18 lines
645 B
JavaScript
18 lines
645 B
JavaScript
//// [optionalFunctionArgAssignability.ts]
|
|
interface Promise<T> {
|
|
then<U>(onFulfill?: (value: T) => U, onReject?: (reason: any) => U): Promise<U>;
|
|
}
|
|
|
|
var a = function then<U>(onFulfill?: (value: string) => U, onReject?: (reason: any) => U): Promise<U> { return null };
|
|
var b = function then<U>(onFulFill?: (value: number) => U, onReject?: (reason: any) => U): Promise<U> { return null };
|
|
a = b; // error because number is not assignable to string
|
|
|
|
|
|
//// [optionalFunctionArgAssignability.js]
|
|
var a = function then(onFulfill, onReject) {
|
|
return null;
|
|
};
|
|
var b = function then(onFulFill, onReject) {
|
|
return null;
|
|
};
|
|
a = b;
|