Jest:模拟高阶函数

// applyFunction.js
function applyFunction(fn, a, b) {
  return fn(a, b);
}

module.exports = applyFunction;

// applyFunction.test.js
const applyFunction = require("./applyFunction");

describe("applyFunction", () => {
  const mockFunction = jest.fn((a, b) => a + b);

  it("should call the given function with the provided arguments and return the result", () => {
    const result = applyFunction(mockFunction, 1, 2);
    expect(mockFunction).toHaveBeenCalledWith(1, 2);
    expect(result).toBe(3);
  });
});