diff --git a/compose-function/compose-function-tests.ts b/compose-function/compose-function-tests.ts new file mode 100644 index 0000000000..dd0a80feff --- /dev/null +++ b/compose-function/compose-function-tests.ts @@ -0,0 +1,21 @@ +/// + +const numberToNumber = (a: number): number => a + 2; +const numberToString = (a: number): string => "foo"; +const stringToNumber = (a: string): number => 5; + +import composeFunction = require("compose-function"); +const t1: number = composeFunction(numberToNumber, numberToNumber)(5); +const t2: string = composeFunction(numberToString, numberToNumber)(5); +const t3: string = composeFunction(numberToString, stringToNumber)("f"); +const t4: (a: string) => number = composeFunction( + (f: (a: string) => number) => ((p: string) => 5), + (f: (a: number) => string) => ((p: string) => 4) + )(numberToString); + + +const t5: number = composeFunction(stringToNumber, numberToString, numberToNumber)(5); +const t6: string = composeFunction(numberToString, stringToNumber, numberToString, numberToNumber)(5); + +const t7: string = composeFunction( + numberToString, numberToNumber, stringToNumber, numberToString, stringToNumber)("fo"); diff --git a/compose-function/compose-function.d.ts b/compose-function/compose-function.d.ts new file mode 100644 index 0000000000..d4f205fd32 --- /dev/null +++ b/compose-function/compose-function.d.ts @@ -0,0 +1,31 @@ +// Type definitions for compose-function +// Project: https://github.com/stoeffel/compose-function +// Definitions by: Denis Sokolov +// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped + +declare module "compose-function" { + // Hardcoded signatures for 2-4 parameters + function f( + f1: (b: B) => C, + f2: (a: A) => B + ): (a: A) => C + function f( + f1: (b: C) => D, + f2: (a: B) => C, + f3: (a: A) => B + ): (a: A) => D + function f( + f1: (b: D) => E, + f2: (a: C) => D, + f3: (a: B) => C, + f4: (a: A) => B + ): (a: A) => E + + // Minimal typing for more than 4 parameters + function f( + f1: (a: any) => Result, + ...functions: Function[] + ): (a: any) => Result + + export = f; +}