Jest/Enzyme Unit Testing: How to pass store to shallow component that uses redux 4 and react-redux 6 connect function

Question

I'm doing as usual some unit tests with jest and enzyme for one new project. I used to test components that were connected to redux in this way:

a) a store generator

import { createStore } from 'redux';

import rootReducer from '../src/reducers';

export const storeFactory = (initialState) => {
   return createStore(rootReducer, initialState);
}

which is consumed by the Input.test.js file

import React from 'react';
import { shallow } from 'enzyme';

import { findByTestAttr,storeFactory } from '../../../test/testUtils';
import Input from './Input';



const setup = (initialState={}) => {
    const store = storeFactory(initialState);
    const wrapper = shallow(
        <Input store={store} />
        ).dive();
    console.log(wrapper.debug());

}

being the example component Input.js:

import React, { Component } from 'react';
import { connect } from 'react-redux';

class Input extends Component {
    render(){
        return <div />;
    }
}

const mapStateToProps = (state) => {
    return {};
}

export default connect(mapStateToProps)(Input);

My npm package versions are:

 "dependencies": {
    "ajv": "^6.6.2",
    "react": "^16.7.0",
    "react-dom": "^16.7.0",
    "react-redux": "^6.0.0",
    "react-scripts": "2.1.3",
    "redux": "^4.0.1"
  }

  "devDependencies": {
    "check-prop-types": "^1.1.2",
    "enzyme": "^3.8.0",
    "enzyme-adapter-react-16": "^1.7.1",
    "jest": "^23.6.0",
    "jest-enzyme": "^7.0.1",
    "prop-types": "^15.6.2"
  }

And that used to work, but I'm getting this message when running the tests on the tests execution report:

Invariant Violation: Passing redux store in props has been removed and does not do anything. To use a custom Redux store for specific components, create a custom React context with React.createContext(), and pass the context object to React-Redux's Provider and specific components like: . You may also pass a {context : MyContext} option to connect

I tried to pass the context as a parameter of shallow

const setup = (initialState={}) => {
    const store = storeFactory(initialState);
    const wrapper = shallow(
        <Input  />, { store }
        );
    console.log(wrapper.debug());

}

But then I get this logged to console

<ContextConsumer>
        [function bound renderWrappedComponent]
      </ContextConsumer>

and if I try to use then enzyme dive() method I get:

const setup = (initialState={}) => {
    const store = storeFactory(initialState);
    const wrapper = shallow(
        <Input  />, { store }
        ).dive();
    console.log(wrapper.debug());

}

Test suite failed to run

TypeError: ShallowWrapper::dive() can only be called on components

Which is the suggested way of doing it now? I know what the message says but before there was no need of wrapping the element into a Provider for jest/enzyme unit tests. Thank you very much!

Answer 1

shallow and dive doesn't work as expected in react-redux 6, so you may want to downgrade it to react-redux 5.0.7 for it to work.

But if you prefer using react-redux 6, then you might want to use mount instead. So, the above code can be rewritten as follows:

Input.test.js

import React from 'react'
import {Provider} from 'react-redux'
import {mount} from 'enzyme'

import {findByAttr, storeFactory} from '../test/testUtils'
import Input from './Input'

const setup = (initialState={}) => {
  const store = storeFactory(initialState)
  const wrapper = mount(<Provider store={store}><Input /></Provider>)
  console.log(wrapper.debug())
}

setup()

Console

    console.log src/Input.test.js:11
      <Provider store={{...}}>
        <Connect(Input)>
          <Input dispatch={[Function: dispatch]}>
            <div />
          </Input>
        </Connect(Input)>
      </Provider>

And there is another workaround if prefer testing the component as unconnected component, you can still use react-redux 6 and use shallow; code can be rewritten as follows:

Add export keyword to Input

Input.js

import React, { Component } from 'react';
import { connect } from 'react-redux';

export class Input extends Component {
    render(){
        return <div />;
    }
}

const mapStateToProps = (state) => {
    return {};
}

export default connect(mapStateToProps)(Input);

Input.test.js

import React from 'react';
import { shallow } from 'enzyme';

import { findByTestAttr } from '../../../test/testUtils';
import { Input } from './Input';



const setup = (props={}) => {
    const wrapper = shallow(<Input {...props} />);
    console.log(wrapper.debug());

}

Console

<div />

Hope this helps!