Go Code Review

This skill provides comprehensive guidance for reviewing Go code to ensure correctness, security, performance, and best practices compliance.

Output Language

IMPORTANT: Always respond in Japanese (日本語) when performing code reviews, including:

•All explanatory text
•Problem descriptions (問題の説明)
•Impact assessments (影響の評価)
•Recommendations (推奨事項)
•Check results (チェック結果)

Keep only the following in English:

•File paths (ファイルパス)
•Code snippets (コードスニペット)
•Technical identifiers (function names, variable names, package names, etc.)

When to Use This Skill

This skill is applicable for:

•Performing code reviews on Go pull requests
•Checking Go code before merging
•Ensuring security and best practices adherence
•Validating design decisions and architecture patterns
•Performance and concurrency review

Note: Linting and auto-checkable items (syntax errors, formatting, golangci-lint) are excluded from this review as they should be caught by validation scripts or CI/CD pipelines.

Review Process

Step 1: Understand Context

Before starting the review:

•Read the PR description and linked issues
•Understand the purpose of the changes
•Check if this is new feature, bug fix, or refactoring
•Review related tests and documentation updates

Step 2: Automated Checks First

Verify automated validation has passed:

•go fmt
•go vet
•golangci-lint
•go test -race -cover
•govulncheck

If automated checks fail, request fixes before manual review.

Step 3: Systematic Review

Review categories systematically based on the changes. Use the reference documentation for detailed checks in each category.

Step 4: Report Issues

Report issues following the Output Format below, including only failed checks with specific recommendations.

Output Format

Review results must be output in structured format:

Output Elements

•
Checks (Review items checklist)
- •Display only failed review items
- •Format: ItemID ItemName: ❌ Fail
- •Purpose: Highlight issues requiring attention
- •If all checks pass, output "該当する指摘事項はありません"
•
Issues (Detected problems)
- •Display details for each failed item
- •Numbered list format for each problem
- •
  Each issue includes:
  - •Item ID + Item Name
  - •File: file path and line number
  - •Problem: Description of the issue
  - •Impact: Scope and severity
  - •Recommendation: Specific fix suggestion with code example

Output Format Example

markdown

# Go Code Review結果

## Checks

- ERR-01 Error Wrapping: ❌ Fail

## Issues

**該当する指摘事項はありません** (if all checks pass)

**OR**

1. ERR-01: エラーラップ適切
   - File: `pkg/service/processor.go` L45
   - Problem: エラー文字列のみ返却、スタックトレース欠如
   - Impact: デバッグ困難、エラー発生箇所特定不可
   - Recommendation: `fmt.Errorf("failed to process: %w", err)` でラップ

2. CTX-01: public APIでcontext受け取り
   - File: `internal/handler/api.go` L23
   - Problem: ProcessData関数がcontext.Contextを受け取っていない
   - Impact: タイムアウト制御不可、キャンセル伝播不可、テスト困難
   - Recommendation: `func ProcessData(ctx context.Context, data []byte) error` に変更

Available Review Categories

Review categories are organized by domain. Claude will read the relevant category file(s) based on the code being reviewed.

Global & Base: Package structure, imports, naming basics → reference/global.md Context Handling: context.Context propagation, timeout, cancellation → reference/context.md Concurrency: Goroutines, channels, mutexes, race conditions → reference/concurrency.md Code Standards: Naming, style, idioms, simplicity → reference/code-standards.md Function Design: Function signatures, parameters, return values → reference/function-design.md Error Handling: Error types, wrapping, sentinel errors → reference/error-handling.md Security: Input validation, crypto, SQL injection, secrets → reference/security.md Performance: Allocations, string concatenation, preallocation → reference/performance.md Testing: Test structure, table-driven tests, mocking, coverage → reference/testing.md Architecture: Package design, interfaces, dependency injection → reference/architecture.md Documentation: godoc, comments, examples → reference/documentation.md Dependencies: Module management, versioning, security → reference/dependencies.md

Best Practices

When performing code reviews:

•建設的・具体的に: コード例を含む推奨事項、共通ライブラリ参照
•コンテキスト考慮: PR目的と要件理解、トレードオフ検討
•優先度明確化: "must fix"と"nice to have"の区別
•MCPツール活用: serenaでプロジェクト構造確認、grep_searchでパターン検索
•自動チェック優先: 構文エラーやgo fmt/vet/golangci-lintへの過度な焦点回避
•セキュリティ見落とし防止: SEC-*項目は特に注意深く
•Go idiomsの重視: effective Go、common mistakesに準拠

Summary

This skill provides:

•Comprehensive review guidelines - 12 categories covering all aspects
•Structured output format - Consistent, parseable review results
•Clear process - Step-by-step review workflow
•Prioritization - Critical vs. minor issues
•Actionable recommendations - Specific fix suggestions with code examples
•Domain-specific organization - Load only relevant categories for efficient token usage

For detailed checks in each category, refer to the corresponding file in the reference/ directory.