Simulating module initialization side-effects

Currently as far as I can tell, there is no way to mock side-effects in the initialization code of proxied modules. Example:

requiredmodule.js

module.exports = { foo: function () {}}

// ... other initialization code ...
if(somethingWentWrong) {
  throw new Error ("Something went wrong");
}

testedmodule.js

module.exports = {function bar() {
  var included;
  try {
    included = require('./requiredmodule.js');
  }
  catch (error) {
    // handle the error here
    return false;
  }
  included.foo();
  return true;
}}

testedmodule-test.js

var proxyquire = require('proxyquire').noCallThru();

describe('Testedmodule.bar', function() {
  it('should handle an initialization error thrown by a required module correctly', function() {
    var stubbedmodule = {
      'foo': function() { /* spy here */ },
      // ==== how do I specify the initialization code to make it error? ===
    };
    var testedmodule = proxyquire('testedmodule.js', {
      'requiredmodule.js': stubbedmodule
    });

    (function (){return testedmodule.bar()}).should.not.throw();
    (function (){return testedmodule.bar()}).should.equal(false);
    // also assert stubbedmodule.foo() not called
  });
});

Initially I was considering making a pull request to allow a replacement module to be specified as a string, but I saw that the tests explicitly handle the case where a module is a string so in order to simulate initialization code, I propose a @initialization property in a similar vein to @noCallThru that would allow one to specify code that would be run as if at the point of the initial require.

Thoughts? If this is seen as valuable effort, I'm happy to start work on a PR for this.

thlorenz / proxyquire