loader.js

4.7.0 • Public • Published

loader.js Build Status

Minimal AMD loader mostly stolen from @wycats.

No Conflict

To prevent the loader from overriding require, define, or requirejs you can instruct the loader to use no conflict mode by providing it an alternative name for the various globals that are normally used.

Example:

loader.noConflict({
  define: 'newDefine',
  require: 'newRequire'
});

Extra stuff

define.alias('old/path', 'new-name')

define.alias allows creation of a symlink from one module to another, for example:

define('foo', [], () => 'hi');
define.alias('foo', 'foo/bar/baz');
 
require('foo/bar/baz') // => 'hi';
require('foo') === require('foo/bar/baz');

require('require')

When within a module, one can require require. This provides a require scoped to the current module. Enabling dynamic, relatively path requires.

 
define('foo/apple', ['require'], function() { return 'apple'; });
define('foo/bar', ['require'], function(require){ return require('./apple'););
 
require('foo/bar'); // 'apple';

This scoped require also enables a module some reflection, in this case the ability for a module to see its own moduleId;

 
define('my/name/is', ['require'], function(require) {
  require.moduleId // => 'my/name/is';
});

define.exports('foo', {})

define.exports enables a fastpath for non-lazy dependency-less modules, for example:

Rather then:

define("my-foo-app/templates/application", ["exports"], function (exports) {
  "use strict";
 
  Object.defineProperty(exports, "__esModule", {
    value: true
  });
 
  exports.default = Ember.HTMLBars.template({ "id": "VVZNWoRm", "block": "{\"statements\":[[1,[26,[\"welcome-page\"]],false],[0,\"\\n\"],[0,\"\\n\"],[1,[26,[\"outlet\"]],false]],\"locals\":[],\"named\":[],\"yields\":[],\"hasPartials\":false}", "meta": { "moduleName": "my-foo-app/templates/application.hbs" } });
});

We can author:

define.exports('my-app/template/apple', { hbs: true, "id": "VVZNWoRm", "block": "{\"statements\":[[1,[26,[\"welcome-page\"]],false],[0,\"\\n\"],[0,\"\\n\"],[1,[26,[\"outlet\"]],false]],\"locals\":[],\"named\":[],\"yields\":[],\"hasPartials\":false}", "meta": { "moduleName": "my-foo-app/templates/application.hbs" }});

benefits:

  • less bytes
  • no reification step
  • no need to juggle pre-parse voodoo.

require.unsee('foo');

require.unsee allows one to unload a given module. note The side-effects of that module cannot be unloaded. This is quite useful, especially for test suites. Being able to unload run tests, mitigates many common memory leaks:

example:

define('my-app/tests/foo-test.js', ['qunit'], function(qunit) {
  let app;
 
  qunit.module('my module', {
    beforeEach() {
      app = new App();
    }
 
    // forgot to `null` out app in the afterEach
  });
 
  test('my app exists', function(assert) {
    assert.ok(app);
  })
})

Note: To be able to take advantage of alternate define method name, you will also need to ensure that your build tooling generates using the alternate. An example of this is done in the emberjs-build project in the babel-enifed-module-formatter plugin.

wrapModules

It is possible to hook loader to augment or transform the loaded code. wrapModules is an optional method on the loader that is called as each module is originally loaded. wrapModules must be a function of the form wrapModules(name, callback). The callback is the original AMD callback. The return value of wrapModules is then used in subsequent requests for name

This functionality is useful for instrumenting code, for instance in code coverage libraries.

loader.wrapModules = function(name, callback) {
            if (shouldTransform(name) {
                    return myTransformer(name, callback);
                }
            }
            return callback;
    };

makeDefaultExport

loader.js creates default exports for ember-cli amdStrict mode. If you do not need this behavior you can disable it like so:

loader.makeDefaultExport = false;

Tests

We use testem for running our test suite.

You may run them with:

npm test

You can also launch testem development mode with:

npm run test:dev

License

loader.js is MIT Licensed.

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npm i loader.js

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Version

4.7.0

License

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Collaborators

  • ember-cli
  • kratiahuja
  • krisselden
  • mmun
  • rwjblue
  • stefanpenner