RequireJS dependency helper

require_helper.js

var madge = require('madge'),
    _ = require('underscore');

function loadTargets (graph, depends, targets) {
    var parents = [],
        modules = [];

    depends.forEach(function(dep) {
        parents = _.uniq(parents.concat(graph.depends(dep)));
    });

    if (parents.length) {
        modules = _.difference(parents, Object.keys(targets));
        parents = _.uniq(
            parents.concat(
                parents,
                loadTargets(graph, modules, targets)
            )
        );
    }

    return parents;
};

module.exports = {
    //
    // Find a list of RequireJS targets that have a dependency
    // on a given module.
    //
    // :param name string: Module name
    // :param targets Array: List of RequireJS targets.
    // :param options object
    //
    findTargetsWithDependency: function(name, targets, options) {
        // Fetch dependency graph
        var dependencyObject = madge(options.path, {
            requireConfig: options.requireConfig,
            format: options.format
        });


        var deps = loadTargets(dependencyObject, [name], targets);
        return _.uniq(deps.concat(name));
    }
};

How to hook this into a Grunfile.js

  var targets = undefined,
      path = require('path'),
      requireJSHelper = require('./grunt/require_helper.js');

  grunt.event.on('watch', function(action, filepath) {
    if (path.extname(filepath) === '.js') {
      if (!targets) {
        targets = grunt.config('requirejs');
      }

      var name = filepath.replace("static/js/", "").replace(".js", "");
      var deps = requireJSHelper.findTargetsWithDependency(name, targets, {
        requireConfig: 'static/js/main.js',
        path: 'static/js'
      });

      grunt.config('requirejs', {});
      if (deps.length) {
        deps.forEach(function(key) {
          grunt.config(['requirejs', key], targets[key]);
        });
      } else if (Object.keys(targets).indexOf(name) !== -1) {
        grunt.config(['requirejs', name], targets[name]);
      }
    }
  });

Here are the requirejs targets

grunt.initConfig({
    requirejs: (function() {
      var targets = {};

      grunt.file.expand({cwd: 'static/js'}, 'pages/*.js')
        .forEach(function(file) {
          var name = file.replace('.js', '')
          targets[name] = {
            options: {
              optimize: "none",
              baseUrl: "./static/js",
              mainConfigFile: "static/js/main.js",
              include: ['../components/almond/almond.js', file],
              out: assets + "/dist/js/" + file
            }
          }
        });

      return targets;
    }())
});