be undefined
    var tryCatchError = function(fn, done, err) {
      try {
        fn(done, err);
      } catch(e) {
        grunt.fail.fatal('There was an error while processing your error function: "' + e + '"');
      }
    };

    requirejs.optimize(
            options,
            tryCatchDone.bind(null, options.done, done ),
            options.error ? tryCatchError.bind(null, options.error, done ):undefined
    );

  });
};