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require.js require a module with index.js

So I'm trying to set up Typescript and Chutzpah for testing purposes. Typescript is set up to output in this format:
define(['require', 'exports', './someModule'], function(require, exports, someModule) {
//examplecode
});
Which works fine, the problem occurs when someModule is actually a directory with an index.js.
/app
app.js
/someModule
index.js
require.js is unable to resolve someModule in this way and the test fails.
Is there any way to tell require.js that this is a module?

RequireJS won't automatically check for the presence of index.js and load that as your module. You need to tell RequireJS that when you want to load someModule, it should load someModule/index. I'd set a map in my call to require.config:
require.config({
[ ... ]
map: {
'*': {
someModule: 'someModule/index',
}
},
});
You have to adjust the name you give there so that it is a path relative to your baseUrl. It's not clear from the information you give in your question what it should be.
(For the record, there's also a packages setting that you could probably tweak to do what you want but putting something packages says "this is a package", which is not what you appear to have here. So I would not use it for what you are trying to do.)

I didn't like the configuration in map either. The most simple way I accomplished this was writing a plugin for require.
Let's name the plugin mod, where it is to be used as mod!module/someModule, you can also call it index as in index!module/someModule, whatever suits you best.
define(function(require, exports, module) {
// loading module/someModule/index.js with `mod!`
var someModule = require('mod!module/someModule');
// whatever this is about ..
module.exports = { .. };
});
So lets assume you have paths set in require's configuration with some sort of project structure:
- app
- modules
- someModule/index.js // the index we want to load
- someModule/..
- someModule/..
- etc
- plugins
- mod.js // plugin to load a module with index.js
Requires config:
require.config({
paths: {
'module': 'app/modules',
// the plugin we're going to use so
// require knows what mod! stands for
'mod': 'app/plugins/mod.js'
}
});
To read all the aspects of how to write a plugin, read the docs at requirejs.org. The simplest version would be to just rewrite the name of the requested "module" you are attempting to access and pass it back to load.
app/plugins/mod.js
(function() {
define(function () {
function parse(name, req) {
return req.toUrl(name + '/index.js');
}
return {
normalize: function(name, normalize) {
return normalize(name);
},
load:function (name, req, load) {
req([parse(name, req)], function(o) {
load(o);
});
}
};
});
})();
This is not production code, it's just a simple way to demonstrate that requires config wasn't meant to solve problems like this.

Loading webpack module in a require.js based project returns null

I'm trying to load a library that compiles to Webpack in a require.js project. While the library exposes an object, it returns null when required from the require.js project :
define(function(require, exports, module) {
[...]
require("./ext/mylib.core.js"); // -> null
})
Is there any flags that I can use in Webpack to enable AMD compliance ? There are some references to AMD in the generated library but as it is it does not seem to do anything.

The solution was in Webpack documentation : there is an outputLibrary flag that can be set to "amd" or "umd" and in that case webpack produces amd compliant modules.

EDIT 3:/EDIT: 4
Webpack is not cooperating it may seem, so another possibility would be to expose the module with the shim config option:
require.config({
paths: {
// Tell require where to find the webpack thingy
yourModule: 'path/to/the/webpack/asset'
},
shim: {
// This lets require ignore that there is no define
// call but will instead use the specified global
// as the module export
yourModule: {
exports: 'theGlobalThatIsPutInPlaceByWebpack'
}
}
});
This obviously only works in the case that the webpack stuff is putting something in the global scope. Hope this helps!
EDIT 2:
So I got the question wrong as pointed out in the comments. I didn't find any built-in functionality to produce AMD modules from webpack - the end result seems to be a static asset js file. You could wrap the result in a
define(function () {
return /* the object that webpack produces */;
});
block, maybe with the help of some after-build event (e.g. using this after build plugin for webpack). Then you should be able to require the module with an AMD loader.
Original Answer:
require.js loads it's dependencies asynchronously, you have to declare them explicitly when you're not using the r.js optimizer or the like. So if the module exposes an AMD definition it should work like this:
// It works the way you did it ...
define(['path/to/your/module'], function (require, exports, module) {
require('path/to/your/module'); // -> { ... }
});
// ... but I personally prefer this explicit syntax + it is
// friendlier to a code minifier
define(['path/to/your/module'], function (yourModule) {
console.log(yourModule); // { ... }
});
Maybe you have to configure your require instance, there are docs for that.
EDIT1: as pointed out the way the module is being accessed is not wrong but the dependencies were missing, so I added code that is closer to the original question.

How to properly require modules from mocha.opts file

I'm using the expect.js library with my mocha unit tests. Currently, I'm requiring the library on the first line of each file, like this:
var expect = require('expect.js');
describe('something', function () {
it('should pass', function () {
expect(true).to.be(true); // works
});
});
If possible, I'd like to remove the boilerplate require code from the first line of each file, and have my unit tests magically know about expect. I thought I might be able to do this using the mocha.opts file:
--require ./node_modules/expect.js/index.js
But now I get the following error when running my test:
ReferenceError: expect is not defined
This seems to make sense - how can it know that the reference to expect in my tests refers to what is exported by the expect.js library?
The expect library is definitely getting loaded, as if I change the path to something non-existent then mocha says:
"Error: Cannot find module './does-not-exist.js'"
Is there any way to accomplish what I want? I'm running my tests from a gulp task if perhaps that could help.

You are requiring the module properly but as you figured out, the symbols that the module export won't automatically find themselves into the global space. You can remedy this with your own helper module.
Create test/helper.js:
var expect = require("expect.js")
global.expect = expect;
and set your test/mocha.opts to:
--require test/helper

While Louis's answer is spot on, in the end I solved this with a different approach by using karma and the karma-chai plugin:
Install:
npm install karma-chai --save-dev
Configure:
karma.set({
frameworks: ['mocha', 'chai']
// ...
});
Use:
describe('something', function () {
it('should pass', function () {
expect(true).to.be(true); // works
});
});

Thanks to Louis answer and a bit of fiddling around I sorted out my test environment references using mocha.opts. Here is the complete setup.
My project is a legacy JavaScript application with a lot of "plain" js files which I wish to reference both in an html file using script tags and using require for unit testing with mocha.
I am not certain that this is good practice but I am used to Mocha for unit testing in node project and was eager to use the same tool with minimal adaptation.
I found that exporting is easy:
class Foo{...}
class Bar{...}
if (typeof module !== 'undefined') module.exports = { Foo, Bar };
or
class Buzz{...}
if (typeof module !== 'undefined') module.exports = Buzz;
However, trying to use require in all the files was an issue as the browser would complain about variables being already declared even when enclosed in an if block such as:
if (typeof require !== 'undefined') {
var {Foo,Bar} = require('./foobar.js');
}
So I got rid of the require part in the files and set up a mocha.opts file in my test folder with this content. The paths are relative to the root folder:
--require test/mocha.opts.js
mocha.opts.js content. The paths are relative to the location of the file:
global.assert = require('assert');
global.Foo = require("../foobar.js").Foo;
global.Bar = require("../foobar.js").Bar;
global.Buzz = require("../buzz.js");

RequireJS Optimization

I`m using r.js to optimize my app,
as i saw in several samples, i used build.json configuration file to config my optimization options.
The problem is that when i set reference to the output javascript file after optimization I`m getting the following error in the browser:
Uncaught ReferenceError: define is not defined main-built.js:14735
Looks like, all my app modules are exists but RequireJs is missing.
This is my build.json configuration file:
{
"baseUrl": "../",
"name": "src/modules/main",
"include": ["src/modules/main", "src/modules/navbar/navbar", "src/modules/contact/contact", "src/modules/about/about"],
"exclude": [], "optimize": "none", "out": "main-built.js",
"insertRequire": ["src/modules/main"]
}
How do i add requirejs to the output js file? maybe i need to add something else to config? or maybe the problem is not the config?
Thanks,
Ori

Try:
<script src="scripts/require.js" data-main="scripts/main-built"></script>

If I understood correctly, this is how it should work.
What r.js does is that it compiles all RequireJS modules into a single file. However you still need to load that file with RequireJS script, for example:
<script data-main="scripts/main" src="scripts/require.js"></script>
So just add a minified version of require.js to your website and load the optimized module using that.

You have to include require.js if you have modularized your project using RequireJS:
<script data-main="scripts/main" src="scripts/require.js"></script>
This is because RequireJS handles the loading of modules and resolving dependencies. Without it, your browser does not know what define means. A way to get around this is to use UMD (Universal Module Definition). This makes it so that your module can be used with or without RequireJS. You can see many examples here. One that fits your use case is:
// Uses AMD or browser globals to create a module.
// If you want something that will also work in Node, see returnExports.js
// If you want to support other stricter CommonJS environments,
// or if you need to create a circular dependency, see commonJsStrict.js
// Defines a module "amdWeb" that depends another module called "b".
// Note that the name of the module is implied by the file name. It is best
// if the file name and the exported global have matching names.
// If the 'b' module also uses this type of boilerplate, then
// in the browser, it will create a global .b that is used below.
// If you do not want to support the browser global path, then you
// can remove the `root` use and the passing `this` as the first arg to
// the top function.
(function (root, factory) {
if (typeof define === 'function' && define.amd) {
// AMD. Register as an anonymous module.
define(['b'], factory);
} else {
// Browser globals
root.amdWeb = factory(root.b);
}
}(this, function (b) {
//use b in some fashion.
// Just return a value to define the module export.
// This example returns an object, but the module
// can return a function as the exported value.
return {};
}));

NodeJS and Javascript (requirejs) dependency injection

I am currently using requirejs to manage module js/css dependencies.
I'd like to discover the possibilities of having node do this via a centralized config file.
So instead of manually doing something like
define([
'jquery'
'lib/somelib'
'views/someview']
within each module.
I'd have node inject the dependencies ie
require('moduleA').setDeps('jquery','lib/somelib','views/someview')
Anyway, I'm interested in any projects looking at dependency injection for node.
thanks

I've come up with a solution for dependency injection. It's called injectr, and it uses node's vm library and replaces the default functionality of require when including a file.
So in your tests, instead of require('libToTest'), use injectr('libToTest' { 'libToMock' : myMock });. I wanted to make the interface as straightforward as possible, with no need to alter the code being tested. I think it works quite well.
It's just worth noting that injectr files are relative to the working directory, unlike require which is relative to the current file, but that shouldn't matter because it's only used in tests.

I've previously toyed with the idea of providing an alternate require to make a form of dependency injection available in Node.js.
Module code
For example, suppose you have following statements in code.js:
fs = require('fs');
console.log(fs.readFileSync('text.txt', 'utf-8'));
If you run this code with node code.js, then it will print out the contents of text.txt.
Injector code
However, suppose you have a test module that wants to abstract away the file system.
Your test file test.js could then look like this:
var origRequire = global.require;
global.require = dependencyLookup;
require('./code.js');
function dependencyLookup (file) {
switch (file) {
case 'fs': return { readFileSync: function () { return "test contents"; } };
default: return origRequire(file);
}
}
If you now run node test.js, it will print out "test contents", even though it includes code.js.

I've also written a module to accomplish this, it's called rewire. Just use npm install rewire and then:
var rewire = require("rewire"),
myModule = rewire("./path/to/myModule.js"); // exactly like require()
// Your module will now export a special setter and getter for private variables.
myModule.__set__("myPrivateVar", 123);
myModule.__get__("myPrivateVar"); // = 123
// This allows you to mock almost everything within the module e.g. the fs-module.
// Just pass the variable name as first parameter and your mock as second.
myModule.__set__("fs", {
readFile: function (path, encoding, cb) {
cb(null, "Success!");
}
});
myModule.readSomethingFromFileSystem(function (err, data) {
console.log(data); // = Success!
});
I've been inspired by Nathan MacInnes's injectr but used a different approach. I don't use vm to eval the test-module, in fact I use node's own require. This way your module behaves exactly like using require() (except your modifications). Also debugging is fully supported.