Chain behaviours for the same command/payload

It isn’t unusual in Jest to chain behaviours of a mock, for instance with several sequential calls to mockImplementationOnce. This useful when you want to reproduce some specific behaviour, such as a call succeeding the first time but failing the second time.

I ran into this problem when I was refactoring my code to use this library. I was able to overcome it by refactoring my code a bit and giving each call/responses unique Ids.

I would consider this lower priority since in most cases you should be able to work around it. Still it might help to simplify test code.

[dmattia]

Sure, I do this like:

    const dbMock = mockClient(someClient);

    // The first call should return LastEvaluatedKey, signaling that pagination should happen
    dbMock.send.onFirstCall().resolves({
      Items: [{ pk: { S: 'a' }}],
      LastEvaluatedKey: { pk: { S: 'a'} },
    });

    // The second call is the final call
    dbMock.send.onSecondCall().resolves({
      Items: [{ pk: { S: 'b' }} ] ,
    });

[m-radzikowski]

It took a moment but is now released in v0.6.2 🎉

See the new resolvesOnce(), rejectsOnce(), and callsFakeOnce() mock functions.