[New] add `no-render-return-undefined`: disallow components rendering undefined #397

	name: 'Tests: node.js (18+)'

	on: [pull_request, push]

	jobs:
	matrix:
	runs-on: ubuntu-latest
	outputs:
	latest: ${{ steps.set-matrix.outputs.requireds }}
	minors: ${{ steps.set-matrix.outputs.optionals }}
	steps:
	- uses: ljharb/actions/node/matrix@main
	id: set-matrix
	with:
	versionsAsRoot: true
	type: majors
	preset: '>=18'

	latest:
	needs: [matrix]
	name: 'latest majors'
	runs-on: ubuntu-latest

	strategy:
	fail-fast: false
	matrix:
	node-version: ${{ fromJson(needs.matrix.outputs.latest) }}
	eslint:
	- 8
	- 7
	- 6
	- 5
	- 4
	- 4.14 # last version without messageId
	- 3
	babel-eslint:
	- 10
	- 9
	- 8

	steps:
	- uses: actions/checkout@v4
	- uses: ljharb/actions/node/install@main
	name: 'nvm install ${{ matrix.node-version }} && npm install'
	with:
	node-version: ${{ matrix.node-version }}
	after_install: \|
	npm install --no-save "eslint@${{ matrix.eslint }}" "@typescript-eslint/parser@5" "babel-eslint@${{ matrix.babel-eslint }}"
	env:
	NPM_CONFIG_LEGACY_PEER_DEPS: true
	- run: npx ls-engines
	- run: npm run unit-test
	- uses: codecov/[email protected]

	node:
	name: 'node 18+'
	needs: [latest]
	runs-on: ubuntu-latest
	steps:
	- run: 'echo tests completed'

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