How to see coverage diff for a commit/PR?

[abitrolly]

Is there a way to see changes in coverage before sending PR? Specific lines that become covered, or lines with reduced coverage?

Or at the very least how to see which modified lines are missing the coverage?

That would be nice to see in docs/contributing.rst.

[Zlopez]

Yes, the diff-cover part of tox tests is doing exactly that.

[abitrolly]

How to see it? poetry run tox diff-cover obviously doesn't work.

[Zlopez]

You need to run poetry run tox -e diff-cover. It's a tox environment.

[abitrolly]

If the output of diff-cover is the same as Zuul produces, then it doesn't really show which lines are missing. So I added the instructions how to see the actual coverage, which is more useful for troubleshooting this error #1986