Enable strict function types #1082
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| @@ -60,7 +60,7 @@ export enum TimerId { | |||
| * | |||
| * Supports cancellation (via cancel()) and early execution (via skipDelay()). | |||
| */ | |||
| class DelayedOperation<T> implements CancelablePromise<T> { | |||
| class DelayedOperation<T extends AnyJs | void> implements CancelablePromise<T> { | |||
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All of this AnyJs | void repetition makes me wonder if there's a useful abstraction to extract... but I'm not quite sure. Does an OptionalAnyJs make sense (and would it be useful anywhere besides here)? Or perhaps an OperationReturnValue type alias in this file?
I don't feel strongly... we just repeat it half a dozen times here, so I'm wondering... It's probably fine as-is though.
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I'll see what I can do. An alias local to one file it shouldn't be a problem, I don't think. void appears to be a bit of a weird concept at the intersection of Typescript and Javascript. See microsoft/TypeScript#20006 (comment) (but maybe avoid reading entire comment chain if you value your time and sanity). The gist of it is the AnyJs definition is "any value" (you can assign undefined to something), whereas, I think, void is intended to mean "no value" (let x = void; does not work). Per linked comment, you can technically end up with a value of void , but you probably shouldn't.
I think modifying our top type, AnyJs, to their recommended top type, null | undefined | {} might work, but I haven't tried it yet because that seems like it could have far-reaching implications. FWIW, Typescript 3.0 introduces unknown that I think is what we would actually want in this case: https://blogs.msdn.microsoft.com/typescript/2018/07/30/announcing-typescript-3-0/#the-unknown-type
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Oooh, yes unknown will be nice to have. Good find.
To be clear, only "see what you can do" if you feel like it. This is okay as-is too.
This reverts commit 22ed571.
After making some errors that would've been caught via more strict type checking, I explored what would be required to enable stricter checking.
Let me know what you think.