fix: use only version tags in changelog

[sacha-c]

All tags used to generate the changelog must be version tags.
This PR fixes two issues:

• The 'latest' commit was not being checked for it being a version tag, which can result in some non-version tag written as a header for the changelog
• The rev-range created when running cz changelog 3.2.0 could use a non-version tag as a lower-bound, resulting in an incomplete changelog if the non-version tag was in the middle of two versions.

Description

Changelogs should be generated only with version tags as headers. Tags are indeed being checked that they are version tags when generating the changelog here, but this logic is missing for the latest commit's tag.

This means that changelogs can be generated with an incorrect tag for the latest version

For example, if I have a project with a commit "feat: some change" tagged with a tag "i_am_not_a_version", running cz changelog will generate something like:
See that the output is

## i_am_not_a_version (2023-05-10)

### Feat

- some change

instead of

## Unreleased
...

or

## 0.1.0 (2023-05-10)
...

Checklist

• Add test cases to all the changes you introduce
• Run ./scripts/format and ./scripts/test locally to ensure this change passes linter check and test
• Test the changes on the local machine manually
• Update the documentation for the changes (not relevant)

Expected behavior

The changelog should only contain version tags

Steps to Test This Pull Request

On a project with commitizen setup

1. touch some-change
2. git commit -m "feat: some change"
3. git tag a-tag-that-has-nothing-to-do-with-versions
4. cz changelog --dry-run

closes #741

[codecov]

Codecov Report

Patch coverage: 98.59% and project coverage change: +0.10 🎉

Comparison is base (eb39f8b) 97.31% compared to head (b28670a) 97.41%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #740      +/-   ##
==========================================
+ Coverage   97.31%   97.41%   +0.10%     
==========================================
  Files          42       42              
  Lines        2045     2086      +41     
==========================================
+ Hits         1990     2032      +42     
+ Misses         55       54       -1     

Flag	Coverage Δ
unittests	97.41% <98.59%> (+0.10%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...en/cz/conventional_commits/conventional_commits.py	100.00% <ø> (ø)
commitizen/providers.py	97.47% <88.88%> (+0.18%)	⬆️
commitizen/commands/bump.py	97.63% <96.55%> (-0.52%)	⬇️
commitizen/version_schemes.py	98.42% <98.42%> (ø)
commitizen/__version__.py	100.00% <100.00%> (ø)
commitizen/bump.py	100.00% <100.00%> (ø)
commitizen/changelog.py	99.49% <100.00%> (-0.51%)	⬇️
commitizen/changelog_parser.py	96.96% <100.00%> (+0.04%)	⬆️
commitizen/cli.py	94.20% <100.00%> (ø)
commitizen/commands/changelog.py	98.92% <100.00%> (-0.03%)	⬇️
... and 14 more

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

[sacha-c]

My PR is not passing coverage/patch because my changes include code that is run conditionally based on the OS (if os.name == 'nt)

My code is actually covered through tests, but it doesn't end up in coverage.xml because codecov only uses coverage.xml generated from linux runs:

commitizen/.github/workflows/pythonpackage.yml

Lines 31 to 32 in 5cd12cb

	- name: Upload coverage to Codecov
	if: runner.os == 'Linux'

Any suggestion on how to proceed?

EDIT: added pragma: no cov

[Lee-W]

Hi @sacha-c sorry for the late reply. Both maintainers are a bit overwhelmed these days. I've verified this issue and am now going to take a deeper look at this PR. Thanks for your contribution!

[Lee-W]

Hi @sacha-c , I tried to resolve the conflict due to the latest merged PRs, but it seems to fail on the windows instance. Could you please take a look at the windows issue? I think we're almost ready to merge this one 💪

[sacha-c]

Hi @sacha-c , I tried to resolve the conflict due to the latest merged PRs, but it seems to fail on the windows instance. Could you please take a look at the windows issue? I think we're almost ready to merge this one 💪

Thanks for checking this issue! 🙂

I had a look at the error and at first glance it seems unrelated to the changes of this PR. The test failing is test_bump_pre_commit_changelog, and the exception is thrown when installing pre-commit
* Install prebuilt node (20.3.1) .Failed to download from https://nodejs.org/download/release/v20.3.1/node-v20.3.1-win-x64.zip
Is there a way to re-run the test suite and see if that fixes it?

[Lee-W]

Yep, you're right. After I reran it, it succeeded. 🙂

[Lee-W]

This fix looks good to me.

@woile I'm planning to merge it this weekend. Let me know if you want to take a deeper look 🙂