refactor(git): code cleanup and test coverage

[bearomorphism]

Description

• Removed EOLTypes. I think it's unnecessary.
• It's probably not a good practice to name a variable map.
• Improve clarity of type hints.
• Extract some subroutines to improve readability.

Checklist

• I have read the contributing guidelines

Code Changes

• Add test cases to all the changes you introduce
• Run poetry all locally to ensure this change passes linter check and tests
• Manually test the changes:
  • Verify the feature/bug fix works as expected in real-world scenarios
  • Test edge cases and error conditions
  • Ensure backward compatibility is maintained
  • Document any manual testing steps performed
• Update the documentation for the changes

Documentation Changes

• Run poetry doc locally to ensure the documentation pages renders correctly

Expected Behavior

Steps to Test This Pull Request

Additional Context

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.59%. Comparing base (120d514) to head (40abbbd).
Report is 610 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1417      +/-   ##
==========================================
+ Coverage   97.33%   97.59%   +0.25%     
==========================================
  Files          42       57      +15     
  Lines        2104     2659     +555     
==========================================
+ Hits         2048     2595     +547     
- Misses         56       64       +8     

Flag	Coverage Δ
unittests	97.59% <100.00%> (+0.25%)	⬆️

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[noirbizarre]

Good cleanup, thanks!
For the f-string remark, I'll let @Lee-W decide

[bearomorphism]

It seems that some lines are not covered before this PR change. I'll try to cover them.

[bearomorphism]

Just vibe tested the changes.

[bearomorphism]

Finally passed codecov/patch check...

[bearomorphism]

I just split the changes into multiple PRs so it's easier to review.