Add note about Node version support in README and docs. Fixes #4947 (#…

…5622)

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 * `[jest-runtime]` Provide `require.main` property set to module with test suite
   ([#5618](https://github.com/facebook/jest/pull/5618))
+* `[docs]` Add note about Node version support ([#5622](https://github.com/facebook/jest/pull/5622))
 
 ## 22.4.0
 

README.md

@@ -33,6 +33,11 @@ Or via [`yarn`](https://yarnpkg.com/en/package/jest):
 yarn add --dev jest
 ```
 
+The minimum supported Node version is `v6.0.0` by default. If you need to
+support Node 4, refer to the
+[Compatibility issues](https://facebook.github.io/jest/docs/en/troubleshooting.html#compatibility-issues)
+section.
+
 Let's get started by writing a test for a hypothetical function that adds two
 numbers. First, create a `sum.js` file:
 
@@ -96,23 +101,16 @@ page.
 
 ### Using Babel
 
-To use [Babel](http://babeljs.io/), install the `babel-jest` and
-`regenerator-runtime` packages:
+[Babel](http://babeljs.io/) is automatically handled by Jest using `babel-jest`.
+You don't need install anything extra for using Babel.
 
-```bash
-npm install --save-dev babel-jest babel-core regenerator-runtime
-```
-
-> Note: If you are using a babel version 7 then you need to install `babel-jest`
-> with the following command:
+> Note: If you are using a babel version 7 then you need to install
+> `babel-core@^7.0.0-0` and `@babel/core` with the following command:
 >
 > ```bash
-> npm install --save-dev babel-jest 'babel-core@^7.0.0-0' @babel/core regenerator-runtime
+> npm install --save-dev 'babel-core@^7.0.0-0' @babel/core
 > ```
 
-_Note: Explicitly installing `regenerator-runtime` is not needed if you use
-`npm` 3 or 4 or Yarn_
-
 Don't forget to add a [`.babelrc`](https://babeljs.io/docs/usage/babelrc/) file
 in your project's root folder. For example, if you are using ES6 and
 [React.js](https://facebook.github.io/react/) with the

docs/Troubleshooting.md

@@ -301,7 +301,12 @@ option to `jasmine1` or pass `--testRunner=jasmine1` as a command line option.
 
 Jest takes advantage of new features added to Node 6. We recommend that you
 upgrade to the latest stable release of Node. The minimum supported version is
-`v6.0.0`. Versions `0.x.x` and `4.x.x` are not supported.
+`v6.0.0`. Versions `0.x.x` and `4.x.x` are not supported because the `jsdom`
+version used in Jest doesn't support Node 4. However, if you need to run Jest on
+Node 4, you can use the `testEnvironment` config to use a
+[custom environment](https://facebook.github.io/jest/docs/en/configuration.html#testenvironment-string)
+that supports Node 4, such as
+[`jest-environment-node`](https://www.npmjs.com/package/jest-environment-node).
 
 ### `coveragePathIgnorePatterns` seems to not have any effect.