Mocking a Module's Dependencies of webpack
最近的项目中使用了 webpack 及 karma 进行单元测试，遇到的问题是如何 mocking 需测试模块中的 dependencies.
Kentor 的文章给了答案：
One way to achieve this is to use rewire and its webpack version rewire-webpack. Rewire can be used to change private variables in a module.
安装
npm i rewire rewire-webpack --save-dev
配置
// karma.conf.js
var RewirePlugin = require('rewire-webpack');
module.exports = function(config) {
config.set({
...
webpack: {
// webpack configuration
plugins: [
new RewirePlugin()
]
}
});
};
测试
// module.js
var ActionModal = require('./ActionModal');
module.exports = {
alert: function(msg) {
ActionModal.alert(msg);
}
};
// spec.js
var rewire = require('rewire');
describe('module', function() {
var module = rewire('./module');
var ActionModal = jasmine.createSpyObj('ActionModal', ['alert']);
module.__set__('ActionModal', ActionModal);
it('alert', function() {
module.alert('msg');
expect(ActionModal.alert).toHaveBeenCalledWith('msg');
});
});
Enjoy it!