Can I use codecov.yml to ensure that files touched by a PR increase coverage of those files above a certain threshold or delta?

I have a repo whose overall coverage level is 50%. My goal is 90%, but I know that a single PR won’t get me there. What I’d like to do is a setting that says:

Pass the PR only if the files impacted by the PR are all at 90% coverage or greater, and the PR does not decrease overall coverage.

Is this possible?

I think the codecov/patch status might be able to do what you need. You can review the difference between codecov patch and project statuses here: https://docs.codecov.io/docs/commit-status

I think you would want to supply the thresholds in your codecov.yml like so:

coverage:
  status:
    patch:
      default:
        target: 90%