模拟 store.getState()

Question

我想断言，当一个函数使用 store.getState() 获取我的 redux 状态值时，它会根据该状态的条件执行各种操作。我如何使用store.getState() 方法断言/模拟我希望某些测试的状态值是什么？谢谢。

sampleFunction.js：

import { store } from './reduxStore';

const sampleFunction = () => {
  const state = store.getState();
  let result = false;
  if (state.foo.isGood) {
    result = true;
  }

  return result;
};

export default sampleFunction;

sampleFunction.test.js：

import sampleFunction from './sampleFunction.js';

test('sampleFunction returns true', () => {
  // assert that state.foo.isGood = true
  expect(sampleFunction()).toBeTruthy();
});

Answer 1

你可以做些什么来模拟你的商店

import { store } from './reduxStore';
import sampleFunction from './sampleFunction.js';

jest.mock('./reduxStore')

const mockState = {
  foo: { isGood: true }
}

// in this point store.getState is going to be mocked
store.getState = () => mockState

test('sampleFunction returns true', () => {
  // assert that state.foo.isGood = true
  expect(sampleFunction()).toBeTruthy();
});

Answer 2

import { store } from './reduxStore';
import sampleFunction from './sampleFunction.js';


beforeAll(() => {
jest.mock('./reduxStore')

const mockState = {
  foo: { isGood: true }
}

 // making getState as mock function and returning mock value
 store.getState = jest.fn().mockReturnValue(mockState)

});

afterAll(() => {
 jest.clearAllMocks();
 jest.resetAllMocks();
});

test('sampleFunction returns true', () => {
  // assert that state.foo.isGood = true
  expect(sampleFunction()).toBeTruthy();
});