min-require

Minimal implementation of CommonJS require API

Introduction

This tiny library provides a way to organize your client-side scripts in CommonJs style. It only implements minimum features that required to work and nothing more. It also detects circular dependency and throws error. The behaviour is different from NodeJs while NodeJs tries to return uninitialized exports object when resolving circular dependency.

Example:

define('foo', function(require, module, exports) {

  exports.hello = 'Hello';
  exports.world = 'World';

});

define('my-module', function(require, module, exports) {

  var foo = require('foo');
  module.exports = foo.hello + ' ' + foo.world;

});

console.log(require('my-module'));   // 'Hello World'

Example 2:

define('A', function(require, module, exports) {
  require('B');
});

define('B', function(require, module, exports) {
  require('A');
});

require('A');   // Error: circular: A, B

Using in browser

• Include min-require.js in <script> tag
• Define your modules
• Require at least one module in main script
• A module must be required (directly or indirectly) from main script in order to run

define('fibonacci', function(require, module, exports) {

  module.exports = function f(n) {
    if (typeof n !== 'number' || n < 0) throw new Error('Invalid argument')
    if (n === 0) return 1;
    if (n === 1) return 2;
    return f(n-1) + f(n-2);
  };

});

define('app', function(require, module, exports) {

  var fibonacci = require('fibonacci');
  console.log(fibonacci(10));   // 144

});

require('app');

Using AMD syntax

define('module1', ['exports'], function(exports) {
  exports.value = 10;
});

define('module2', ['module1'], function(module1) {
  return module1.value * 2;
})

console.log(require('module2')); // 20

Testing

define('AlphaModule', function (require, module) {
  function getName() {
    return 'AlphaModule';
  }

  module.exports = {
    getName: getName
  };
});

define('BravoModule', function (require, module) {
  var alpha = require('AlphaModule');
  function getName() {
      return 'BravoModule' + 'On' + alpha.getName();
  }

  module.exports = {
    getName: getName
  };
});

describe('BravoModule', function () {
  it('should be easily tested', function () {
    var SUT = require('BravoModule', {
      AlphaModule: {getName: function () {return 'StubAlphaModule'}}
    });
    expect(SUT.getName()).toEqual('BravoModuleOnStubAlphaModule');
  });
});

Using with Gulp

This library was originally created for working with gulp-wrap-require. You can find the more completed example here: mithril-boilerplate.

Sample gulpfile.js:

var wrapRequire = require('gulp-wrap-require');
var concat = require('gulp-concat');

gulp.task('buildAppScripts', function(cb) {
  gulp.src('src/app/**/*.js'), {base: 'src/app'})
    .pipe(wrapRequire())
    .pipe(concat('main.js'))
    .pipe(gulp.dest('build/assets')
    .on('end', cb || function(){})
    .on('error', console.log);
});

Sample directory tree:

/
  build/
    assets/
  src/
    app/
      alpha/
        a.js
      beta/
        b.js
      foo.js
      bar.js

Result:

Running gulp buildAppScripts on above directory tree will yield build/assets/main.js:

define('alpha/a', function() {
  // src/app/alpha/a.js
});

define('beta/b', function() {
  // src/app/beta/b.js
});

define('foo', function() {
  // src/app/foo.js
});

define('bar', function() {
  // src/app/bar.js
});

API

define#CJS

define(id, callback)

Define a module using Simplified CommonJS Wrapper syntax.

• id must be string and unique
• callback: function(require, module, exports)

define#AMD

define(id, dependencies, callback)

Define a module using Asynchronous Module Definition syntax.

• id must be string and unique
• dependencies must be an array of module names as strings
• callback: function(module1, module2, ...) that returns the module interface

The special module exports is supported as a dependency to expose the module's interface.

require

require(id, stub)

Require a module. If stub object is specified it will stub out all dependencies using the stub object.

• Return: exports object
• id must be defined
• stub: (optional) {dependency1: {method1: function () {}, method2: function () {}}}

reset

reset()

Forgets about every previously defined module. Useful for testing.

License

MIT.