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=== tests/cases/conformance/expressions/contextualTyping/functionExpressionContextualTyping1.ts ===
// When a function expression with no type parameters and no parameter type annotations
// is contextually typed (section 4.19) by a type T and a contextual signature S can be extracted from T
enum E { red, blue }
>E : E
>red : E.red
>blue : E.blue
// A contextual signature S is extracted from a function type T as follows:
// If T is a function type with exactly one call signature, and if that call signature is non- generic, S is that signature.
var a0: (n: number, s: string) => number = (num, str) => {
>a0 : (n: number, s: string) => number
>n : number
>s : string
>(num, str) => { num.toExponential(); return 0;} : (num: number, str: string) => number
>num : number
>str : string
num.toExponential();
>num.toExponential() : string
>num.toExponential : (fractionDigits?: number) => string
>num : number
>toExponential : (fractionDigits?: number) => string
return 0;
>0 : 0
}
class Class<T> {
>Class : Class<T>
>T : T
foo() { }
>foo : () => void
}
var a1: (c: Class<Number>) => number = (a1) => {
>a1 : (c: Class<Number>) => number
>c : Class<Number>
>Class : Class<T>
>Number : Number
>(a1) => { a1.foo(); return 1;} : (a1: Class<Number>) => number
>a1 : Class<Number>
a1.foo();
>a1.foo() : void
>a1.foo : () => void
>a1 : Class<Number>
>foo : () => void
return 1;
>1 : 1
}
// A contextual signature S is extracted from a function type T as follows:
// If T is a union type, let U be the set of element types in T that have call signatures.
// If each type in U has exactly one call signature and that call signature is non- generic,
// and if all of the signatures are identical ignoring return types,
// then S is a signature with the same parameters and a union of the return types.
var b1: ((s: string, w: boolean) => void) | ((s: string, w: boolean) => string);
>b1 : ((s: string, w: boolean) => void) | ((s: string, w: boolean) => string)
>s : string
>w : boolean
>s : string
>w : boolean
b1 = (k, h) => { };
>b1 = (k, h) => { } : (k: string, h: boolean) => void
>b1 : ((s: string, w: boolean) => void) | ((s: string, w: boolean) => string)
>(k, h) => { } : (k: string, h: boolean) => void
>k : string
>h : boolean
var b2: typeof a0 | ((n: number, s: string) => string);
>b2 : ((n: number, s: string) => number) | ((n: number, s: string) => string)
>a0 : (n: number, s: string) => number
>n : number
>s : string
b2 = (foo, bar) => { return foo + 1; }
>b2 = (foo, bar) => { return foo + 1; } : (foo: number, bar: string) => number
>b2 : ((n: number, s: string) => number) | ((n: number, s: string) => string)
>(foo, bar) => { return foo + 1; } : (foo: number, bar: string) => number
>foo : number
>bar : string
>foo + 1 : number
>foo : number
>1 : 1
b2 = (foo, bar) => { return "hello"; }
>b2 = (foo, bar) => { return "hello"; } : (foo: number, bar: string) => string
>b2 : ((n: number, s: string) => number) | ((n: number, s: string) => string)
>(foo, bar) => { return "hello"; } : (foo: number, bar: string) => string
>foo : number
>bar : string
>"hello" : "hello"
var b3: (name: string, num: number, boo: boolean) => void;
>b3 : (name: string, num: number, boo: boolean) => void
>name : string
>num : number
>boo : boolean
b3 = (name, number) => { };
>b3 = (name, number) => { } : (name: string, number: number) => void
>b3 : (name: string, num: number, boo: boolean) => void
>(name, number) => { } : (name: string, number: number) => void
>name : string
>number : number
var b4: (n: E) => string = (number = 1) => { return "hello"; };
>b4 : (n: E) => string
>n : E
>E : E
>(number = 1) => { return "hello"; } : (number?: E) => string
>number : E
>1 : 1
>"hello" : "hello"
var b5: (n: {}) => string = (number = "string") => { return "hello"; };
>b5 : (n: {}) => string
>n : {}
>(number = "string") => { return "hello"; } : (number?: {}) => string
>number : {}
>"string" : "string"
>"hello" : "hello"
// A contextual signature S is extracted from a function type T as follows:
// Otherwise, no contextual signature can be extracted from T and S is undefined.
var b6: ((s: string, w: boolean) => void) | ((n: number) => number);
>b6 : ((s: string, w: boolean) => void) | ((n: number) => number)
>s : string
>w : boolean
>n : number
var b7: ((s: string, w: boolean) => void) | ((s: string, w: number) => string);
>b7 : ((s: string, w: boolean) => void) | ((s: string, w: number) => string)
>s : string
>w : boolean
>s : string
>w : number
b6 = (k) => { k.toLowerCase() };
>b6 = (k) => { k.toLowerCase() } : (k: any) => void
>b6 : ((s: string, w: boolean) => void) | ((n: number) => number)
>(k) => { k.toLowerCase() } : (k: any) => void
>k : any
>k.toLowerCase() : any
>k.toLowerCase : any
>k : any
>toLowerCase : any
b6 = (i) => {
>b6 = (i) => { i.toExponential(); return i;} : (i: any) => any
>b6 : ((s: string, w: boolean) => void) | ((n: number) => number)
>(i) => { i.toExponential(); return i;} : (i: any) => any
>i : any
i.toExponential();
>i.toExponential() : any
>i.toExponential : any
>i : any
>toExponential : any
return i;
>i : any
}; // Per spec, no contextual signature can be extracted in this case. (Otherwise clause)
b7 = (j, m) => { }; // Per spec, no contextual signature can be extracted in this case. (Otherwise clause)
>b7 = (j, m) => { } : (j: any, m: any) => void
>b7 : ((s: string, w: boolean) => void) | ((s: string, w: number) => string)
>(j, m) => { } : (j: any, m: any) => void
>j : any
>m : any
class C<T, U> {
>C : C<T, U>
>T : T
>U : U
constructor() {
var k: ((j: T, k: U) => (T|U)[]) | ((j: number,k :U) => number[]) = (j, k) => {
>k : ((j: T, k: U) => (T | U)[]) | ((j: number, k: U) => number[])
>j : T
>T : T
>k : U
>U : U
>T : T
>U : U
>j : number
>k : U
>U : U
>(j, k) => { return [j, k]; } : (j: any, k: any) => any[]
>j : any
>k : any
return [j, k];
>[j, k] : any[]
>j : any
>k : any
} // Per spec, no contextual signature can be extracted in this case.
}
}
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