下面的单元测试解决方案在不使用模拟 redux 存储的情况下模拟useDispatch钩子和next/routermodule。使用模拟的 redux store 并在调度 action 后检查 store 的状态更接近于集成测试。
例如
index.jsx:
import React, { useEffect } from 'react';
import Router from 'next/router';
import { useDispatch } from 'react-redux';
import { logout } from './user.actions';
import { LoadingMessage } from './LoadingMessage';
export const Logout = () => {
const dispatch = useDispatch();
const props = {
active: true,
withOverlay: false,
small: false,
};
useEffect(() => {
dispatch(logout());
Router.push('/');
}, []);
return (
<div>
<LoadingMessage {...props}>
<div>Logging out, please wait...</div>
</LoadingMessage>
</div>
);
};
user.actions.ts:
export function logout() {
return {
type: 'LOGOUT',
};
}
LoadingMessage.jsx
export const LoadingMessage = ({ children }) => <div>{children}</div>;
index.test.jsx:
import { Logout } from './';
import { useDispatch } from 'react-redux';
import { mount } from 'enzyme';
import Router from 'next/router';
jest.mock('next/router', () => ({ push: jest.fn() }), { virtual: true });
jest.mock('react-redux', () => {
const originalReactRedux = jest.requireActual('react-redux');
const mDispatch = jest.fn();
const mUseDispatch = jest.fn(() => mDispatch);
return {
...originalReactRedux,
useDispatch: mUseDispatch,
};
});
describe('61928263', () => {
afterEach(() => {
jest.clearAllMocks();
});
afterAll(() => {
jest.resetAllMocks();
});
it('should pass without using mock store', () => {
const wrapper = mount(<Logout></Logout>);
expect(wrapper.find('LoadingMessage')).toBeTruthy();
expect(useDispatch).toBeCalledTimes(1);
const mDispatch = useDispatch(); // get the mocked dispatch function
expect(mDispatch).toBeCalledWith({ type: 'LOGOUT' });
expect(Router.push).toBeCalledWith('/');
});
});
测试结果:
PASS stackoverflow/61928263/index.test.jsx (8.62s)
61928263
✓ should pass without using mock store (37ms)
--------------------|---------|----------|---------|---------|-------------------
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
--------------------|---------|----------|---------|---------|-------------------
All files | 100 | 100 | 100 | 100 |
LoadingMessage.jsx | 100 | 100 | 100 | 100 |
index.jsx | 100 | 100 | 100 | 100 |
user.actions.ts | 100 | 100 | 100 | 100 |
--------------------|---------|----------|---------|---------|-------------------
Test Suites: 1 passed, 1 total
Tests: 1 passed, 1 total
Snapshots: 0 total
Time: 9.601s