関数のモック import * as Utils from "hogehoge" jest.mock("hogehoge") jest .spyOn(Utils, "hogeFunc") .mockReturnValue(exampleValue)

作ってみた。 const replace: <T, S extends T>( list: T[], condition: (ob: T) => ob is S, callback: (ob: S) => T ) => T[] = (list, condition, callback) => list.map(t => (condition(t) ? callback(t) : t))</t,>