Jest service mocks have wrong types

[DaSchTour]

Discussed in #613

^{Originally posted by DaSchTour June 1, 2023}
I have some code that uses mocks and jest functions like mockReturnValue. For example like this

const fooService = spectator.inject(FooService);
fooService.someMethod.mockReturnValue({foo: 'bar'});

This worked fine but now suddenly I get typescript errors TS2339: Property 'mockReturnValue' does not exist on type '((key: string | null, location?: string | undefined) => Observable ) & CompatibleSpy'..

It looks like typescript doesn't use the jest typings but the jasmine version.

I'm not sure if that is an issue with my configuration, with a wrong version of jest or maybe caused by TypeScript 5. Did anybody else expect similar issues?

This issue is also present in https://github.com/ngneat/spectator/blob/master/projects/spectator/jest/test/auth.service.spec.ts

So probably there is something wrong with the jest SpyObject typings.

Interesting is, that when opening the file in VSCode or IntelliJ there are errors shown, but the test run correctly without issues.

[elmarbeckmann]

Same issue when I upgraded to Spectator version 15. (icw NG16)

[chimurai]

@DaSchTour @elmarbeckmann Could you verify the fix in PR #615?

[DaSchTour]

@chimurai when looking on the specs in spectator repo it looks fine. When trying to verify it with npm link I get a lot of new very strange errors. But the typings for mocks are correct.

[chimurai]

@DaSchTour Could you try to manually patch node_modules/@ngneat/spectator/jest/lib/mock.d.ts? (instead of using npm link)

And apply the change from https://github.com/ngneat/spectator/pull/615/files

[DaSchTour]

@chimurai sorry for the late response. I now checked with patching the file and all test work fine. Thanks a lot