Enzyme Jest React Redux Connected Component in Typescript

Question

Background There are numerous examples online for testing react-redux higher order components, eg: react Components using connect(). However, they are all in ES6. I understand the structure and able to run the tests with the help of these docs or examples.

Issue When I try to use the JS code and translate it into Typescritpt, I start getting type issues. Not really sure how this could be done in typescript

The component I'm trying to test is Counter component tha in the AspNetCore React-Redux yoman scaffold

Counter.tsx

import * as React from 'react';
import { Link, RouteComponentProps } from 'react-router-dom';
import { connect } from 'react-redux';
import { ApplicationState }  from '../store';
import * as CounterStore from '../store/Counter';
import * as WeatherForecasts from '../store/WeatherForecasts';

type CounterProps =
     CounterStore.CounterState
     & typeof CounterStore.actionCreators
     & RouteComponentProps<{}>;

export class Counter extends React.Component<CounterProps, {}> {
    public render() {
    return <div>
        <h1>Counter</h1>

        <p>This is a simple example of a React component.</p>

        <p>Current count: <strong>{ this.props.count }</strong></p>

        <button onClick={
        () => { this.props.increment() }
        }>Increment</button>
    </div>;
    }
}

export default connect(
    (state: ApplicationState) => state.counter,
CounterStore.actionCreators                 
)(Counter) as typeof Counter;

Counter.spec.js

import { Counter} from '../../ClientApp/components/Counter;
import * as Provider from 'react-redux';
import configureMockStore from 'redux-mock-store';
import * as store from '../../ClientApp/store';
import { shallow, mount } from 'enzyme';

declare var describe, beforeEach, it, expect, state, stub;

describe('Counter', () => {
    let wrapper;

    beforeEach(() => {
        wrapper = shallow(<Provider store={store}>
             <Counter />
        </Provider>
    )
});

    it('render Counter', () => {
    expect(wrapper.length).toEqual(1)
    });
});

Error Messages

[ts] JSX element type 'Provider' does not have any construct or call signatures.
[ts] 'React' refers to a UMD global, but the current file is a module. Consider adding an import instead
[ts]
Type '{}' is not assignable to type 'IntrinsicAttributes &  IntrinsicClassAttributes<Login> & Readonly<{ children?: ReactNode; }> & Rea...'.
Type '{}' is not assignable to type 'Readonly<UserProps>'.
    Property 'loggedIn' is missing in type '{}'.

Question

How to get rid of these error messaes

Answer 1

you forgot to import React in your spec file:

import * as React from 'react' // -------------------------------> THIS LINE
import { Counter} from '../../ClientApp/components/Counter;
import * as Provider from 'react-redux';
import configureMockStore from 'redux-mock-store';
import * as store from '../../ClientApp/store';
import { shallow, mount } from 'enzyme';

declare var describe, beforeEach, it, expect, state, stub;

describe('Counter', () => {
    let wrapper;

    beforeEach(() => {
        wrapper = shallow(<Provider store={store}>
             <Counter />
        </Provider>
    )
});

    it('render Counter', () => {
    expect(wrapper.length).toEqual(1)
    });
});