Provide Mcoks

[jonny-improbable]

Thanks for this awesome project 👍

As part ofmaintaining a suite of Google App Scripts, we have created a number of mock objects which are loaded into the node environment and allow our tests, and subjects under test, to make use of the Goolge App Script globals - I wondered if gas-local would be a good repository to house them for others to use?

These mocks are simple and provide a mixture of fakes and test-doubles, for example:

global.Utilities = {};

Utilities.formatDate = jest.fn(function () {
  return "";
});

Utilities.base64Encode = jest.fn(function (str) {
  return btoa(str);
});

One potential problem I can forsee is being strongly opinionated on using Jest for creating mocks; whilst we could remove all calls to jest.fn(); this would put a lot of onus on the test-author to mock out globals in their test, ie:

describe("my suite", () => {
  it("should do something...", () => {
    // Setup jest mocks
   Utilities.formatDate = jest.fn();
  });
});

Do let me know if I've missed something; I feel like I'm reinventing the wheel to large extent with implementing all those mocks!