Rewireify

Rewireify is a port of Rewire for Browserify that adds setter and getter methods to each module so that their behaviour can be modified for better unit testing. With Rewireify you can:

• Inject mocks for other modules
• Leak private variables
• Override variables within the module

Rewireify is compatible with Browserify 3+

Usage

First install and save Rewireify into your project's development dependencies:

$ npm install rewireify --save-dev

Include the Rewireify transform as part of your test bundle:

$ browserify -e app.js -o test-bundle.js -t rewireify -s test-bundle

Rewireify can also ignore certain files with the --ignore option and a filename or glob expression. Multiple files or patterns can be excluded by separating them with commas:

$ browserify -e app.js -o test-bundle.js -t [ rewireify --ignore filename.js,**/*-mixin.js ] -s test-bundle

Now you can inspect, modify and override your modules internals in your tests. The __get__ and __set__ methods are the same as Rewire:

var bundle = require("./path/to/test-bundle");
 
// Private variables can be leaked...
subject.__get__("secretKey");
 
// ...or modified
subject.__set__("secretKey", 1234);
 
// Nested properties can be inspected or modified
subject.__set__("user.firstname", "Joe");
 
// Dependencies can be mocked...
subject.__set__("config", {
  cache: false,
  https: false
});
 
// ...or methods stubbed
subject.__set__("http.get", function(url, cb) {
  cb("This method has been stubbed");
});
 
// And everything can be reverted
var revert = subject.__set__("port", 3000);
 
revert();

For more details check out the Rewire documentation.