Question

Given the following Javascript, would it be better/more idiomatic to inject the MyService object into myMethod so that a fake version of MyService could be injected for testing? Or am I missing something?

var myObject = {
  myMethod: function() {
    var myService = new MyService();
    return myService.doSomething();
  }
}

Answer 1

Dependency injection always takes precedence over hard-coding the dependencies. Also, by coding to interfaces (assuming the myObject instance has been given a copy of a Service object that has a doSomething() method) could come handy here.