genericFunctionInference1.errors.txt

tests/cases/compiler/genericFunctionInference1.ts(135,14): error TS2345: Argument of type '<a>(value: { key: a; }) => a' is not assignable to parameter of type '(value: Data) => string'.
  Type 'number' is not assignable to type 'string'.


==== tests/cases/compiler/genericFunctionInference1.ts (1 errors) ====
    declare function pipe<A extends any[], B>(ab: (...args: A) => B): (...args: A) => B;
    declare function pipe<A extends any[], B, C>(ab: (...args: A) => B, bc: (b: B) => C): (...args: A) => C;
    declare function pipe<A extends any[], B, C, D>(ab: (...args: A) => B, bc: (b: B) => C, cd: (c: C) => D): (...args: A) => D;
    
    declare function list<T>(a: T): T[];
    declare function box<V>(x: V): { value: V };
    declare function foo<T extends { value: T }>(x: T): T;
    
    const f00 = pipe(list);
    const f01 = pipe(list, box);
    const f02 = pipe(box, list);
    const f03 = pipe(x => list(x), box);
    const f04 = pipe(list, x => box(x));
    const f05 = pipe(x => list(x), x => box(x))
    const f06 = pipe(list, pipe(box));
    const f07 = pipe(x => list(x), pipe(box));
    const f08 = pipe(x => list(x), pipe(x => box(x)));
    const f09 = pipe(list, x => x.length);
    const f10 = pipe(foo);
    const f11 = pipe(foo, foo);
    
    const g00: <T>(x: T) => T[] = pipe(list);
    const g01: <T>(x: T) => { value: T[] } = pipe(list, box);
    const g02: <T>(x: T) => { value: T }[] = pipe(box, list);
    const g03: <T>(x: T) => { value: T[] } = pipe(x => list(x), box);
    const g04: <T>(x: T) => { value: T[] } = pipe(list, x => box(x));
    const g05: <T>(x: T) => { value: T[] } = pipe(x => list(x), x => box(x))
    const g06: <T>(x: T) => { value: T[] } = pipe(list, pipe(box));
    const g07: <T>(x: T) => { value: T[] } = pipe(x => list(x), pipe(box));
    const g08: <T>(x: T) => { value: T[] } = pipe(x => list(x), pipe(x => box(x)));
    const g09: <T>(x: T) => number = pipe(list, x => x.length);
    const g10: <T extends { value: T }>(x: T) => T = pipe(foo);
    const g12: <T extends { value: T }>(x: T) => T = pipe(foo, foo);
    
    declare function pipe2<A, B, C, D>(ab: (a: A) => B, cd: (c: C) => D): (a: [A, C]) => [B, D];
    
    const f20 = pipe2(list, box);
    const f21 = pipe2(box, list);
    const f22 = pipe2(list, list);
    const f23 = pipe2(box, box);
    const f24 = pipe2(f20, f20);
    const f25 = pipe2(foo, foo);
    const f26 = pipe2(f25, f25);
    
    declare function pipe3<A, B, C>(ab: (a: A) => B, ac: (a: A) => C): (a: A) => [B, C];
    
    const f30 = pipe3(list, box);
    const f31 = pipe3(box, list);
    const f32 = pipe3(list, list);
    
    declare function pipe4<A, B, C>(funcs: [(a: A) => B, (b: B) => C]): (a: A) => C;
    
    const f40 = pipe4([list, box]);
    const f41 = pipe4([box, list]);
    
    declare function pipe5<A, B>(f: (a: A) => B): { f: (a: A) => B };
    
    const f50 = pipe5(list);  // No higher order inference
    
    declare function wrap3<A, B, C>(f: (a: A, b1: B, b2: B) => C): (a: A, b1: B, b2: B) => C;
    declare function baz<T, U extends T>(t1: T, t2: T, u: U): [T, U];
    
    let f60 = wrap3(baz);
    
    declare const list2: {
        <T>(a: T): T[];
        foo: string;
        bar(): number;
    }
    
    let f70 = pipe(list2, box);
    let f71 = pipe(box, list2);
    
    declare class Point {
        constructor(x: number, y: number);
        readonly x: number;
        readonly y: number;
    }
    
    declare class Bag<T> {
        constructor(...args: T[]);
        contains(value: T): boolean;
        static foo: string;
    }
    
    function asFunction<A extends any[], B>(cf: new (...args: A) => B) {
        return (...args: A) => new cf(...args);
    }
    
    const newPoint = asFunction(Point);
    const newBag = asFunction(Bag);
    const p1 = new Point(10, 20);
    const p2 = newPoint(10, 20);
    const bag1 = new Bag(1, 2, 3);
    const bag2 = newBag('a', 'b', 'c');
    
    declare class Comp<P> {
        props: P;
        constructor(props: P);
    }
    
    type CompClass<P> = new (props: P) => Comp<P>;
    
    declare function myHoc<P>(C: CompClass<P>): CompClass<P>;
    
    type GenericProps<T> = { foo: number, stuff: T };
    
    declare class GenericComp<T> extends Comp<GenericProps<T>> {}
    
    const GenericComp2 = myHoc(GenericComp);
    
    // #417
    
    function mirror<A, B>(f: (a: A) => B): (a: A) => B { return f; }
    var identityM = mirror(identity);
    
    var x = 1;
    var y = identity(x);
    var z = identityM(x);
    
    // #3038
    
    export function keyOf<a>(value: { key: a; }): a {
        return value.key;
    }
    export interface Data {
        key: number;
        value: Date;
    }
    
    var data: Data[] = [];
    
    declare function toKeys<a>(values: a[], toKey: (value: a) => string): string[];
    
    toKeys(data, keyOf);  // Error
                 ~~~~~
!!! error TS2345: Argument of type '<a>(value: { key: a; }) => a' is not assignable to parameter of type '(value: Data) => string'.
!!! error TS2345:   Type 'number' is not assignable to type 'string'.
    
    // #9366
    
    function flip<a, b, c>(f: (a: a, b: b) => c): (b: b, a: a) => c {
      return (b: b, a: a) => f(a, b);
    }
    function zip<T, U>(x: T, y: U): [T, U] {
      return [x, y];
    }
    
    var expected: <T, U>(y: U, x: T) => [T, U] = flip(zip);
    var actual = flip(zip);
    
    // #9366
    
    const map = <T, U>(transform: (t: T) => U) =>
        (arr: T[]) => arr.map(transform)
    
    const identityStr = (t: string) => t;
    
    const arr: string[] = map(identityStr)(['a']);
    const arr1: string[] = map(identity)(['a']);
    
    // #9949
    
    function of2<a, b>(one: a, two: b): [a, b] {
        return [one, two];
    }
    
    const flipped = flip(of2);
    
    // #29904.1
    
    type Component<P> = (props: P) => {};
    
    declare const myHoc1: <P>(C: Component<P>) => Component<P>;
    declare const myHoc2: <P>(C: Component<P>) => Component<P>;
    
    declare const MyComponent1: Component<{ foo: 1 }>;
    
    const enhance = pipe(
        myHoc1,
        myHoc2,
    );
    
    const MyComponent2 = enhance(MyComponent1);
    
    // #29904.2
    
    const fn20 = pipe((_a?: {}) => 1);
    
    // #29904.3
    
    type Fn = (n: number) => number;
    const fn30: Fn = pipe(
        x => x + 1,
        x => x * 2,
    );
    
    const promise = Promise.resolve(1);
    promise.then(
        pipe(
            x => x + 1,
            x => x * 2,
        ),
    );
    
    // #29904.4
    
    declare const getString: () => string;
    declare const orUndefined: (name: string) => string | undefined;
    declare const identity: <T>(value: T) => T;
    
    const fn40 = pipe(
        getString,
        string => orUndefined(string),
        identity,
    );
    
    // #29904.6
    
    declare const getArray: () => string[];
    declare const first: <T>(ts: T[]) => T;
    
    const fn60 = pipe(
        getArray,
        x => x,
        first,
    );
    
    const fn61 = pipe(
        getArray,
        identity,
        first,
    );
    
    const fn62 = pipe(
        getArray,
        x => x,
        x => first(x),
    );
    
    // Repro from #30297
    
    declare function foo2<T, U = T>(fn: T, a?: U, b?: U): [T, U];
    
    foo2(() => {});
    foo2(identity);
    foo2(identity, 1);
    
    // Repro from #30324
    
    declare function times<T>(fn: (i: number) => T): (n: number) => T[];
    const a2 = times(identity)(5); // => [0, 1, 2, 3, 4]