Problems with restoring a getter

[fatfisz]

Hi I'm currently using SinonJS (v. 1.17.3 on Node.js 4.x) and I'm experiencing a small problem while restoring a mocked getter. There's this little code in the restore method:

if (object[property] === method) {
    object[property] = wrappedMethod;
}

This can sometimes cause problems if object[property] is a getter. I suggest the check is only performed if Object.defineProperty wasn't called before, as at this point we are sure that the property has been restored and the check is unnecessary.

Because the authors of SinonJS aren't very fond of mocking getters/setters, let me provide you with a bit of a background.

Here's a class that contains the getter I'm mocking:

const privateDataMap = new WeakMap();

export default class DataStore {
  constructor(input) {
    privateDataMap.set(this, {
      errors: {},
      ...
    });
  }

  ...

  get errors() {
    return privateDataMap.get(this).errors;
  }
}

I'm using this class inside some function that I'm testing and I wanted to check if the errors are passed correctly. Because I can't manipulate the object itself, I turned to the prototype, and so I've written:

const stub = sinon.stub(DataStore.prototype, 'errors', {
  get() {
    return 'test errors';
  },
});

Later on I want to clean up, and so I call stub.restore(). This obviously causes an error, because at the point object[property] is called the getter has been restored, and so the call really looks like this: privateDataMap.get(DataStore.prototype).errors;.
Because I can't access privateDataMap from the outside (that's the point), I can't set the value for privateDataMap.get(DataStore.prototype), and so a type error occurs.

[fatfisz]

Sorry, didn't notice that this is a duplicate of #897. For when is the release of 2.0.0 planned? :)

[fatso83]

Last year - feel free to push it forwards :-) No seriously, it's getting there a lot faster nowadays with the help we have been getting on #966 from (amongst others) @fearphage and @jonnyreeves , but there is still quite a bit left.

You can get the next pre-release by doing npm install sinon@next

[fatfisz]

I've already installed the pre-release and it's working without trouble. Good work! :)