Update coverage report to add inline PR comments.

[adiroiban]

Description

Fixes #450

Try to add inline comments for PR coverage

To make it easier to develop. I added some testing code for JS.
I guess that if all is ok, we can move it into a separate dedicated shared action.

In theory, we can convert this to Python code.

[codecov]

Codecov Report

Base: 100.00% // Head: 99.44% // Decreases project coverage by -0.55% ⚠️

Coverage data is based on head (e847dc8) compared to base (9554985).
Patch coverage: 0.00% of modified lines in pull request are covered.

Additional details and impacted files

@@             Coverage Diff             @@
##             trunk     #451      +/-   ##
===========================================
- Coverage   100.00%   99.44%   -0.56%     
===========================================
  Files           22       22              
  Lines         1607     1616       +9     
  Branches       286      288       +2     
===========================================
  Hits          1607     1607              
- Misses           0        7       +7     
- Partials         0        2       +2     

Impacted Files	Coverage Δ
src/towncrier/build.py	90.21% <0.00%> (-9.79%)	⬇️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.

[github-actions]

Name                     Stmts   Miss Branch BrPart  Cover   Missing
--------------------------------------------------------------------
src/towncrier/build.py      92      7     28      2    92%   123-126, 138-142
--------------------------------------------------------------------
TOTAL                     1616      7    234      2    99%

22 files skipped due to complete coverage.

Diff Coverage

Diff: origin/trunk...HEAD, staged and unstaged changes

• src/towncrier/build.py (22.2%): Missing lines 123,125-126,138,140-142

Summary

• Total: 9 lines
• Missing: 7 lines
• Coverage: 22%

src/towncrier/build.py

Lines 119-130

    click.echo("Finding news fragments...", err=to_err)

    if directory == "sdfafsdfasd":
        bla = "some line not covered"
        # a comment
        bla = "some line not covered"
        bla = "some line not covered"

    if config.directory is not None:
        fragment_base_directory = os.path.abspath(config.directory)
        fragment_directory = None

---

Lines 134-146

        )
        fragment_directory = "newsfragments"

    if directory == "sdfasdf":
        bla = "some line not covered"
        # a comment
        bla = "some line not covered"
        bla = "some line not covered"
        fragment_directory = bla

    fragment_contents, fragment_filenames = find_fragments(
        fragment_base_directory,
        config.sections,

---

[github-actions]

Missing coverage.

[github-actions]

Missing coverage.

[adiroiban]

I see that codecov.io is not using PR comments, but commit check warnings

I will continue working on this and try to use the checks API

[adiroiban]

I tried to see how to use the GitHub Check Annotations, but it is not clear how to add annotations

https://docs.github.com/en/rest/checks/runs#list-check-run-annotations

At the same time, I think that we should not rely too much on GitHub Api.

Instead, we should dedicated our time to improve the diff-cover project so that the markdown report is helpful.

I am going to close this PR.