Awesome
loader.js ![Build Status](https://travis-ci.org/ember-cli/loader.js.svg?branch=master)
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.