docs: add test example for context. (#60)

* Add Test and add myself to list of contributors

* Change getByTestId to getByText

* Chage how value is set on Provider because it is better on performance

* Add test to list of examples in README

Author: ChrisWcs

.all-contributorsrc

@@ -186,6 +186,15 @@
       "contributions": [
         "doc"
       ]
+    },
+    {
+      "login": "ChrisWcs",
+      "name": "Christian",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/19828824?v=4",
+      "profile": "http://Chriswcs.github.io",
+      "contributions": [
+        "test"
+      ]
     }
   ]
 }

README.md

@@ -16,7 +16,7 @@
 [![downloads][downloads-badge]][npmtrends]
 [![MIT License][license-badge]][license]
 
-[![All Contributors](https://img.shields.io/badge/all_contributors-18-orange.svg?style=flat-square)](#contributors)
+[![All Contributors](https://img.shields.io/badge/all_contributors-19-orange.svg?style=flat-square)](#contributors)
 [![PRs Welcome][prs-badge]][prs]
 [![Code of Conduct][coc-badge]][coc]
 
@@ -456,6 +456,7 @@ Some included are:
 
 * [`react-redux`](https://github.com/kentcdodds/react-testing-library/blob/master/src/__tests__/react-redux.js)
 * [`react-router`](https://github.com/kentcdodds/react-testing-library/blob/master/src/__tests__/react-router.js)
+* [`react-context`](https://github.com/kentcdodds/react-testing-library/blob/master/src/__tests__/react-context.js)
 
 Examples of TDD with react-testing-library:
 
@@ -753,13 +754,11 @@ light-weight, simple, and understandable.
 Thanks goes to these people ([emoji key][emojis]):
 
 <!-- ALL-CONTRIBUTORS-LIST:START - Do not remove or modify this section -->
-
 <!-- prettier-ignore -->
 | [<img src="https://avatars.githubusercontent.com/u/1500684?v=3" width="100px;"/><br /><sub><b>Kent C. Dodds</b></sub>](https://kentcdodds.com)<br />[💻](https://github.com/kentcdodds/react-testing-library/commits?author=kentcdodds "Code") [📖](https://github.com/kentcdodds/react-testing-library/commits?author=kentcdodds "Documentation") [🚇](#infra-kentcdodds "Infrastructure (Hosting, Build-Tools, etc)") [⚠️](https://github.com/kentcdodds/react-testing-library/commits?author=kentcdodds "Tests") | [<img src="https://avatars1.githubusercontent.com/u/2430381?v=4" width="100px;"/><br /><sub><b>Ryan Castner</b></sub>](http://audiolion.github.io)<br />[📖](https://github.com/kentcdodds/react-testing-library/commits?author=audiolion "Documentation") | [<img src="https://avatars0.githubusercontent.com/u/8008023?v=4" width="100px;"/><br /><sub><b>Daniel Sandiego</b></sub>](https://www.dnlsandiego.com)<br />[💻](https://github.com/kentcdodds/react-testing-library/commits?author=dnlsandiego "Code") | [<img src="https://avatars2.githubusercontent.com/u/12592677?v=4" width="100px;"/><br /><sub><b>Paweł Mikołajczyk</b></sub>](https://github.com/Miklet)<br />[💻](https://github.com/kentcdodds/react-testing-library/commits?author=Miklet "Code") | [<img src="https://avatars3.githubusercontent.com/u/464978?v=4" width="100px;"/><br /><sub><b>Alejandro Ñáñez Ortiz</b></sub>](http://co.linkedin.com/in/alejandronanez/)<br />[📖](https://github.com/kentcdodds/react-testing-library/commits?author=alejandronanez "Documentation") | [<img src="https://avatars0.githubusercontent.com/u/1402095?v=4" width="100px;"/><br /><sub><b>Matt Parrish</b></sub>](https://github.com/pbomb)<br />[🐛](https://github.com/kentcdodds/react-testing-library/issues?q=author%3Apbomb "Bug reports") [💻](https://github.com/kentcdodds/react-testing-library/commits?author=pbomb "Code") [📖](https://github.com/kentcdodds/react-testing-library/commits?author=pbomb "Documentation") [⚠️](https://github.com/kentcdodds/react-testing-library/commits?author=pbomb "Tests") | [<img src="https://avatars1.githubusercontent.com/u/1288694?v=4" width="100px;"/><br /><sub><b>Justin Hall</b></sub>](https://github.com/wKovacs64)<br />[📦](#platform-wKovacs64 "Packaging/porting to new platform") |
 | :---: | :---: | :---: | :---: | :---: | :---: | :---: |
 | [<img src="https://avatars1.githubusercontent.com/u/1241511?s=460&v=4" width="100px;"/><br /><sub><b>Anto Aravinth</b></sub>](https://github.com/antoaravinth)<br />[💻](https://github.com/kentcdodds/react-testing-library/commits?author=antoaravinth "Code") [⚠️](https://github.com/kentcdodds/react-testing-library/commits?author=antoaravinth "Tests") [📖](https://github.com/kentcdodds/react-testing-library/commits?author=antoaravinth "Documentation") | [<img src="https://avatars2.githubusercontent.com/u/3462296?v=4" width="100px;"/><br /><sub><b>Jonah Moses</b></sub>](https://github.com/JonahMoses)<br />[📖](https://github.com/kentcdodds/react-testing-library/commits?author=JonahMoses "Documentation") | [<img src="https://avatars1.githubusercontent.com/u/4002543?v=4" width="100px;"/><br /><sub><b>Łukasz Gandecki</b></sub>](http://team.thebrain.pro)<br />[💻](https://github.com/kentcdodds/react-testing-library/commits?author=lgandecki "Code") [⚠️](https://github.com/kentcdodds/react-testing-library/commits?author=lgandecki "Tests") [📖](https://github.com/kentcdodds/react-testing-library/commits?author=lgandecki "Documentation") | [<img src="https://avatars2.githubusercontent.com/u/498274?v=4" width="100px;"/><br /><sub><b>Ivan Babak</b></sub>](https://sompylasar.github.io)<br />[🐛](https://github.com/kentcdodds/react-testing-library/issues?q=author%3Asompylasar "Bug reports") [🤔](#ideas-sompylasar "Ideas, Planning, & Feedback") | [<img src="https://avatars3.githubusercontent.com/u/4439618?v=4" width="100px;"/><br /><sub><b>Jesse Day</b></sub>](https://github.com/jday3)<br />[💻](https://github.com/kentcdodds/react-testing-library/commits?author=jday3 "Code") | [<img src="https://avatars0.githubusercontent.com/u/15199?v=4" width="100px;"/><br /><sub><b>Ernesto García</b></sub>](http://gnapse.github.io)<br />[💬](#question-gnapse "Answering Questions") [💻](https://github.com/kentcdodds/react-testing-library/commits?author=gnapse "Code") [📖](https://github.com/kentcdodds/react-testing-library/commits?author=gnapse "Documentation") | [<img src="https://avatars2.githubusercontent.com/u/2747424?v=4" width="100px;"/><br /><sub><b>Josef Maxx Blake</b></sub>](http://jomaxx.com)<br />[💻](https://github.com/kentcdodds/react-testing-library/commits?author=jomaxx "Code") [📖](https://github.com/kentcdodds/react-testing-library/commits?author=jomaxx "Documentation") [⚠️](https://github.com/kentcdodds/react-testing-library/commits?author=jomaxx "Tests") |
-| [<img src="https://avatars1.githubusercontent.com/u/29602306?v=4" width="100px;"/><br /><sub><b>Michal Baranowski</b></sub>](https://twitter.com/baranovskim)<br />[📝](#blog-mbaranovski "Blogposts") [✅](#tutorial-mbaranovski "Tutorials") | [<img src="https://avatars3.githubusercontent.com/u/13985684?v=4" width="100px;"/><br /><sub><b>Arthur Puthin</b></sub>](https://github.com/aputhin)<br />[📖](https://github.com/kentcdodds/react-testing-library/commits?author=aputhin "Documentation") | [<img src="https://avatars2.githubusercontent.com/u/21194045?v=4" width="100px;"/><br /><sub><b>Thomas Chia</b></sub>](https://github.com/thchia)<br />[💻](https://github.com/kentcdodds/react-testing-library/commits?author=thchia "Code") [📖](https://github.com/kentcdodds/react-testing-library/commits?author=thchia "Documentation") | [<img src="https://avatars3.githubusercontent.com/u/20430611?v=4" width="100px;"/><br /><sub><b>Thiago Galvani</b></sub>](http://ilegra.com/)<br />[📖](https://github.com/kentcdodds/react-testing-library/commits?author=thiagopaiva99 "Documentation") |
-
+| [<img src="https://avatars1.githubusercontent.com/u/29602306?v=4" width="100px;"/><br /><sub><b>Michal Baranowski</b></sub>](https://twitter.com/baranovskim)<br />[📝](#blog-mbaranovski "Blogposts") [✅](#tutorial-mbaranovski "Tutorials") | [<img src="https://avatars3.githubusercontent.com/u/13985684?v=4" width="100px;"/><br /><sub><b>Arthur Puthin</b></sub>](https://github.com/aputhin)<br />[📖](https://github.com/kentcdodds/react-testing-library/commits?author=aputhin "Documentation") | [<img src="https://avatars2.githubusercontent.com/u/21194045?v=4" width="100px;"/><br /><sub><b>Thomas Chia</b></sub>](https://github.com/thchia)<br />[💻](https://github.com/kentcdodds/react-testing-library/commits?author=thchia "Code") [📖](https://github.com/kentcdodds/react-testing-library/commits?author=thchia "Documentation") | [<img src="https://avatars3.githubusercontent.com/u/20430611?v=4" width="100px;"/><br /><sub><b>Thiago Galvani</b></sub>](http://ilegra.com/)<br />[📖](https://github.com/kentcdodds/react-testing-library/commits?author=thiagopaiva99 "Documentation") | [<img src="https://avatars1.githubusercontent.com/u/19828824?v=4" width="100px;"/><br /><sub><b>Christian</b></sub>](http://Chriswcs.github.io)<br />[⚠️](https://github.com/kentcdodds/react-testing-library/commits?author=ChrisWcs "Tests") |
 <!-- ALL-CONTRIBUTORS-LIST:END -->
 
 This project follows the [all-contributors][all-contributors] specification.

src/__tests__/react-context.js

@@ -0,0 +1,47 @@
+import React from 'react'
+import {render, Simulate} from '../'
+
+const StateContext = React.createContext()
+
+const MyButton = () => (
+  <StateContext.Consumer>
+    {({handleToggle}) => <button onClick={handleToggle}>Push Me</button>}
+  </StateContext.Consumer>
+)
+
+const SecretMessage = () => (
+  <StateContext.Consumer>
+    {({toggleStatus}) => <h1>{toggleStatus ? 'Secret Message' : 'Hidden'}</h1>}
+  </StateContext.Consumer>
+)
+
+class Container extends React.Component {
+  handleToggle = () => {
+    this.setState(prevState => ({
+      toggleStatus: !prevState.toggleStatus,
+    }))
+  }
+
+  state = {
+    toggleStatus: false,
+    handleToggle: this.handleToggle,
+  }
+
+  render() {
+    return (
+      <div>
+        <StateContext.Provider value={this.state}>
+          <MyButton />
+          <SecretMessage />
+        </StateContext.Provider>
+      </div>
+    )
+  }
+}
+
+test('Component renders with the correct message then correctly changes message after clicking button', () => {
+  const {getByText} = render(<Container />)
+  expect(getByText('Hidden').textContent).toBe('Hidden')
+  Simulate.click(getByText('Push Me'))
+  expect(getByText('Secret Message').textContent).toBe('Secret Message')
+})