feat(config): add find_root_meta_dir() for ancestor discovery

[mateodelnorte]

Summary

• Adds find_root_meta_dir() that walks up through parent .meta configs to find the topmost meta directory in the hierarchy
• Used by meta project list --recursive (in meta_project_cli) to start from the root ancestor instead of the nearest meta-repo
• 3 unit tests covering single-level, two-level, and three-level hierarchies

Test plan

• cargo test -p meta_core -- find_root_meta_dir — 3/3 passing
• cargo test --workspace — 652 tests, 0 failures

🤖 Generated with Claude Code

Summary by CodeRabbit

• New Features

  • Enhanced meta directory handling with support for hierarchical configuration structures, enabling the system to correctly identify and navigate nested .meta configurations from child to root level.

• Tests

  • Added comprehensive unit tests validating single, two, and three-level directory hierarchy scenarios.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

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Walkthrough

A new public utility function find_root_meta_dir is added to src/config.rs that traverses upward from a given .meta directory to locate the topmost parent .meta configuration by repeatedly invoking find_parent_meta_config. Comprehensive unit tests verify correct behavior across single, two-level, and three-level hierarchies.

Changes

Cohort / File(s)	Summary
Root Meta Directory Traversal src/config.rs	Added public function find_root_meta_dir that iteratively finds the topmost parent .meta configuration directory. Includes unit tests for single-level, two-level, and three-level hierarchies, plus root detection verification. Existing logic remains unchanged.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• refactor: move config module from meta_cli to meta_core #3: Implements the find_parent_meta_config function that find_root_meta_dir depends upon for traversing upward through the .meta directory hierarchy.

Poem

🐰 Hop hop, up we go,
Through parent configs, row by row,
Until the root declares its claim,
Where hierarchy finds its name. ✨

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'feat(config): add find_root_meta_dir() for ancestor discovery' accurately and clearly summarizes the main change: adding a new function for discovering ancestor meta directories.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

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✨ Finishing Touches

• 📝 Generate docstrings (stacked PR)
• 📝 Generate docstrings (commit on current branch)

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch feat/project-list-root-walk

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[greptile-apps]

Greptile Summary

Adds find_root_meta_dir() to walk up the directory hierarchy and find the topmost meta-repo ancestor. This enables meta project list --recursive to start from the root instead of the nearest meta-repo.

Changes:

• New public function find_root_meta_dir() that repeatedly calls find_parent_meta_config() until no more parents are found
• Comprehensive test coverage with 3 unit tests (no parent, two-level, three-level hierarchies)
• All 652 workspace tests pass according to PR description

Notes:

• The function uses a defensive .unwrap_or(Path::new(".")) fallback that may be unnecessary but doesn't cause issues
• Implementation correctly handles the case where meta_dir is already the root (returns unchanged)

Confidence Score: 4/5

• Safe to merge with minimal risk
• Well-tested new function with clear use case. Implementation is straightforward and builds on existing helper functions. Minor style consideration around error handling doesn't affect correctness.
• No files require special attention

Important Files Changed

Filename	Overview
src/config.rs	Added find_root_meta_dir() function with comprehensive test coverage (3 tests); implementation looks solid with minor consideration for edge case handling

_{Last reviewed commit: f12f19b}

[greptile-apps]

_{1 file reviewed, 1 comment}

_{Edit Code Review Agent Settings | Greptile}

[mateodelnorte]

Addressed review feedback: replaced .unwrap_or(Path::new(".")) with .expect("config file path should always have a parent directory") — since parent() on a file path returned by find_parent_meta_config should always succeed. Fixed in 9af9d83.