branch v2-21-2

  // ****   Search.js   ****
...

// at the end:
const mapStateToProps = (state) => {
  return {
    searchTerm: state.searchTerm
  }
}

// 1. ++++ the typical solution
// this is for testing purposes
export const Unwrapped = Search

// connect expects Redux to be there
export default connect(mapStateToProps)(Search)

Now, import unwrapped into the spec and use instead of ​search​ (which relies on Redux). 

  // ****   Search.spec.js   ****

import React from 'react'
import { shallow } from 'enzyme'
import { shallowToJson } from 'enzyme-to-json'
// 1. ++++ do the import
import Search, { Unwrapped as UnwrappedSearch } from './Search'
import ShowCard from './ShowCard'
import preload from '../public/data.json'

test('Search snapshot test', () => {
  // 2. ++++ then use UnwrappedSearch everywhere
  // pass to this what Redux would have passed it
  // (shows={preload.shows} searchTerm='') ← replace Redux ↴
  const component = shallow(<UnwrappedSearch shows={preload.shows} searchTerm='' />)
  const tree = shallowToJson(component)
  expect(tree).toMatchSnapshot()
})

test('Search should render a ShowCard for each show', () => {
  // 2. ++++ then use UnwrappedSearch everywhere
  const component = shallow(<UnwrappedSearch searchTerm='' shows={preload.shows} />)
  expect(component.find(ShowCard).length).toEqual(preload.shows.length)
})

test('Search should render correct amount of shows based on search', () => {
  const searchWord = 'house'
  store.dispatch(setSearchTerm(searchWord))
  const component = render(<Provider store={store}><Search shows={preload.shows} /></Provider>)
  const showCount = preload.shows.filter((show) => `${show.title} ${show.description}`.toUpperCase().indexOf(searchWord.toUpperCase()) >= 0).length
  expect(component.find('.show-card').length).toEqual(showCount)
})

The test fails, but just because since the last snapshot, we've abstracted out the Header. We can create a new snapshot to accept the change. (At this point he uncommented the last two tests)

  // ****   Search.spec.js   ****

import React from 'react'
// 1. ++++ import Provider
import { Provider } from 'react-redux'
// 3. ++++ also get render (to get the extra depth)
import { shallow, render } from 'enzyme'
import { shallowToJson } from 'enzyme-to-json'
// 2. ++++ import store and setSearchTerm
import store from './store'
import { setSearchTerm } from './actionCreators'
// 3. ++++ also get Search
import Search, { Unwrapped as UnwrappedSearch } from './Search'
import ShowCard from './ShowCard'
import preload from '../public/data.json'

test('Search snapshot test', () => {
  const component = shallow(<UnwrappedSearch shows={preload.shows} searchTerm='' />)
  const tree = shallowToJson(component)
  expect(tree).toMatchSnapshot()
})

// use UnwrappedSearch here too
test('Search should render a ShowCard for each show', () => {
  const component = shallow(<UnwrappedSearch searchTerm='' shows={preload.shows} />)
  expect(component.find(ShowCard).length).toEqual(preload.shows.length)
})

// 4. ++-- first uncomments this test
test('Search should render correct amount of shows based on search', () => {
  const searchWord = 'house'
  // use store ↴
  // basically we're dispaptching an action to the store
  // and testing the result of that
  store.dispatch(setSearchTerm(searchWord))
  const component = render(<Provider store={store}><Search shows={preload.shows} /></Provider>)
  const showCount = preload.shows.filter((show) => `${show.title} ${show.description}`.toUpperCase().indexOf(searchWord.toUpperCase()) >= 0).length
  // just use the CSS class as selector ↴
  expect(component.find('.show-card').length).toEqual(showCount)
})

branch v2-22

  //  ****  reducers.spec.js    ****

import reducers from './reducers'

test('@@INIT', () => {
  let state
  state = reducers(undefined, {})
  expect(state).toEqual({searchTerm: '', omdbData: {}})
})

test('SET_SEARCH_TERM', () => {
  let state
  state = reducers({searchTerm: '', omdbData: {}}, {type: 'SET_SEARCH_TERM', searchTerm: 'house'})
  expect(state).toEqual({searchTerm: 'house', omdbData: {}})
})

test('ADD_OMDB_DATA', () => {
  let state
  state = reducers({searchTerm:'',omdbData:{}}, {type:'ADD_OMDB_DATA',imdbID:'tt3986586',omdbData:{Title:'Fuller House',Year:'2016–',Rated:'TV-G',Released:'26 Feb 2016',Runtime:'30 min',Genre:'Comedy, Family',Director:'N/A',Writer:'Jeff Franklin',Actors:'Candace Cameron Bure, Jodie Sweetin, Andrea Barber, Michael Campion',Plot:'In a continuation of Full House, D.J. Fuller is a mother of three young boys and is a recent widow. D.J.\'s sister Stephanie, her best friend Kimmy and Kimmy\'s teenage daughter all move in to help raise her sons. The house is now a lot fuller.',Language:'English',Country:'USA',Awards:'1 win.',Poster:'https://images-na.ssl-images-amazon.com/images/M/MV5BMTU2NzA0ODAyMF5BMl5BanBnXkFtZTgwNDE5MTIxMDI@._V1_SX300.jpg',Metascore:'N/A',imdbRating:'7.2',imdbVotes:'13,415',imdbID:'tt3986586',Type:'series',totalSeasons:'2',Response:'True'}})
  expect(state).toEqual({searchTerm:'',omdbData:{tt3986586:{Title:'Fuller House',Year:'2016–',Rated:'TV-G',Released:'26 Feb 2016',Runtime:'30 min',Genre:'Comedy, Family',Director:'N/A',Writer:'Jeff Franklin',Actors:'Candace Cameron Bure, Jodie Sweetin, Andrea Barber, Michael Campion',Plot:'In a continuation of Full House, D.J. Fuller is a mother of three young boys and is a recent widow. D.J.\'s sister Stephanie, her best friend Kimmy and Kimmy\'s teenage daughter all move in to help raise her sons. The house is now a lot fuller.',Language:'English',Country:'USA',Awards:'1 win.',Poster:'https://images-na.ssl-images-amazon.com/images/M/MV5BMTU2NzA0ODAyMF5BMl5BanBnXkFtZTgwNDE5MTIxMDI@._V1_SX300.jpg',Metascore:'N/A',imdbRating:'7.2',imdbVotes:'13,415',imdbID:'tt3986586',Type:'series',totalSeasons:'2',Response:'True'}}})
})

He usually doesn't test actionCreators and thunks.