feat: add @ast-grep/lang-systemverilog package

[babyworm]

As suggested in ast-grep/ast-grep#2477 (comment), adding the NAPI language package to langs.

Summary

• Add @ast-grep/lang-systemverilog for NAPI SystemVerilog support (.v, .vh, .sv, .svh)
• Uses tree-sitter-systemverilog v0.3.1 via GitHub URL (not published on npm)
• expandoChar: '_' — $ is reserved for SystemVerilog system tasks (IEEE 1800-2017 §5.6)

Test plan

• pnpm source / pnpm build / pnpm test all pass
• Nursery tests: module parsing, pattern matching (module_declaration), $display parsing, always_ff pattern
• oxlint clean (0 warnings, 0 errors)

Summary by CodeRabbit

• New Features
  • Introduced SystemVerilog language support for ast-grep, enabling pattern matching and abstract syntax tree analysis for SystemVerilog code.
  • Supports file extensions: .v, .vh, .sv, .svh.
  • Includes comprehensive documentation and setup instructions for integration.

[coderabbitai]

📝 Walkthrough

Walkthrough

This PR introduces SystemVerilog language support to ast-grep by adding a new language package with parser configuration, runtime initialization, TypeScript definitions, setup automation, and test coverage for SystemVerilog file extensions (.v, .vh, .sv, .svh).

Changes

Cohort / File(s)	Summary
Package Configuration packages/systemverilog/package.json, packages/systemverilog/postinstall.js	New package manifest defining build, test, and postinstall scripts; runtime dependency on @ast-grep/setup-lang; postinstall hook for automated setup.
Language Integration packages/systemverilog/index.js, packages/systemverilog/index.d.ts	JavaScript module with lazy-loaded parser path resolution and configuration object exposing libraryPath, extensions (v, vh, sv, svh), languageSymbol, and expandoChar; TypeScript type definitions for LanguageRegistration.
Documentation and Testing packages/systemverilog/README.md, packages/systemverilog/nursery.js	README with installation and usage instructions; nursery test file covering module parsing, pattern matching for modules and always_ff blocks, and system task parsing.
Changelog .changeset/add-systemverilog.md	Changeset entry documenting minor version bump for @ast-grep/lang-systemverilog with SystemVerilog file extension support.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• feat: C# language #41: Adds a new language package following the same structural pattern with index.js, index.d.ts with LanguageRegistration, README, nursery tests, package.json, and postinstall setup.

Suggested reviewers

• HerringtonDarkholme

Poem

🐰 A new language hops into our warren,
SystemVerilog files (.v, .vh, .sv, .svh) now welcomed with care,
Parser paths dance with lazy precision,
Tests verify each pattern match and declaration—
Ast-grep's garden grows more verdant! 🌿

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% 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
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately reflects the main change: adding a new SystemVerilog language package to the ast-grep project.

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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

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[coderabbitai]

🧹 Nitpick comments (1)

packages/systemverilog/package.json (1)

41-41: Consider pinning tree-sitter-systemverilog to a commit SHA instead of a tag.

Git tags are mutable and can be force-pushed. For truly reproducible builds, a commit SHA (github:gmlarumbe/tree-sitter-systemverilog#<SHA>) is immutable.

♻️ Example

-    "tree-sitter-systemverilog": "github:gmlarumbe/tree-sitter-systemverilog#v0.3.1"
+    "tree-sitter-systemverilog": "github:gmlarumbe/tree-sitter-systemverilog#<commit-sha-for-v0.3.1>"

🤖 Prompt for AI Agents

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

In `@packages/systemverilog/package.json` at line 41, The dependency
"tree-sitter-systemverilog" in packages/systemverilog/package.json is using a
mutable tag; change the value from
"github:gmlarumbe/tree-sitter-systemverilog#v0.3.1" to the corresponding
immutable commit SHA (e.g.
"github:gmlarumbe/tree-sitter-systemverilog#<COMMIT_SHA>") so installs are
reproducible—locate the package.json entry for "tree-sitter-systemverilog",
replace the tag with the exact commit SHA that matches v0.3.1 (or the desired
commit), and save/update lockfile.

🤖 Prompt for all review comments with AI agents

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

Nitpick comments:
In `@packages/systemverilog/package.json`:
- Line 41: The dependency "tree-sitter-systemverilog" in
packages/systemverilog/package.json is using a mutable tag; change the value
from "github:gmlarumbe/tree-sitter-systemverilog#v0.3.1" to the corresponding
immutable commit SHA (e.g.
"github:gmlarumbe/tree-sitter-systemverilog#<COMMIT_SHA>") so installs are
reproducible—locate the package.json entry for "tree-sitter-systemverilog",
replace the tag with the exact commit SHA that matches v0.3.1 (or the desired
commit), and save/update lockfile.

---

ℹ️ Review info

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 1fdb7f6 and 09d4781.

⛔ Files ignored due to path filters (1)

• pnpm-lock.yaml is excluded by !**/pnpm-lock.yaml

📒 Files selected for processing (7)

• .changeset/add-systemverilog.md
• packages/systemverilog/README.md
• packages/systemverilog/index.d.ts
• packages/systemverilog/index.js
• packages/systemverilog/nursery.js
• packages/systemverilog/package.json
• packages/systemverilog/postinstall.js

[HerringtonDarkholme]

can you release it on npm instead of github?

[HerringtonDarkholme]

node-gyp should not be added as dependencies.

I suspect tree-sitter-verilog is doing great here