sorting fields for deterministic order

[contextshuffling]

When using reflection to get the fields from a class, the order of the fields is not guaranteed to be in any specific order. Some tests, like multiValueBindings_WithSingletonsAcrossMultipleInjectableTypes, may fail due to a different ordering returned by getDeclaredFields. This PR sorts the field array returned by getDeclaredFields to guarantee a deterministic order (in this PR, alphabetical order).

Please let me know if you want to discuss the changes more.

[JakeWharton]

It's not clear how that test would fail as each type only contains a single field. This is an expensive operation that should have no practical effect on real code. We should correct the test failures, if any.

Also, Dagger 1 isn't being worked on and almost certainly won't see any future release.

[contextshuffling]

Hi @JakeWharton ,

Sorry for the late response. The test in question is actually multiValueBindings_WithSingletonAndDefaultValues(), instead of the one mentioned in the original post, sorry about that.

This test prepares a class that has two fields. When getDeclaredFields() is eventually called using this class, the fields are not guaranteed by the API to come in a specific order, so it is possible for the order to flip. As such, the test can actually fail since right now it assumes a specific order. If during injection, the field that gets injected first will contain (100, 200), and the one gets injected second will contain {100, 201}. But as mentioned, it is not guaranteed that objects1 always gets injected first and thus, the test may fail when objects2 gets injected first.

While sorting the fields is what we propose in this PR, we understand that the operation is expensive. However, we would still like to make the test more robust. Would a valid solution be to assert that both scenarios are possible, so check if the values are one way or the other?

[JakeWharton]

I would prefer that, yes.