fix: harden post-commit hook against non-UTF8 encoding

[mikemolinet]

Summary

• Harden four .decode() calls in hooks/post-commit.py against non-UTF8 git output by passing errors="replace"
• Matches existing pattern in src/brainlayer/pipeline/extract_markdown.py:50
• Adds tests/test_post_commit_hook.py covering the non-UTF8 commit-message and file-path paths plus a valid-UTF-8 sanity test

Root cause

The outer try/except (CalledProcessError, FileNotFoundError) at line 30 doesn't catch UnicodeDecodeError. On a commit whose message or file paths contain non-UTF8 bytes (e.g., i18n.commitEncoding=latin-1, legacy SVN-imported metadata, or non-UTF8 filesystem paths), the hook crashes with a traceback and store_memory() never runs — silently dropping that commit from BrainLayer indexing.

Test plan

• pytest tests/test_post_commit_hook.py -v
• pytest tests/ -m "not integration"
• ruff check src/ tests/
• ruff format --check src/ tests/

Summary by CodeRabbit

Release Notes

• Bug Fixes

  • Enhanced robustness when processing git commits and file paths containing non-UTF-8 characters, ensuring graceful error handling and recovery.

• Tests

  • Added comprehensive test coverage for character encoding scenarios, validating proper handling of non-UTF-8 inputs, Latin-1 encoded text, and multi-byte UTF-8 characters.

Note

Harden post-commit hook against non-UTF-8 git output

Replaces plain .decode() calls in post-commit.py with .decode('utf-8', errors='replace') for all git subprocess outputs (commit hash, message, file paths, repo toplevel). This prevents UnicodeDecodeError when git returns non-UTF-8 bytes, substituting U+FFFD for undecodable bytes instead. Adds a test module covering non-UTF-8 commit messages, file paths, and repo paths, as well as a regression test confirming valid UTF-8 (including non-ASCII) passes through unchanged.

^{Macroscope summarized b9fcc42.}

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[coderabbitai]

📝 Walkthrough

Walkthrough

The PR updates the post-commit hook to explicitly decode subprocess git command outputs as UTF-8 with error replacement, and adds comprehensive test coverage validating correct behavior with both valid and invalid UTF-8 sequences in commit messages and file paths.

Changes

Cohort / File(s)	Summary
Post-commit Hook UTF-8 Decoding hooks/post-commit.py	Updated git-output decoding for commit_hash, commit_msg, files_changed, and repo_root to explicitly use UTF-8 with errors="replace", replacing prior default .decode() behavior while preserving control flow and error handling.
Test Coverage for Hook tests/test_post_commit_hook.py	Added pytest test suite with three tests: validation of non-UTF-8 commit messages, non-UTF-8 file paths, and UTF-8 sanity checks. Tests dynamically load hook module, mock subprocess git commands, stub brainlayer modules, and assert correct decoding behavior including replacement character insertion on invalid sequences.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Poem

🐰 A UTF-8 fix hops into place,
No garbled text to slow the race!
With errors="replace" standing strong,
Invalid bytes won't go wrong,
Tests ensure our commits decode with grace! ✨

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 25.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'fix: harden post-commit hook against non-UTF8 encoding' directly and accurately describes the main change: hardening the post-commit hook by adding UTF-8 error handling.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@tests/test_post_commit_hook.py`:
- Around line 70-87: Add a regression test that covers non-UTF8 bytes returned
by git --show-toplevel: extend the existing helper _make_fake_check_output (and
its test usages around tests/test_post_commit_hook.py lines ~107-141) to return
a toplevel_bytes value containing a non-UTF8 byte sequence (e.g. include \xFF)
and add a new test case that uses that helper to assert the hook still correctly
handles/decodes the repo root; locate the factory function
_make_fake_check_output and the inner fake(cmd, **kwargs) and add the
failing-case scenario for "--show-toplevel" to ensure the code path for repo
root decoding is exercised.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro

Run ID: e30cefb7-e3e8-4613-8324-c2d2a848ec23

📥 Commits

Reviewing files that changed from the base of the PR and between 15ab4e9 and 92f1401.

📒 Files selected for processing (2)

• hooks/post-commit.py
• tests/test_post_commit_hook.py

📜 Review details

🧰 Additional context used

📓 Path-based instructions (1)

**/*.py

📄 CodeRabbit inference engine (AGENTS.md)

**/*.py: Flag risky DB or concurrency changes explicitly and do not hand-wave lock behavior
Enforce one-write-at-a-time concurrency constraint; reads are safe but brain_digest is write-heavy and must not run in parallel with other MCP work
Run pytest before claiming behavior changed safely; current test suite has 929 tests

**/*.py: Use paths.py:get_db_path() for all database path resolution; all scripts and CLI must use this function rather than hardcoding paths
When performing bulk database operations: stop enrichment workers first, checkpoint WAL before and after, drop FTS triggers before bulk deletes, batch deletes in 5-10K chunks, and checkpoint every 3 batches

Files:

• hooks/post-commit.py
• tests/test_post_commit_hook.py

🧠 Learnings (1)

📚 Learning: 2026-03-14T02:20:54.656Z

Learnt from: CR
Repo: EtanHey/brainlayer PR: 0
File: AGENTS.md:0-0
Timestamp: 2026-03-14T02:20:54.656Z
Learning: Applies to **/*.py : Run pytest before claiming behavior changed safely; current test suite has 929 tests

Applied to files:

• tests/test_post_commit_hook.py

🔇 Additional comments (3)

hooks/post-commit.py (1)

17-25: Decode hardening is correctly and consistently applied.

All modified git-output decode paths now use explicit UTF-8 with replacement, which prevents hook aborts on invalid byte sequences while preserving forward progress.

Also applies to: 32-45

tests/test_post_commit_hook.py (2)

89-141: Great targeted regression tests for non-UTF8 commit metadata.

These tests accurately capture the original failure mode and validate safe behavior after the decode change.

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1-141: [Your rewritten review comment text here]
[Exactly ONE classification tag]