[Conversational snippet] Fix, refactor, & add tests #2390

	name: Lint
	on:
	pull_request:
	push:
	branches:
	- main

	jobs:
	lint:
	runs-on: ubuntu-latest
	timeout-minutes: 10

	steps:
	- uses: actions/checkout@v3
	with:
	# Could use something like rmacklin/fetch-through-merge-base@v0 instead when the repo gets bigger
	fetch-depth: 0
	- name: "Extracting the merge base into 'SINCE'"
	id: since
	run: \|
	if [ -z $PR_REF ]
	then
	echo "SINCE=$SHA^1" >> $GITHUB_OUTPUT
	else
	echo "SINCE=$(git merge-base origin/$PR_REF $SHA)" >> $GITHUB_OUTPUT
	fi
	env:
	PR_REF: ${{ github.event.pull_request.head.ref }}
	SHA: ${{ github.sha }}

	- run: corepack enable

	- uses: actions/setup-node@v3
	with:
	node-version: "20"
	cache: "pnpm"
	cache-dependency-path: "**/pnpm-lock.yaml"
	- run: \|
	pnpm install --frozen-lockfile --filter .
	pnpm install --frozen-lockfile --filter ...[${{ steps.since.outputs.SINCE }}]...
	pnpm --filter ...[${{ steps.since.outputs.SINCE }}]... build
	- name: "Checking lint errors"
	run: \|
	pnpm --filter ...[${{ steps.since.outputs.SINCE }}] lint:check

	- name: "Checking format errors"
	run: \|
	# Could also use pnpm --filter [${{ steps.since.outputs.SINCE }}] format:check
	# But this way we can see the diff
	pnpm --filter [${{ steps.since.outputs.SINCE }}] format
	git diff \| head -n 100
	git diff --name-only --exit-code

	- name: Check types
	run: pnpm --filter ...[${{ steps.since.outputs.SINCE }}] check

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