[GENERAL] Add .nvmrc + fix node version for eslint 5 compat

[slorber]

A .nvmrc file is practical when working on many node projects with different version requirements.

Also, the current required node engine is incompatible with eslint5 requirements:

  "engines": {
    "node": ">=8"
  },

It produces the following warning on install:

error eslint@5.0.1: The engine "node" is incompatible with this module. Expected version "^6.14.0 || ^8.10.0 || >=9.10.0".
error Found incompatible module

I made the requirement compatible with eslint5 requirements

Test Plan:

yarn test is still passing

Release Notes:

[GENERAL] [ENHANCEMENT] Add .nvmrc and ensure node version required is compatible with ESLint 5

[pull-bot]

	Warnings
⚠️	📋 Release Notes - This PR may have incorrectly formatted Release Notes.

Generated by 🚫 dangerJS

[slorber]

not sure exactly why ios e2e tests are failing on CI, any idea?

[janicduplessis]

Tests are currently broken on master, sorry about that.

I think if we change this we'd have to bump the minimum node version from 8 to 8.10. There might be some docs to update as well as https://github.com/facebook/react-native/blob/master/local-cli/server/checkNodeVersion.js#L17.

We actually require 8.3 anyway because of some use of object destructuring.

[slorber]

Ok thanks, I'll update my PR with doc + checkNodeVersion to 8.10 soon

[slorber]

@janicduplessis actually not sure if I should make the changes you wanted

ReactNative can actually work for node >= 8.3, it's just ESLint which requires 8.10. So it may be a good idea to have a .nvmrc 8.10 for contributors, but not necessary to force end users to use 8.10 as they won't run ESLint anyway. I don't think the engines attribute allow that granularity between distinct version requirement for devtools and consumer code.

Maybe it's better to let engine >= 8.3 and only add nvmrc for a recommended contributor version to use?

cc @hramos who changed the version recently: https://github.com/facebook/react-native/pull/20236/files

[hramos]

@slorber that approach sounds good - let's use engine for end-user minimum required Node version, .nvmrc for contributors.

[slorber]

ok,

I've reverted the PR's code to only add a .nvmrc and let the engine >= 8.3

[facebook-github-bot]

hramos is landing this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[react-native-bot]

This pull request was closed by @slorber in 30b9d81.

Once this commit is added to a release, you will see the corresponding version tag below the description at 30b9d81. If the commit has a single master tag, it is not yet part of a release.