Correct type of pino's stream parameter

[quisido]

The second parameter of the pino function can be set to undefined. This is relevant when dependency injecting a stream:

function create(stream: DestinationStream | undefined): Logger {
  return pino({ level: 'debug' }, stream); // <-- second parameter is incorrectly marked as invalid
}

This allows me to use create(undefined) for default behavior (stdio), but also create({ write: jest.fn() }) for mocked behavior in unit tests, without creating a new branch.

With the definition prior to this PR, the following code is required:

function create(stream: DestinationStream | undefined): Logger {
  if (typeof stream === 'undefined') { // <-- this branch shouldn't be required, because it does nothing different
    return pino({ level: 'debug' });
  }
  return pino({ level: 'debug' }, stream);
}

This creates an unnecessary code branch, as it's the same runtime behavior.

[mcollina]

Can you add a test with tsd?

[quisido]

Sorry for the delay, @mcollina . I've added it. 👍

[mcollina]

lgtm

[quisido]

Is it possible to re-run the failed test? I think it timed out.