feat: Add stats command to allow user to compare aider usage across different revision

[josix]

TODO:

• Implementation
• E2E Test
• Unit Test

This pull request introduces a new feature to show code change statistics between revisions and refactors existing code to support this functionality. The most important changes include adding a new command, updating argument parsing, and refactoring common functions into a new module.

New Feature: Code Change Statistics

• Added --stats argument to show code change statistics between revisions in aider/args.py.
• Implemented cmd_stats method to calculate and display code change statistics in aider/commands.py.
• Added logic to handle --stats argument in aider/main.py.

Refactoring for Code Reuse

• Moved functions hash_len, get_all_commit_hashes_between_tags, get_commit_authors, and get_counts_for_file to a new module aider/stats.py for reuse.

Codebase Simplification

• Updated imports in aider/commands.py and scripts/blame.py to use refactored functions from aider/stats.py. [1] [2]
• Removed redundant functions from scripts/blame.py after refactoring. [1] [2]

Example

aider --env-file ~/aider/.env --stats v0.69.0..v0.71.0
Aider v0.71.2.dev21+g620ae5cf.d20250116
Main model: claude-3-5-sonnet-20241022 with diff edit format, infinite output
Weak model: claude-3-5-haiku-20241022
Git repo: .git with 426 files
Repo-map: using 4096 tokens, auto refresh
Found 109 non-binary tracked files in the repository.

Analysis from v0.69.0 to v0.71.0:
Total lines analyzed: 6,440
Lines by aider: 1,147 (17.8%)
Lines by humans: 5,293 (82.2%)

[CLAassistant]

All committers have signed the CLA.

[MrOrz]

Related discussion on Discord: https://discord.com/channels/1131200896827654144/1263352706836332554/1263580285933715488

[MrOrz]

I gave this branch a few shots and it is working as expected, calculating the Aider % between two commits. 👍🏻 👍🏻 👍🏻

It would be nice if running aider --stats without specifying any commits would compare HEAD against the master or main branch.

[josix]

Thanks @MrOrz for pointing it out, I've added the compared revision (HEAD) as the default value and unit tests as well.

[MrOrz]

Not sure if aider --stats will be merged anytime soon.
Alternatively, I have created a bash script that calculate AI percentage here: https://github.com/MrOrz/mcp-git-commit-aider?tab=readme-ov-file#calculating-ai-contribution