25 lines
638 B
TypeScript
25 lines
638 B
TypeScript
// @strict: true
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// repro from https://github.com/Microsoft/TypeScript/issues/25274
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export function safeInvoke<A1, R>(
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func: ((arg1: A1) => R) | null | undefined,
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arg1: A1
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): R | undefined {
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if (func) {
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return func(arg1);
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} else {
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return undefined;
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}
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}
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interface Props {
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onFoo?(value: string): boolean;
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onBar?(value: string): void;
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}
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function bad<P extends Props>(props: Readonly<P>) {
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safeInvoke(props.onFoo, "blah");
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// ERROR HERE!!!
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// Type R in signature of safeInvoke incorrectly inferred as {} instead of void!
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safeInvoke(props.onBar, "blah");
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}
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