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ts 2.3 -> 2.4 type predicate regression #19676
Description
TypeScript Version: 2.4.1
testFindTypeGuard.ts:
let el: Element;
const nodes: Node[] = [];
const result = nodes.find((n): n is HTMLFontElement => n.nodeName === "FONT");
el = result;
my.d.ts:
interface Array<T> {
find<U extends T>(predicate: (value: T, index: number, obj: Array<T>) => value is U): U | undefined;
}
Expected behavior:
Compiles fine (true for ts 2.1, 2.3)
Actual behavior: error TS2322: Build:Type 'Node' is not assignable to type 'Element'.
(tested with ts 2.4.1 and 2.7.0-dev.20171101)
Activity
fictitious commentedon Nov 2, 2017
This appears to be the commit that changed inferred type for
findfromHTMLFontElementtoNodeMarenkovIgor commentedon Nov 2, 2017
fictitious, commit diff is too complex for me. Any suggestion, how fix the code?
ahejlsberg commentedon Nov 2, 2017
Looks like a duplicate of #17451. Andy (Andrewkraft) (@Andy-MS) can you verify?
typescript-bot commentedon Nov 17, 2017
Automatically closing this issue for housekeeping purposes. The issue labels indicate that it is unactionable at the moment or has already been addressed.