redux-mock-store/README.md

A mock store for testing your redux async action creators and middleware

# Deprecation notice

The Redux team does not recommend testing using this library. Instead, see our [docs](https://redux.js.org/usage/writing-tests) for recommended practices, using a real store.

Testing with a mock store leads to potentially confusing behaviour, such as state not updating when actions are dispatched. Additionally, it's a lot less useful to assert on the actions dispatched rather than the observable state changes.

You can test the entire combination of action creators, reducers, and selectors in a single test, for example:

```js
it('should add a todo', () => {
  const store = makeStore() // a user defined reusable store factory

  store.dispatch(addTodo('Use Redux'))

  expect(selectTodos(store.getState())).toEqual([
    { text: 'Use Redux', completed: false }
  ])
})
```

This avoids common pitfalls of testing each of these in isolation, such as mocked state shape becoming out of sync with the actual application.

# redux-mock-store [![Circle CI](https://circleci.com/gh/arnaudbenard/redux-mock-store/tree/master.svg?style=svg)](https://circleci.com/gh/arnaudbenard/redux-mock-store/tree/master)

![npm](https://nodei.co/npm/redux-mock-store.png?downloads=true&downloadRank=true&stars=true)

A mock store for testing Redux async action creators and middleware. The mock store will create an array of dispatched actions which serve as an action log for tests.

Please note that this library is designed to test the action-related logic, not the reducer-related one. In other words, it does not update the Redux store. If you want a complex test combining actions and reducers together, take a look at other libraries (e.g., [redux-actions-assertions](https://github.com/redux-things/redux-actions-assertions)). Refer to issue [#71](https://github.com/arnaudbenard/redux-mock-store/issues/71) for more details.

## Install

```bash
npm install redux-mock-store --save-dev
```

Or

```bash
yarn add redux-mock-store --dev
```

## Usage

### Synchronous actions

The simplest usecase is for synchronous actions. In this example, we will test if the `addTodo` action returns the right payload. `redux-mock-store` saves all the dispatched actions inside the store instance. You can get all the actions by calling `store.getActions()`. Finally, you can use any assertion library to test the payload.

```js
import configureStore from 'redux-mock-store' //ES6 modules
const { configureStore } = require('redux-mock-store') //CommonJS

const middlewares = []
const mockStore = configureStore(middlewares)

// You would import the action from your codebase in a real scenario
const addTodo = () => ({ type: 'ADD_TODO' })

it('should dispatch action', () => {
  // Initialize mockstore with empty state
  const initialState = {}
  const store = mockStore(initialState)

  // Dispatch the action
  store.dispatch(addTodo())

  // Test if your store dispatched the expected actions
  const actions = store.getActions()
  const expectedPayload = { type: 'ADD_TODO' }
  expect(actions).toEqual([expectedPayload])
})
```

### Asynchronous actions

A common usecase for an asynchronous action is a HTTP request to a server. In order to test those types of actions, you will need to call `store.getActions()` at the end of the request.

```js
import configureStore from 'redux-mock-store'
import thunk from 'redux-thunk'

const middlewares = [thunk] // add your middlewares like `redux-thunk`
const mockStore = configureStore(middlewares)

// You would import the action from your codebase in a real scenario
function success() {
  return {
    type: 'FETCH_DATA_SUCCESS'
  }
}

function fetchData() {
  return (dispatch) => {
    return fetch('/users.json') // Some async action with promise
      .then(() => dispatch(success()))
  }
}

it('should execute fetch data', () => {
  const store = mockStore({})

  // Return the promise
  return store.dispatch(fetchData()).then(() => {
    const actions = store.getActions()
    expect(actions[0]).toEqual(success())
  })
})
```

### API

```js
configureStore(middlewares?: Array) => mockStore: Function
```

Configure mock store by applying the middlewares.

```js
mockStore(getState?: Object,Function) => store: Function
```

Returns an instance of the configured mock store. If you want to reset your store after every test, you should call this function.

```js
store.dispatch(action) => action
```

Dispatches an action through the mock store. The action will be stored in an array inside the instance and executed.

```js
store.getState() => state: Object
```

Returns the state of the mock store.

```js
store.getActions() => actions: Array
```

Returns the actions of the mock store.

```js
store.clearActions()
```

Clears the stored actions.

```js
store.subscribe(callback: Function) => unsubscribe: Function
```

Subscribe to the store.

```js
store.replaceReducer(nextReducer: Function)
```

Follows the Redux API.

### Old version (`< 1.x.x`)

https://github.com/arnaudbenard/redux-mock-store/blob/v0.0.6/README.md

### Versions

The following versions are exposed by redux-mock-store from the `package.json`:

- `main`: commonJS Version
- `module`/`js:next`: ES Module Version
- `browser` : UMD version

## License

The MIT License