Improved description and added a React-Intl setup description on setup.

Author: viniciusavieira

docs/example-react-intl.md

@@ -3,6 +3,11 @@ id: example-react-intl
 title: React Intl
 ---
 
+> **Note**
+>
+> If you want to combine setupTests with another setup you should check
+> [`setup`](react-testing-library/setup.md)
+
 ```jsx
 import React from 'react'
 import 'jest-dom/extend-expect'
@@ -36,9 +41,7 @@ const FormatDateView = () => {
 }
 
 const renderWithReactIntl = component => {
-  return {
-    ...render(<IntlProvider locale="pt">{component}</IntlProvider>),
-  }
+  return render(<IntlProvider locale="pt">{component}</IntlProvider>)
 }
 
 setupTests()

docs/react-testing-library/setup.md

@@ -226,3 +226,29 @@ mocha --require jsdom-global/register
 Note, depending on the version of Node you're running, you may also need to
 install @babel/polyfill (if you're using babel 7) or babel-polyfill (for babel
 6).
+
+## Configuring React-Intl Polyfills
+
+If you're using React-Intl in your project, and you need to load a locale, you
+must load the Polyfills according to that language.
+
+In order to do so, you may use this small setup and/or combine it with other
+setups.
+
+```
+// src/setupTests.js
+import IntlPolyfill from 'intl'
+import 'intl/locale-data/jsonp/pt'
+
+const setupTests = () => {
+ // https://formatjs.io/guides/runtime-environments/#server
+ if (global.Intl) {
+   Intl.NumberFormat = IntlPolyfill.NumberFormat
+   Intl.DateTimeFormat = IntlPolyfill.DateTimeFormat
+ } else {
+   global.Intl = IntlPolyfill
+ }
+}
+
+setupTests();
+```