Expand on our Timestamp mock

[AverageHelper]

Description

Our mocked Firebase.Timestamp class now covers Firestore's API for toDate, toMillis getters, and fromDate and fromMillis constructors.

The corresponding Jest mock functions may be used to inject return values to these functions, like so:

// ... import firebase, mockTimestampToMillis ...

mockTimestampToMillis.mockReturnValue(400);
console.log(new firebase.firestore.Timestamp().toMillis()); // prints '400'

Related issues

Depends on #38

How to test

jest

[FrozenKiwi]

I'm not sure if this change is inlcuded in this changelist (or if it listed somewhere else) but there is an issue in the timestamp implementation:

  static fromDate(date) {
    return (
      mockTimestampFromDate(...arguments) ||
      new Timestamp(date.getSeconds(), date.getMilliseconds() * 1000000)
    );
  }

note date.getSeconds returns only the number of seconds since the last minute, not the full number of seconds since epoch.

A suggested change here: thecointech@9bc4d4a

(or I can add this as a PR once the subCollections PR has been merged)

[AverageHelper]

That's a good point @FrozenKiwi. I believe date.getTime returns the time since reference in milliseconds, right? I'll put up a commit with that instead.

[sbatson5]

Nice work! 🙌 Just a couple of comments

[sbatson5]

🎉 Nice work 🙌

[AverageHelper]

Thanks! #40 is ready for review.