[Fiber] Use T | null instead of ?T types
#8978
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Flow maybe types accept both null and undefined. When the final parameter of a function accepts a maybe type, passing nothing (undefined) successfully typechecks, which can lead to bugs if the omission is accidental. Being forced to pass null is harder to screw up. Explicit null checks are also faster.
| @@ -1175,7 +1169,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(config : HostConfig<T, P, | |||
| // If we're not already inside a batch, we need to flush any task work | |||
| // that was created by the user-provided function. | |||
| if (!isPerformingWork && !isBatchingUpdates) { | |||
| performWork(TaskPriority); | |||
| performWork(TaskPriority, null); | |||
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Nice that we caught that.
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I actually don't know why Flow didn't catch this before, because the type on performWork was already Deadline | null
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@acdlite I found flow would catch this if Deadline was declared in ReactFiberScheduler.More details facebook/flow#3368
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@spicyj Mainly the Fiber type but I fixed most of the other optional types I found, too, with exceptions for things like user-facing functions. Possible there are a few that I missed. |
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This broke some stuff. At least |
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Ah. Actually I think the validation we do is correct, but we have an internal component that doesn't validate the ref. Interesting. |
Flow maybe types accept both null and undefined. When the final parameter of a function accepts a maybe type, passing nothing (undefined) successfully typechecks, which can lead to bugs if the omission is accidental. Being forced to pass null is harder to screw up.
Explicit null checks are also faster.