Can no longer stub window methods using sinon

[kevinkucharczyk]

Starting from Sinon version 11.1.0, it is no longer possible to stub properties and methods on window, as suggested in the readme:

let stub = sinon.stub(window, 'confirm');
stub.returns(true);

This will throw an error:

TypeError: Cannot read properties of undefined (reading 'get')
    at getAccessor (webpack://__ember_auto_import__/./node_modules/sinon/lib/sinon/util/core/wrap-method.js?:1:1061)
    at extendObjectWithWrappedMethods (webpack://__ember_auto_import__/./node_modules/sinon/lib/sinon/util/core/wrap-method.js?:8:208)
    at wrapMethod (webpack://__ember_auto_import__/./node_modules/sinon/lib/sinon/util/core/wrap-method.js?:8:87)
    at Function.stub (webpack://__ember_auto_import__/./node_modules/sinon/lib/sinon/stub.js?:3:1569)
    at Sandbox.stub (webpack://__ember_auto_import__/./node_modules/sinon/lib/sinon/sandbox.js?:8:720)
    at Object.<anonymous> (http://localhost:13123/assets/tests.js:41707:22)

I tracked it down to this PR in Sinon itself sinonjs/sinon#2378, which shipped in version 11.1.0. More specifically, it seems that Sinon may have a bug when trying to mock/stub properties on Proxy objects.

This may be related to issues like #99

I understand that this may be for Sinon to fix, but it would be worth updating the readme to account for this. Maybe include a built-in option to easily mock and restore window methods/properties?

[simonihmig]

Thanks for reporting!

I wonder what happens when you directly set the property, instead of letting stub do that, like (untested code, just off the top of my head):

let fake = sinon.fake();
fake.returns(true);
window.confirm = fake;