feat(mergeMocks): support Promise

[MLKiiwy]

In my opinion it's a bug fix : mergeMocks function signature accept any type, so Promise type should be covered.

• add Promise support on mergeMocks
• add test to cover it

Context

In our application, we use the mocks with Promise result.
That gives us the possibility to test the "pending" and "error" state of a query or a mutation more easily. (and also the optimistic UI part can also be covered during pending state)
Actually it's really working fine and it's way easier to use on Frontend side compare to other mock utilities (for example the "mock" request system of apollo is awful)

We discover that if we define a custom mock + use Promise the custom mock override the expected result.
It's because of this test:

  if (isObject(customMock)) {
    return mergeObjects(genericMockFunction(), customMock);
  }

Promise is an object, but you can merge it as an object ...

--

• Make sure all of the significant new logic is covered by tests
• Rebase your changes on master so that they can be merged easily
• Make sure all tests and linter rules pass

[MLKiiwy]

@ardatan Hi, I don't understand why one action is failing can someone look at it or retry the action?

[ardatan]

Thank you for PR :) It is not important.

[theguild-bot]

The latest changes of this PR are available as alpha in npm: 6.0.17-alpha-f4bafe01.0

Quickly update your package.json by running:

npx match-version @graphql-tools 6.0.17-alpha-f4bafe01.0