How do I unit test Redux actions and reducers?

How do I unit test Redux actions and reducers?

To unit test Redux actions, you can use a testing library like Jest. For reducers, you can test the output based on different action types.

Can you show me an example of testing a reducer?

Sure! Here's a simple example:

import reducer from './reducer';
import { ADD_TODO } from './actionTypes';

test('should handle ADD_TODO', () => {
  const initialState = [];
  const action = { type: ADD_TODO, payload: 'Learn Redux' };
  const newState = reducer(initialState, action);
  expect(newState).toEqual(['Learn Redux']);
});

What about testing asynchronous actions?

For asynchronous actions, you can use middleware like Redux Thunk and test it with a library like redux-mock-store. You can mock the store and dispatch actions to test the flow.

Are there any best practices for unit testing in Redux?

Yes! Some best practices include keeping tests isolated, using descriptive test names, and testing both action creators and reducers thoroughly.