redux-devtools/extension/test/app/inject/enhancer.spec.js

import '@babel/polyfill';
import { createStore, compose } from 'redux';
import { insertScript, listenMessage } from '../../utils/inject';
import '../../../src/pageScript';

function counter(state = 0, action) {
  switch (action.type) {
    case 'INCREMENT':
      return state + 1;
    case 'DECREMENT':
      return state - 1;
    default:
      return state;
  }
}

describe('Redux enhancer', () => {
  it('should create the store', async () => {
    const message = await listenMessage(() => {
      window.store = createStore(
        counter,
        window.__REDUX_DEVTOOLS_EXTENSION__(),
      );
      expect(typeof window.store).toBe('object');
    });
    expect(message.type).toBe('INIT_INSTANCE');
    expect(window.store.getState()).toBe(0);
    insertScript('window.devToolsOptions = { serialize: false }');
  });

  it('should start monitoring', async () => {
    let message = await listenMessage(() => {
      window.postMessage({ type: 'START', source: '@devtools-extension' }, '*');
    });
    expect(message.type).toBe('START');

    message = await listenMessage();
    expect(message.type).toBe('STATE');
    expect(message.actionsById).toMatch(
      /{"0":{"type":"PERFORM_ACTION","action":{"type":"@@INIT"},"/,
    );
    expect(message.computedStates).toBe('[{"state":0}]');
  });

  it('should perform actions', async () => {
    let message = await listenMessage(() => {
      window.store.dispatch({ type: 'INCREMENT' });
      expect(window.store.getState()).toBe(1);
    });
    expect(message.type).toBe('ACTION');
    expect(message.action).toMatch(
      /{"type":"PERFORM_ACTION","action":{"type":"INCREMENT"},/,
    );
    expect(message.payload).toBe('1');

    message = await listenMessage(() => {
      window.store.dispatch({ type: 'INCREMENT' });
      expect(window.store.getState()).toBe(2);
    });
    expect(message.type).toBe('ACTION');
    expect(message.action).toMatch(
      /{"type":"PERFORM_ACTION","action":{"type":"INCREMENT"},/,
    );
    expect(message.payload).toBe('2');
  });

  it('should dispatch actions remotely', async () => {
    let message = await listenMessage(() => {
      window.postMessage(
        {
          type: 'ACTION',
          payload: "{ type: 'INCREMENT' }",
          source: '@devtools-extension',
        },
        '*',
      );
    });
    expect(message.type).toBe('ACTION');

    message = await listenMessage();
    expect(message.type).toBe('ACTION');
    expect(message.action).toMatch(
      /{"type":"PERFORM_ACTION","action":{"type":"INCREMENT"},/,
    );
    expect(message.payload).toBe('3');
  });

  it('should cancel (toggle) action', async () => {
    let message = await listenMessage(() => {
      window.postMessage(
        {
          type: 'DISPATCH',
          payload: { type: 'TOGGLE_ACTION', id: 1 },
          source: '@devtools-extension',
        },
        '*',
      );
    });
    expect(message.type).toBe('DISPATCH');

    message = await listenMessage();
    expect(message.type).toBe('STATE');
    expect(window.store.getState()).toBe(2);

    message = await listenMessage(() => {
      window.postMessage(
        {
          type: 'DISPATCH',
          payload: { type: 'TOGGLE_ACTION', id: 1 },
          source: '@devtools-extension',
        },
        '*',
      );
    });
    expect(message.type).toBe('DISPATCH');

    message = await listenMessage();
    expect(message.type).toBe('STATE');
    expect(window.store.getState()).toBe(3);
  });

  it('should move back and forward (time travel)', async () => {
    let message = await listenMessage(() => {
      window.postMessage(
        {
          type: 'DISPATCH',
          payload: { type: 'JUMP_TO_STATE', index: 2, actionId: 2 },
          source: '@devtools-extension',
        },
        '*',
      );
    });
    expect(message.type).toBe('DISPATCH');
    expect(window.store.getState()).toBe(2);

    message = await listenMessage(() => {
      window.postMessage(
        {
          type: 'DISPATCH',
          payload: { type: 'JUMP_TO_STATE', index: 3, actionId: 3 },
          source: '@devtools-extension',
        },
        '*',
      );
    });
    expect(message.type).toBe('DISPATCH');
    expect(window.store.getState()).toBe(3);
  });

  it('should import state history', async () => {
    let message = await listenMessage(() => {
      window.postMessage(
        {
          type: 'IMPORT',
          state: JSON.stringify({
            monitorState: {},
            actionsById: {
              0: { type: 'PERFORM_ACTION', action: { type: '@@INIT' } },
              1: { type: 'PERFORM_ACTION', action: { type: 'INCREMENT' } },
              2: { type: 'PERFORM_ACTION', action: { type: 'INCREMENT' } },
            },
            nextActionId: 3,
            stagedActionIds: [0, 1, 2],
            skippedActionIds: [],
            currentStateIndex: 2,
            computedStates: [{ state: 0 }, { state: 1 }, { state: 2 }],
          }),
          source: '@devtools-extension',
        },
        '*',
      );
    });
    expect(message.type).toBe('IMPORT');
    message = await listenMessage();
    expect(message.type).toBe('STATE');
    expect(window.store.getState()).toBe(2);
  });

  it('should create the store with config parameters', async () => {
    const message = await listenMessage(() => {
      window.store = createStore(
        counter,
        window.__REDUX_DEVTOOLS_EXTENSION__({
          actionsDenylist: ['SOME_ACTION'],
        }),
      );
      expect(typeof window.store).toBe('object');
    });
    expect(message.type).toBe('INIT_INSTANCE');
  });

  it('should create the store using old Redux api', async () => {
    const message = await listenMessage(() => {
      window.store =
        window.__REDUX_DEVTOOLS_EXTENSION__()(createStore)(counter);
      expect(typeof window.store).toBe('object');
    });
    expect(message.type).toBe('INIT_INSTANCE');
  });

  it('should create the store with several enhancers', async () => {
    const testEnhancer = (next) => (reducer, initialState, enhancer) =>
      next(reducer, initialState, enhancer);
    const message = await listenMessage(() => {
      window.store = createStore(
        counter,
        compose(testEnhancer, window.__REDUX_DEVTOOLS_EXTENSION__()),
      );
      expect(typeof window.store).toBe('object');
    });
    expect(message.type).toBe('INIT_INSTANCE');
  });
});