73 lines
1.2 KiB
TypeScript
73 lines
1.2 KiB
TypeScript
// @target: es2015
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// @strict: true
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// Test that callback parameters are related covariantly
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interface P<T> {
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then(cb: (value: T) => void): void;
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};
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interface A { a: string }
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interface B extends A { b: string }
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function f1(a: P<A>, b: P<B>) {
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a = b;
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b = a; // Error
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}
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function f2(a: Promise<A>, b: Promise<B>) {
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a = b;
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b = a; // Error
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}
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interface AList1 {
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forEach(cb: (item: A) => void): void;
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}
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interface BList1 {
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forEach(cb: (item: B) => void): void;
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}
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function f11(a: AList1, b: BList1) {
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a = b;
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b = a; // Error
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}
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interface AList2 {
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forEach(cb: (item: A) => boolean): void;
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}
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interface BList2 {
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forEach(cb: (item: A) => void): void;
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}
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function f12(a: AList2, b: BList2) {
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a = b;
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b = a; // Error
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}
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interface AList3 {
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forEach(cb: (item: A) => void): void;
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}
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interface BList3 {
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forEach(cb: (item: A, context: any) => void): void;
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}
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function f13(a: AList3, b: BList3) {
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a = b;
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b = a; // Error
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}
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interface AList4 {
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forEach(cb: (item: A) => A): void;
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}
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interface BList4 {
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forEach(cb: (item: B) => B): void;
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}
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function f14(a: AList4, b: BList4) {
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a = b;
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b = a; // Error
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}
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