Conditional logic for deployment commit messages isn't working

[ollietreend]

When GitHub Actions deploys to GitHub Pages, it uses conditional logic to decide which commit message to use. According to the config file, it looks like the commit message should be determined by the event that triggered the build:

govuk-developer-docs/.github/workflows/ci.yml

Lines 31 to 38 in b0c0a6d

	- name: Set commit message up front
	id: commit_message_writer
	run: | # `github.event.number` will be blank if this is a cron
	if [ "${{ github.event.number }}" == "" ]; then
	echo "::set-output name=commit_message::Hourly scheduled redeploy"
	else
	echo "::set-output name=commit_message::Deploy via merge"
	fi

However in practice, the commit message is always "Hourly scheduled redeploy".

It looks like ${{ github.event.number }} always evaluates to an empty string. This seems consistent with the GitHub docs for builds triggered by a 'push' event, which suggests that number isn't a property of 'push' events.

Instead, I think we could probably change the if statement to something like this:

- if [ "${{ github.event.number }}" == "" ]; then
+ if [ "${{ github.event_name }}" == "schedule" ]; then

It assumes that cron-triggered builds have an event_name of "schedule" – which I think is correct, but this assumption would need to be tested.