这是我的callnapply.js文件

const callAndApply = {
  caller(object, method, nameArg, ageArg, tShirtSizeArg) {
    method.call(object, nameArg, ageArg, tShirtSizeArg);
  },
  applier(object, method, argumentsArr) {
    method.apply(object, argumentsArr);
  },
};
module.exports = callAndApply;

这是测试文件的片段,其中包含无效的测试：

const callnapply = require('./callnapply');

test('testing Function.prototype.call as mock function', () => {
    const outer = jest.fn(); 
    const name = 'Aakash';
    const age = 22;
    const tee = 'M';
    callnapply.caller(this, outer, name, age, tee);
    expect(outer.call).toHaveBeenCalledWith(name, age, tee);
});

如何编写测试以检查我传递的方法是否实际上仅由Function.prototype.call函数调用？我想检查.call()是否被调用,而不是为方法调用编写的其他实现.

解决方法:

您可以模拟.call()方法本身：

const outer = function() {}
outer.call = jest.fn()

然后,您可以对external.call进行通常的笑话模拟测试.

这是工作测试文件：

const callnapply = require('./callnapply');

test('testing Function.prototype.call as mock function', () => {
    const outer = function() {};
    outer.call = jest.fn();
    const name = 'Aakash';
    const age = 22;
    const tee = 'M';
    callnapply.caller(this, outer, name, age, tee);
    expect(outer.call).toHaveBeenCalledWith(this, name, age, tee);
});

参见this working REPL.