refactor: update file_diff_contents to use git2 instead of CLI, make path helper more robust

[Scott McMaster (scottmcmaster)]

Summary

Port file_diff_contents over to git2 in the query submodule, also move associated tests. Create required new file operations in a new repo_files.rs file and add independent unit tests for them, Also make the path normalization helper more robust since the one that was there before looked like it might have a few robustness issues.

Test Plan

Added and updated unit tests, run evolve manually to trigger the diffing command.

• No test plan needed

Docs

• Docs updated (companion PR in darkmatter/nixmac-web: #___)
• No docs update needed

---

^{Need help on this PR? Tag /codesmith with what you need. Autofix is disabled.}

[Scott McMaster (scottmcmaster)]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• refactor: migrate commit_all and create_evolution_backup staging to git2, kill git_command wrapper #319
• refactor: migrate checkout_files_at_commit, restore_all, and restore_from_branch_ref to git2 #311
• refactor: migrate intent_add_untracked to git2, setting INTENT_TO_ADD flag without shelling out #310
• refactor: remove git stash command and related functionality #291
• refactor: migrate create_evolution_backup internals to git2, remove get_head_sha wrapper #290
• refactor: migrate tag_commit to git2, remove unused delete_backup_branch #289
• refactor: update file_diff_contents to use git2 instead of CLI, make path helper more robust #283 👈 (View in Graphite)
• refactor: port the git log function from CLI to git2 #281
• refactor: nix-files feedback reusing git status, eliminate resulting dead code #278
• fix: split made_edit_or_build_check into separate flags and minor whitespace cleanup #288
• develop

---

How to use the Graphite Merge Queue

Add either label to this PR to merge it via the merge queue:

• automerge - adds this PR to the back of the merge queue
• urgent - for urgent changes, fast-track this PR to the front of the merge queue

You must have a Graphite account in order to use the merge queue. Sign up using this link.

An organization admin has enabled the Graphite Merge Queue in this repository.

Please do not merge from GitHub as this will restart CI on PRs being processed by the merge queue.

This stack of pull requests is managed by Graphite. Learn more about stacking.

[github-actions]

📋 PR Overview

Lines changed	338 (+282 / -56)
Files	1 added, 4 modified, 0 deleted
Draft / WIP	no
Has Test Plan	yes
No Test Plan Needed	no
New UI components	no
New Storybook stories	no
New Rust modules	yes (1)
New TS source files	no
New tests	no
package.json touched	no
Cargo.toml touched	no
Infra / CI touched	no

🔬 Coverage

Report	Lines	Statements	Functions	Branches
apps/native/coverage/coverage-summary.json	26.3%	26.4%	24.2%	17.9%

Generated by 🚫 dangerJS against 452ba67

[Copilot]

Pull request overview

Refactors Git file-content diff retrieval to use git2 (instead of spawning the Git CLI), while hardening repository-relative path handling and centralizing repo file helpers in a dedicated module.

Changes:

• Moved file_diff_contents into the git::query (git2-based) layer and updated the Tauri command to call it.
• Added git::repo_files helpers for lexical path normalization plus reading HEAD/workdir contents, with new unit tests.
• Removed the old CLI-based file_diff_contents implementation and its associated tests from git::exec.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
apps/native/src-tauri/src/git/repo_files.rs	New helper module for safe-ish repo-relative path normalization and reading file contents from HEAD/workdir, plus unit tests.
apps/native/src-tauri/src/git/query.rs	Adds git2-backed file_diff_contents and ports tests to the query layer.
apps/native/src-tauri/src/git/mod.rs	Registers the new repo_files module.
apps/native/src-tauri/src/git/exec.rs	Removes the old CLI-based file_diff_contents implementation and tests.
apps/native/src-tauri/src/commands/git.rs	Updates the command to use git::query::file_diff_contents.

[Juanpe Bolívar (arximboldi)]

Neat!

[cooper (czxtm)]

nice, leaving this as a note-to-self, as this just got me thinking about symlinks that DO cross the repository boundary, since it is pretty common to symlink files to e.g. ~/.config/code/settings.json to sync vs code settings across machines.

[graphite-app]

Merge activity

• Jun 5, 12:29 AM UTC: czxtm added this pull request to the Graphite merge queue.
• Jun 5, 12:30 AM UTC: CI is running for this pull request on a draft pull request (#318) due to your merge queue CI optimization settings.
• Jun 5, 12:33 AM UTC: The Graphite merge queue removed this pull request due to downstack failures on PR #281.
• Jun 5, 12:33 AM UTC: The Graphite merge queue removed this pull request due to downstack failures on PR #281.
• Jun 5, 1:30 AM UTC: czxtm added this pull request to the Graphite merge queue.
• Jun 5, 1:31 AM UTC: CI is running for this pull request on a draft pull request (#321) due to your merge queue CI optimization settings.
• Jun 5, 1:37 AM UTC: Merged by the Graphite merge queue via draft PR: #321.