mycase / landa Goto Github PK

https://github.com/appfolio/landa/blob/a27faf2c30384ed8c9d249197f75eb499a0a006a/lambda_function.py#L130

Landa adds commit statues to the last commit returned by the PR's list of commits, which are ordered by authorship time. This is not a reliable way to get the head commit because ordering commits by authorship time does form a topological ordering. Landa should instead just use the PR's head commit to add statuses.

Here's an example of it doing the wrong thing: https://github.com/appfolio/mycase_app/pull/2950

Currently, the github status(es) are created (as pending) whenever a PR is opened or a new commit is made to a PR. This works well in situations when CI is configured to run on PRs (refs/pulls/*/head). However, in cases where CI is configured to run on commits (refs/head/*), opening a PR can cause landa to override previously reported status with pending ones.

We could improve landa to first check whether a status for a sha already exists before creating one.

@balloob thoughts?