React 16 componentDidCatch Jest/Enzyme unit test

ErrorBoundary.jsx

import React from 'react'
import PropTypes from 'prop-types'

class ErrorBoundary extends React.Component {
  constructor (props) {
    super(props)
    this.state = { hasError: false }
  }

  componentDidCatch (error, info) {
    console.log(error)
    this.setState({ hasError: true })
  }

  render () {
    if (this.state.hasError) {
      return null
    }
    return this.props.children
  }
}

ErrorBoundary.propTypes = {
  children: PropTypes.object
}

export default ErrorBoundary

ErrorBoundary.spec.js

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

import ErrorBoundary from './ErrorBoundary'

describe('When no JS errors are caught in a child component', () => {
  let ErrorBoundaryComponent

  beforeAll(() => {
    ErrorBoundaryComponent = shallow(<ErrorBoundary><h1>wassup</h1></ErrorBoundary>)
  })

  it('should render the child component', () => {
    expect(ErrorBoundaryComponent.find('h1').exists()).toBeTruthy()
  })
})

describe('When a JS error is caught in a child component', () => {
  let ErrorBoundaryComponent

  beforeAll(() => {
    jest.spyOn(global.console, 'log')
    ErrorBoundaryComponent = shallow(<ErrorBoundary><h1>wassup</h1></ErrorBoundary>)
    ErrorBoundaryComponent.instance().componentDidCatch('oh nooos an error')
    ErrorBoundaryComponent.update()
  })

  it('should log an error to console', () => {
    expect(global.console.log).toHaveBeenCalledWith('oh nooos an error')
  })

  it('should update the state to indicate an error', () => {
    expect(ErrorBoundaryComponent.instance().state.hasError).toBeTruthy()
  })

  it('should not render the child component', () => {
    expect(ErrorBoundaryComponent.find('h1').exists()).toBeFalsy()
  })
})