14 lines
352 B
TypeScript
14 lines
352 B
TypeScript
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interface IPromise<T> {
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then<TResult>(successCallback: (promiseValue: T) => TResult, errorCallback?: (reason: any) => TResult): IPromise<TResult>;
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}
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var foo: IPromise<number>;
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foo.then((x) => {
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// x is inferred to be a number
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return "asdf";
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}).then((x) => {
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// x is inferred to be string
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x.length;
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return 123;
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});
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