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Uninitialized local check still permits provably erroneous use-before-assign in closureΒ #60181
Description
π Search Terms
uninitialized, local, use before assign, control flow
π Version & Regression Information
- This changed in commit or PR error on variables that are used but never initializedΒ #55887
β― Playground Link
π» Code
let foo: string;
const setFoo = (): void => {
if (foo.length < 1) {
foo = 'foo';
}
};
export {}π Actual behavior
No TS Error
π Expected behavior
Variable 'foo' is used before being assigned.(2454)
Additional information about the issue
(this error is correctly reported if we never assign at all, as below)
let foo: string;
const setFoo = (): void => {
if (foo.length < 1) {
}
};
export {}Related, #60064.
Otherwise this can be solved by not considering assignments which occur unconditionally after a read.
Activity
[-]Uninitialized local permits provably erroneous use-before-assign[/-][+]Uninitialized local still permits provably erroneous use-before-assign in closure[/+]kirkwaiblinger commentedon Oct 11, 2024
Ryan Cavanaugh (@RyanCavanaugh) Sorry to ping, but I see the label has changed to "Awaiting More Feedback" but there's no other discussion. Is there anything you need from me or is discussion waiting on something else?
RyanCavanaugh commentedon Oct 11, 2024
Neither? For feedback like this we would be wanting to hear from more than one person encountering a particular kind of situation.
kirkwaiblinger commentedon Oct 11, 2024
Ah, gotcha, ok. I misunderstood what the label meant. Thanks for clarifying!
[-]Uninitialized local still permits provably erroneous use-before-assign in closure[/-][+]Uninitialized local check still permits provably erroneous use-before-assign in closure[/+]horberlan commentedon Oct 22, 2024
kirkwaiblinger commentedon Oct 22, 2024
poisnada (@horberlan) That does have the error, just on the
private processedDataline, though, right? I see that error in the playground