如何用jest测试combineReducers

Question

我正在尝试测试combineReducers，但得到的错误如下。

TypeError：_testReducer.testReducer.test11不是函数

以下是减速机

// testReducer.js
import { combineReducers } from "redux-immutable";
const test11 = (state, action) => {
 switch (action.type) {
    case "temp11":
      return true;
    default:
      return state;
  }
};
const test22 = (state, action) => {
 switch (action.type) {
    case "temp22":
      return false;
    default:
      return state;
  }
};
export const testReducer = combineReducers({
  test11,
  test22,
});

下面是测试用例

// testReducer.test.js
import { testReducer } from "./testReducer.js";
describe("test for testReducer", () => {
  it("test11", () => {
    const returnTrueValue = true;
    expect(
      testReducer.test11(
        true, {
          type: "temp11",
        }
      )
    ).toEqual(returnTrueValue);
  });
  it("test11", () => {
    const returnFalseValue = false;
    expect(
      testReducer.test22(
        true, {
          type: "temp22",
        }
      )
    ).toEqual(returnFalseValue);
  });
});

如果我导出还原器中的所有函数，并在测试用例中导入单个函数，它就能工作，但这并不是理想的情况。

Answer 1

combineReducers返回一个函数，该函数合并了您输入的所有还原器的状态。它不允许您访问单个减速机并单独调用它们。

你应该把它用在你的案子上：

expect(
    testReducer(true, {type: "temp11"}).test11
).toEqual(returnTrueValue);

Answer 2

我假设组件减速器如下所示：

export const initialState = {
  totalValue: 0
};

const DashboardReducer = (state = initialState, action: any)=> {
  switch(action.type) {
    case 'case1':
     .......
     .......
     .......
    default:
      return state;
 }

我假设根还原器如下所示：

export const rootReducer = combineReducers({
  dashboard: DashboardReducer
});

测试文件应该如下所示：

import { rootReducer } from './root.reducer';
import { createStore } from 'redux';
import { initialState as dashboardState } from './modules/uv_dashboard/uv_dashboard.reducer';

describe('Root Reducer Suite', () => {

  let store = createStore(rootReducer)

  test('loaded correctly', () => {
    expect(store.getState().dashboard).toEqual(dashboardState);
  });
});