1
这里的功能是我moduleA.ts
:玩笑,戏弄不工作
我想嘲笑genName
功能和测试getMessage
功能
const getMessage =(): string => {
return `Her name is ${genName()}`;
};
function genName(): string {
return Math.random() > 0.5 ? 'emilie' : 'novaline';
}
export default {
getMessage,
genName
}
这里是我的测试文件:
import moduleA from '../moduleA';
moduleA.genName = jest.fn(() => 'mrdulin');
describe('mock function',() => {
it('t-0',() => {
expect(jest.isMockFunction(moduleA.genName)).toBeTruthy();
expect(moduleA.genName()).toBe('mrdulin');
});
it('t-0.5',() => {
expect(jest.isMockFunction(moduleA.genName)).toBeTruthy();
});
it('t-1',() => {
expect(moduleA.getMessage()).toBe('Her name is emilie');
expect(moduleA.genName).toHaveBeenCalled()
});
});
但它似乎不是模拟genName
功能成功:
FAIL jest-examples/__test__/mock-function-0.spec.ts
● mock function › t-1
expect(received).toBe(expected)
Expected value to be (using ===):
"Her name is emilie"
Received:
"Her name is novaline"
at Object.it (jest-examples/__test__/mock-function-0.spec.ts:18:34)
at Promise.resolve.then.el (node_modules/p-map/index.js:42:16)
at process._tickCallback (internal/process/next_tick.js:109:7)
mock function
✓ t-0 (3ms)
✓ t-0.5
✕ t-1 (14ms)
Test Suites: 1 failed, 1 total
Tests: 1 failed, 2 passed, 3 total
Snapshots: 0 total
Time: 0.152s, estimated 1s
Ran all test suites related to changed files.
但我确定已调用moduleA.genName
函数。
PASS jest-examples/__test__/mock-function-0.spec.ts
mock function
✓ t-0 (2ms)
✓ t-0.5 (1ms)
✓ t-1 (1ms)
Test Suites: 1 passed, 1 total
Tests: 3 passed, 3 total
Snapshots: 0 total
Time: 0.148s, estimated 1s
Ran all test suites related to changed files.
合理的问题表示,但让我们假设一个通用的解决方案可能从长远来看更有用。 –
好吧然后答案是,你应该只嘲笑外部依赖,你不应该模拟你想测试的模块的一部分。 –
我不得不不同意 - 如果一个模块使用公开暴露的内部函数,我不明白这个问题是什么 - 这就是单元测试的重点:测试孤立的功能。方法使用的“外部”功能在同一模块中似乎与我无关。你能帮我理解吗? –