30 lines
1.2 KiB
Plaintext
30 lines
1.2 KiB
Plaintext
==== tests/cases/compiler/genericConstraint2.ts (3 errors) ====
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interface Comparable<T> {
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comparer(other: T): number;
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}
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function compare<T extends Comparable<T>>(x: T, y: T): number {
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~~~~~~~~~~~~~~~~~~~~~~~
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!!! Constraint of a type parameter cannot reference any type parameter from the same type parameter list.
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if (x == null) return y == null ? 0 : -1;
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if (y == null) return 1;
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return x.comparer(y);
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}
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class ComparableString implements Comparable<string>{
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~~~~~~~~~~~~~~~~
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!!! Class 'ComparableString' incorrectly implements interface 'Comparable<string>':
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!!! Property 'comparer' is missing in type 'ComparableString'.
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constructor(public currentValue: string) { }
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localeCompare(other) {
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return 0;
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}
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}
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var a = new ComparableString("a");
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var b = new ComparableString("b");
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var c = compare<ComparableString>(a, b);
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~~~~~~~~~~~~~~~~
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!!! Type 'ComparableString' does not satisfy the constraint 'Comparable<unknown>':
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!!! Property 'comparer' is missing in type 'ComparableString'. |