require-global

RequireJS loader plugin that allows to require global variables thus making dependencies on globals explicit.

Install

You can use bower to install it easily:

bower install --save require-global

Example

require.config({
    paths : {
        // Create alias to plugin (not needed if plugin is on the baseUrl)
        global: 'bower_components/require-global/sources/global'
    }
});

require([
    'global!window.alert',
    'global!setTimeout'
], function (alert, setTimeout) {
    setTimeout(function () {
      alert('Alerting through local variable!');
    }, 100);
});

Also require-global can be used as mocking mechanism for unit testing:

require.config({
    paths : {
        // Create alias to plugin (not needed if plugin is on the baseUrl)
        global: 'bower_components/require-global/sources/global'
    },
    
    map: {
        '*': {
            'JSON': 'JSONMock'
        }
    }
});

var JSONMock = {
    stringify: function () {
        alert('Stringifying object!');
    }
};

require([
    'global!JSON'
], function (JSON) {
    JSON.stringify({
        hello: 'world'
    }); // It will call mocked implementation of JSON.
});

Check examples folder for more examples.

Design

For now plugin supports property access expressions in dot notation only.

require([
    'global!JSON', // OK
    'global!window.JSON', // OK
    'global!window["JSON"]' // Illegal
], function () {
});

Internaly plugin parses property access expression and resolves it by traversing object graph starting from global object. No eval is used. It also mimics behavior of native property resolution algorithm and throws ReferenceError and TypeError according to the spec, so change from using globals to require-global should be non-breaking in most of the cases. Some of the functions have different behavior when called directly or indirectly. For example indirect call to eval causes evaled expression to execute in a global scope (in both strict and sloppy modes). For this cases require-global prints out a message to a console.

Additionaly, plugin does not try to validate syntactic correctnes of an expression for two reasons. First, such process can become quite error prone due to excessive amount of rules the are needed to be checked against (explained in this article). Second, we are not defining variables here, we are referencing existing variables/properties so mistakes result in error or undefined values that are quite easy to identify.

Roadmap

• Add error handling
• Add linting