refactor: extract shared VCS infrastructure

[benvinegar]

Summary

• add the private @hunk/vcs workspace under packages/hunk-vcs
• extract provider-neutral process, diff-target, path, source, and large-file infrastructure
• preserve the canonical import-free hunkdiff/extension contract
• migrate bundled providers to explicit shared helper subpaths and enforce package boundaries

Validation

• typecheck, lint, Knip, dependency boundaries
• full unit suite and focused provider tests
• npm build, pack validation, NodeNext and Bundler consumers

This is PR 1 of 4 in Phase 2. It intentionally does not extract a provider or change activation behavior.

This PR description was generated by Pi using GPT-5.6 Sol

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1 Skipped Deployment

Project	Deployment	Actions	Updated
hunk-web	Ignored		Sep 6, 2026 5:08am UTC

[greptile-apps]

Greptile Summary

This PR extracts provider-neutral VCS infrastructure into a new private @hunk/vcs workspace and rewires Git, Jujutsu, Sapling, and compatibility modules to consume explicit package subpaths.

• Adds package, source-boundary, dependency-cruiser, Knip, TypeScript, Bun lock, and Nix lock configuration.
• Moves subprocess, path, source-text, and diff-target helpers into the new dependency-bottom package.
• Preserves selected legacy Hunk imports through compatibility re-exports.
• Adds package-boundary and isolated type-resolution coverage.

Confidence Score: 4/5

The PR appears safe to merge after correcting the non-blocking Node compatibility claim in the private VCS package.

The extraction and provider rewiring are internally consistent, but the new package advertises Node support despite exporting Bun-dependent runtime implementations and only testing type resolution.

Files Needing Attention: packages/hunk-vcs/package.json, packages/hunk-vcs/src/async-process.ts, packages/hunk-vcs/src/source.ts

Important Files Changed

Filename	Overview
packages/hunk-vcs/package.json	Defines the private helper package and explicit source exports, but overstates Node runtime compatibility.
packages/hunk-vcs/src/source.ts	Relocates bounded file and stream readers plus subprocess cleanup into the new package.
packages/hunk-vcs/src/async-process.ts	Moves the existing abortable Bun subprocess implementation without behavioral changes.
packages/hunk/src/extensions/default/vcs/git/commands.ts	Rewires Git command helpers to consume explicit @hunk/vcs subpaths.
scripts/hunk-vcs-package.test.ts	Checks package boundaries and TypeScript resolution, but does not validate the declared Node runtime.
scripts/source-boundaries.test.ts	Extends architectural checks to keep the new package dependency-bottom and provider imports constrained.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    ExtensionAPI["hunkdiff/extension contract"]
    VCS["@hunk/vcs helper leaves"]
    Git["Bundled Git provider"]
    JJ["Bundled Jujutsu provider"]
    Sapling["Bundled Sapling provider"]
    Compat["packages/hunk/src/lib compatibility exports"]
    Core["Hunk core callers"]

    Git --> ExtensionAPI
    JJ --> ExtensionAPI
    Sapling --> ExtensionAPI
    Git --> VCS
    JJ --> VCS
    Sapling --> VCS
    Compat --> VCS
    Core --> Compat

Loading

Prompt To Fix All With AI

### Issue 1
packages/hunk-vcs/package.json:36
**Node Support Is Misstated**

This package declares support for Node 22+, but its exported runtime modules use Bun-only APIs such as `Bun.spawn` and `Bun.file`, and the exports point directly to TypeScript source. A Node consumer can therefore meet the stated engine requirement but fail when loading or invoking these helpers. Please remove the Node engine claim or provide and test a Node-compatible implementation.

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

_{Reviews (1): Last reviewed commit: "refactor: extract shared VCS infrastruct..." | Re-trigger Greptile}

[greptile-apps]

Node Support Is Misstated

This package declares support for Node 22+, but its exported runtime modules use Bun-only APIs such as Bun.spawn and Bun.file, and the exports point directly to TypeScript source. A Node consumer can therefore meet the stated engine requirement but fail when loading or invoking these helpers. Please remove the Node engine claim or provide and test a Node-compatible implementation.

Prompt To Fix With AI

This is a comment left during a code review.
Path: packages/hunk-vcs/package.json
Line: 36

Comment:
**Node Support Is Misstated**

This package declares support for Node 22+, but its exported runtime modules use Bun-only APIs such as `Bun.spawn` and `Bun.file`, and the exports point directly to TypeScript source. A Node consumer can therefore meet the stated engine requirement but fail when loading or invoking these helpers. Please remove the Node engine claim or provide and test a Node-compatible implementation.

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.