OperationDef as macros. #180

	name: Formatting

	# Run on every push to main and every change on pull requests
	on:
	push:
	branches: [ "main" ]
	pull_request:

	permissions:
	contents: read

	jobs:
	# Formatting checks
	format:
	name: "Checks"
	runs-on: ubuntu-latest

	# Checkout the code
	steps:
	- name: Checkout Scair
	uses: actions/checkout@v4

	# Restore Mill's incremental build cache
	- name: Cache Incremental Build
	uses: actions/cache@v4
	with:
	path: ./out
	# Caches are immutable; we need to uniquely identify them to always push the recent ones
	# There is an LRU-like policy in place on GitHub's side, capped at 10GB caches per repo
	key: mill-incremental-format-${{ github.run_id }}-${{ github.run_attempt }}
	# When restoring, we restore the most recent one pushed by such a job
	# Those are scoped by branch too; e.g., the most recent one from the main branch would
	# be fetched in a fresh PR, then the most recent one from this PR.
	restore-keys: \|
	mill-incremental-format-

	- name: Cache coursier packages
	uses: coursier/cache-action@v6
	- name: Install coursier packages (Scala and Mill)
	uses: coursier/setup-action@v1
	with:
	apps: scala:3.3.4

	# Check if the code is formatted as expected
	- name: Run format checks
	run: ./mill checkFormatAll

Provide feedback