Add tests for `ZulipAsyncStorage.getItem` and `.setItem`. #4709

Although it doesn't give a reason why, the `Platform` doc [1] is clear that `isPad` is iOS-only; we can expect it to be missing on Android. We'd love to know whether an Android user is on a tablet, but it seems `Platform` doesn't yet give us a way to do that. Until it does, or until we use something else that does, make it really clear that we're not getting accurate info on Android. [1] https://reactnative.dev/docs/platform#ispad-ios

With a new mock for `TextCompressionModule`; we do that globally in case it's useful elsewhere. That module should have its own set of unit tests, if we plan to keep it; it looks like it doesn't yet.

…rage. Now, the type for the `callback` param matches what's in the libdef for `AsyncStorage`. I think the question mark in the `?(...) => Foo` syntax isn't what we'd normally choose, but `ZulipAsyncStorage` is a wrapper around `AsyncStorage` so it might as well match this detail. Also the callback in `getItem` wasn't being considered optional at all, and now it is, which it looks like our implementation expects.

…ccess. `null` gets passed on `.setItem`'s success, so we might as well be consistent and do the same thing with `.getItem`. I'm starting to think that `.getItem` and `.setItem`'s callback-based interfaces can be trimmed away, and callers can exclusively use the returned Promise.

A bug like this is another reason I'm continuing to think we should just not bother to maintain a callback-based interface, here and in `.setItem`, and just maintain the Promise-based interface. Before we vendored redux-persist, which is the home of these methods' only callers, this would have been trickier. But now it's easy to make those callers adapt to the Promise-based interface.

We don't and can't use `window.localStorage` [1], `window.sessionStorage` [2], or `localforage` [3]; those are (or they use) web APIs. So, trim all this stuff that's related to those out. I think I got it all, and no more; anyway, the app still runs, and storage seems to work fine. [1] https://developer.mozilla.org/en-US/docs/Web/API/Window/localStorage [2] https://developer.mozilla.org/en-US/docs/Web/API/Window/sessionStorage [3] https://github.com/localForage/localForage

It looks like the rest of this callback is only meant to run if there hasn't been an error. In practice, I think most of it wasn't running anyway, since there would have been an error like "TypeError: Cannot read property 'filter' of undefined" on the `allKeys.filter(...)` just below. Good to be explicit, though.

Instead, use these functions' returned Promises. This will let us drop ZulipAsyncStorage's callback-based interface, which will simplify its code. Done carefully to preserve the control flow.

This simplifies the code quite a bit.

We already treat them as read-only everywhere except for one case, touched in this commit, where we've had to suppress several different Flow errors [0]. So, mark them as read-only with `$ReadOnly` [1]. Treating `GlobalState`'s properties as read-only (except for that one exceptional case) is likely to be very stable: we treat them as read-only because the Redux state is a tree of objects that are all treated as immutable; see the Redux docs [2] and our architecture doc [3]. [0] See Greg's comments on this at zulip#4709 (comment) [1] https://flow.org/en/docs/types/utilities/#toc-readonly [2] http://redux.js.org [3] ./docs/architecture.md

…nce.

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Add tests for `ZulipAsyncStorage.getItem` and `.setItem`. #4709

Add tests for `ZulipAsyncStorage.getItem` and `.setItem`. #4709

Commits on Jun 3, 2021

Add tests for ZulipAsyncStorage.getItem and .setItem. #4709

Add tests for ZulipAsyncStorage.getItem and .setItem. #4709

Commits on Jun 3, 2021

Add tests for `ZulipAsyncStorage.getItem` and `.setItem`. #4709

Add tests for `ZulipAsyncStorage.getItem` and `.setItem`. #4709