Jasmine：监视由另一个函数调用的导出函数不起作用

Question

我已经创建了 2 个辅助函数，其中一个是第一个的快捷方式，在我的测试中我想验证这个函数是否被调用，这些函数在同一个文件中：

export function test1(param1, param2, param3, param4) {
    return { param1, param2, ...(param3 && { param3 }), ...(param4 && { param4 }) };
}

export function test2(param1, param2) {
    return test1(param1, null, null, param2);
}

在测试中我需要证明第一个被第二个调用：

import * as Util from './my-util-file';
const test2 = Util.test2;
...
it('should call test1 when test2 is called', () => {
    const test1 = spyOn(Util, 'test1').and.callThrough();
    test2('test', 1);
    expect(test1).toHaveBeenCalledWith('test', null, null, 1);
});

或

import {test1, test2} from './my-util-file';
...
it('should call test1 when test2 is called', () => {
    const test1Spy = jasmine.createSpy('test1');
    test2('test', 1);
    expect(test1Spy).toHaveBeenCalledWith('test', null, null, 1);
});

或

import * as Util from './my-util-file';
const test2 = Util.test2;

...
it('should call test1 when test2 is called', () => {
    const test1Spy = spyOnProperty(Util, 'test1');
    test2('test', 1);
    expect(test1Spy).toHaveBeenCalledWith('test', null, null, 1);
});

或

import {test1, test2} from './my-util-file';

...
it('should call test1 when test2 is called', () => {
    const test1Spy = spyOn(window as any, 'test1');
    test2('test', 1);
    expect(test1Spy).toHaveBeenCalledWith('test', null, null, 1);
});

但问题是我得到了错误：

Expected spy test1 to have been called.

Answer 1

这不是茉莉花的问题。这就是 javascript 模块在 compiled/transpiled.

时的行为方式

var test1 = function test1() {};
var test2 = function test2() { test1(); };

exports.test1 = test1;
exports.test2 = test2;

当声明函数test2时，对test1函数的引用被包含在函数声明中。但在规范中，我们真正导入的是 exports.test1 && exports.test2。所以基本上我们正在监视一些不想要的东西，即 exports.test1.

因此，为了保持引用，我们可以定义并导出测试函数，如下所示：

const test1 = function(param1: any, param2: any, param3: any, param4: any) {
  return { 
    param1,
    param2,
    ...(param3 && { param3 }),
    ...(param4 && { param4 })
  };
};

const test2 = function(param1: any, param2: any) { 
  return testFunctions.test1(param1, null, null, param2); //Here we are attaching the refernce
};

export const testFunctions = {
  test1,
  test2
};

我们可以如下测试它们：

import * as test from './test';

const functions = test.testFunctions;

it('should call test1 when test2 is called', () => {
    const test1 = spyOn(functions, 'test1').and.callThrough();
    functions.test2('test', 1);
    expect(test1).toHaveBeenCalledWith('test', null, null, 1);
});

很好的article解释了上面的问题，供大家参考

Jasmine：监视由另一个函数调用的导出函数不起作用

Jasmine : Spying an exported function that is called by an another function doesn't work

jasmine

typescript

karma-jasmine

angular