jmcdo29/createmock-unexpected-return

Odd Jest Error

When using @golevelup/ts-jest with Nest's new autoMock feature, if no return or resolve value is provided for the mock, then jest provides a rather strange error message.

Unexpected return from a matcher function.
Matcher functions should return an object in the following format:
  {message?: string | function, pass: boolean}
'{"actual": {}, "expected": "some string", "message": [Function anonymous], "name": "toEqual", "pass": {}}' was returned

I've found that this is because there's no mock return value from the mock created by createMock. You can see the setup in the test.ts file, while I admit that the foo method should be told what to return via mockReturnValue, I just wanted to point out that this error does arise. It looks like this is similar to #160.

Steps to reproduce

1. clone
2. install
3. test

Expected Behavior

Jest reports that the return is undefined