v20.7.1 proposal #23732

	name: First commit message adheres to guidelines

	on: [pull_request]

	env:
	NODE_VERSION: lts/*

	permissions:
	contents: read

	jobs:
	lint-commit-message:
	runs-on: ubuntu-latest
	steps:
	- name: Compute number of commits in the PR
	id: nb-of-commits
	run: \|
	echo "plusOne=$((${{ github.event.pull_request.commits }} + 1))" >> $GITHUB_OUTPUT
	echo "minusOne=$((${{ github.event.pull_request.commits }} - 1))" >> $GITHUB_OUTPUT
	- uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
	with:
	fetch-depth: ${{ steps.nb-of-commits.outputs.plusOne }}
	persist-credentials: false
	- run: git reset HEAD^2
	- name: Install Node.js
	uses: actions/setup-node@5e21ff4d9bc1a8cf6de233a3057d20ec6b3fb69d # v3.8.1
	with:
	node-version: ${{ env.NODE_VERSION }}
	- name: Validate commit message
	run: \|
	echo "::add-matcher::.github/workflows/commit-lint-problem-matcher.json"
	git rev-parse HEAD~${{ steps.nb-of-commits.outputs.minusOne }} \| xargs npx -q core-validate-commit --no-validate-metadata --tap

Provide feedback