Make deployment link on pull request if CI is running on pull request

[nojvek]

This action has a bug where the deployment link doesn't show on pull request.

Expected: A deployment link is shown in PR timeline:

[nojvek]

fyi @nwtgck ^

[nwtgck]

@nojvek

Thanks! But, this action already shows a deployment link as follows on a PR.

(17 days ago)

actual: nwtgck/piping-ui-web#842

[nwtgck]

But, anyway I tested this PR on #522

[nojvek]

If you notice there is a difference between “GitHub bot deployed to commit” and “GitHub bot deployed pull request” The issue we were running is when the base branch is ahead of PR base then GitHub generates a sha (that is new but not committed anywhere) which is different from head sha. So I do see the deployment in deployment list but it doesn’t show up in PR.

[nwtgck]

@nojvek Thank you so much for the detail. I'll reproduce and check the issue. Do you have a reproduced PR? If it is an open PR, I'd like to see it.

[nojvek]

It’s in a private repo. I’ll have to see whether I can make an open repo with a repro.

As additional context it has GitHub setting “enforce linear history” turned on.

[nojvek]

@nwtgck see more context on this https://github.community/t/github-sha-isnt-the-value-expected/17903

I borrowed this functionality from other netlify action that did post deploy links reliably https://github.com/South-Paw/action-netlify-deploy/blob/master/src/main.ts#L13-L21

However that action doesn't output the url that was deployed, but this action does that so trying to make it better.

[nwtgck]

@nojvek Thank you so much for the detailed explanation!