feat: configurable commit validation

[protonjohn]

Allow clients overriding the BaseCommitizen object to have more custom commit message validation beyond just matching a regex schema. This lets clients have custom error messages and more intelligent pattern matching.

Description

This change lets users add certain things like bad word filters or more intelligent task ID listing (for example, make sure one or more IDs appears in the commit message, and in no particular order).

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

Expected behavior

Override validate_commit or validate_commits in BaseCommitizen for commit validation functions that are expressible in Python, and not just by a regular expression.

Steps to Test This Pull Request

Run the test_check_custom_validation_succeeds and test_check_custom_validation_fails test cases in tests/commands/test_check_command.py.

Additional context

I noticed during my development that the test_check_command_with_empty_range case was failing with the error:

commitizen.exceptions.GitCommandError: fatal: ambiguous argument 'master..master': unknown revision or path not in the working tree.

instead of generating its expected output. I did my best to make sure that this failure wasn't related to my changes, since it also reproduced when I ran the test suite against master. It could just be an issue with my local environment.

[codecov]

Codecov Report

Base: 97.92% // Head: 98.01% // Increases project coverage by +0.08% 🎉

Coverage data is based on head (006026a) compared to base (db42a95).
Patch coverage: 91.89% of modified lines in pull request are covered.

❗ Current head 006026a differs from pull request most recent head bbe424a. Consider uploading reports for the commit bbe424a to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #648      +/-   ##
==========================================
+ Coverage   97.92%   98.01%   +0.08%     
==========================================
  Files          35       39       +4     
  Lines        1252     1710     +458     
==========================================
+ Hits         1226     1676     +450     
- Misses         26       34       +8     

Flag	Coverage Δ
unittests	98.01% <91.89%> (+0.08%)	⬆️

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

Impacted Files	Coverage Δ
commitizen/commands/init.py	87.93% <84.00%> (-3.74%)	⬇️
commitizen/cz/customize/customize.py	95.34% <96.29%> (+0.26%)	⬆️
commitizen/__version__.py	100.00% <100.00%> (ø)
commitizen/commands/changelog.py	98.86% <100.00%> (ø)
commitizen/commands/check.py	100.00% <100.00%> (ø)
commitizen/cz/__init__.py	100.00% <100.00%> (ø)
commitizen/cz/base.py	100.00% <100.00%> (ø)
commitizen/cz/customize/__init__.py	100.00% <100.00%> (ø)
commitizen/exceptions.py	100.00% <100.00%> (ø)
commitizen/changelog.py	99.43% <0.00%> (ø)
... and 3 more

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[protonjohn]

I'm not sure why the patch check is failing - it's complaining about a lack of test code coverage in a file that I didn't touch.

[Lee-W]

I'm not sure why we need to add this Cz rule. Could you describe a bit more? Thanks!

[protonjohn]

It's mostly so that I could test it in the unit tests, but also to give others an example to work with if they want to use the feature. I didn't see a better place to put it, if you can suggest one I'm happy to put it somewhere :)

[Lee-W]

I'm thinking of moving it to tests. Not sure whether it works

[Lee-W]

It seems the latest version didn't pass the CI. @protonjohn could you please take a look? Thanks!