Cleanup cache #79

	# GH will purge cache items when full to make room but keep things tidy
	# when cached assets are (likely) no longer required
	name: Cleanup cache

	on:
	workflow_dispatch:
	schedule:
	- cron: "0 11 * * *"
	pull_request:
	types:
	- closed

	jobs:
	cleanup:
	runs-on: ubuntu-latest
	permissions:
	actions: write
	steps:
	- name: Check out code
	uses: actions/checkout@v4

	- name: Cleanup caches older than 5 days
	if: github.event_name == 'schedule' \|\| github.event_name == 'workflow_dispatch'
	uses: MyAlbum/purge-cache@v2
	with:
	max-age: 432000

	# https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows#force-deleting-cache-entries
	- name: Cleanup on PR close
	if: github.event_name == 'pull_request'
	env:
	GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
	GH_REPO: ${{ github.repository }}
	BRANCH: refs/pull/${{ github.event.pull_request.number }}/merge
	run: \|
	echo "Fetching list of cache key"
	cacheKeysForPR=$(gh cache list --ref $BRANCH --limit 100 --json id --jq '.[].id')

	## Setting this to not fail the workflow while deleting cache keys.
	set +e
	echo "Deleting caches..."
	for cacheKey in $cacheKeysForPR
	do
	gh cache delete $cacheKey
	done
	echo "Done"

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