ast-grep-cheatsheet-ja.yaml

# ast-grep 使用例チートシート

# ==========================================
# 基本的なパターンマッチング
# ==========================================

# 1. 関数呼び出しの検索
# CLI: ast-grep -p 'console.log($MSG)' src/
id: find-console-log
language: JavaScript
rule:
  pattern: console.log($MSG)

---
# 2. 関数定義の検索（各種パターン）
# CLI: ast-grep -p 'function $NAME($$) { $$ }' src/
id: find-function-definitions
language: JavaScript
rule:
  any:
    # 通常の関数定義
    - pattern: function $NAME($$PARAMS) { $$BODY }
    # アロー関数（ブロック形式）
    - pattern: const $NAME = ($$PARAMS) => { $$BODY }
    # アロー関数（式形式）
    - pattern: const $NAME = ($$PARAMS) => $EXPR
    # オブジェクトメソッド
    - pattern: $NAME($$PARAMS) { $$BODY }
    # クラスメソッド
    - pattern: |
      class $CLASS {
        $NAME($$PARAMS) { $$BODY }
      }
    # 非同期関数
    - pattern: async function $NAME($$PARAMS) { $$BODY }
    - pattern: const $NAME = async ($$PARAMS) => { $$BODY }

---
# 3. exportされたシンボルの検索
# CLI: ast-grep -p 'export $SYMBOL' src/
id: find-exported-symbols
language: JavaScript
rule:
  any:
    # 名前付きexport
    - pattern: export { $$SYMBOLS }
    # デフォルトexport（関数）
    - pattern: export default function $NAME($$) { $$ }
    # デフォルトexport（変数）
    - pattern: export default $VALUE
    # 宣言と同時にexport
    - pattern: export const $NAME = $VALUE
    - pattern: export function $NAME($$) { $$ }
    - pattern: export class $NAME { $$ }
    # 再export
    - pattern: export { $$SYMBOLS } from $MODULE
    - pattern: export * from $MODULE
    # 型export（TypeScript）
    - pattern: export type $TYPE = $DEF
    - pattern: export interface $INTERFACE { $$ }

---
# 4. 特定の関数シグネチャ検索
# CLI: ast-grep -p 'function $NAME(req, res) { $$ }' src/
id: find-express-handlers
language: JavaScript
rule:
  any:
    - pattern: function $NAME(req, res) { $$BODY }
    - pattern: const $NAME = (req, res) => { $$BODY }
    - pattern: app.$METHOD($PATH, (req, res) => { $$BODY })
message: "Express ハンドラー関数"

---
# 5. 変数宣言の検索（任意の宣言タイプ）
# CLI: 複数パターンはYAMLでのみ対応
id: find-var-declarations
language: JavaScript
rule:
  any:
    - pattern: var $NAME = $VALUE
    - pattern: let $NAME = $VALUE
    - pattern: const $NAME = $VALUE

---
# 6. 特定のASTノード種別
# CLI: ast-grep --kind field_definition src/
id: find-class-fields
language: JavaScript
rule:
  kind: field_definition

---
# ==========================================
# 検索と置換
# ==========================================

# 7. オプショナルチェーンへの変換
# CLI: ast-grep -p '$PROP && $PROP()' --rewrite '$PROP?.()' --interactive src/
id: use-optional-chaining
language: TypeScript
rule:
  pattern: $PROP && $PROP()
fix: $PROP?.()

---
# 8. console.logの削除
# CLI: ast-grep -p 'console.log($$)' --rewrite '' --interactive src/
id: remove-console-log
language: JavaScript
rule:
  pattern: console.log($$ARGS)
fix: ""
message: "console.logは本番環境では削除してください"

---
# 9. 古いPromise構文を async/await に変換
# CLI: 複雑なため、YAMLでのみ対応
id: promise-to-async
language: JavaScript
rule:
  pattern: $FUNC().then($CALLBACK)
fix: await $FUNC()
note: "コールバック関数の処理は手動で調整が必要です"

---
# ==========================================
# 関係性ルール（inside, has, follows, precedes）
# ==========================================

# 10. ループ内のawait検出
# CLI: 複雑なため、YAMLでのみ対応
id: no-await-in-loop
language: TypeScript
severity: warning
rule:
  pattern: await $PROMISE
  inside:
    any:
      - kind: for_statement
      - kind: while_statement
      - kind: for_in_statement
      - kind: for_of_statement
    stopBy: end
message: "ループ内でのawaitは性能問題を引き起こします"

---
# 11. 返り値のない関数検出
# CLI: 複雑なため、YAMLでのみ対応
id: function-without-return
language: JavaScript
rule:
  pattern: function $NAME($$PARAMS) { $$BODY }
  not:
    has:
      pattern: return $VALUE

---
# 12. try-catch内のconsole.log検出
# CLI: 複雑なため、YAMLでのみ対応
id: console-in-catch
language: JavaScript
rule:
  pattern: console.log($MSG)
  inside:
    pattern: catch ($ERROR) { $$BODY }
    selector: block

---
# ==========================================
# 正規表現とテキストマッチング
# ==========================================

# 13. React Hooks命名規則チェック
# CLI: 制約条件があるため、YAMLでのみ対応
id: react-hooks-naming
language: TypeScript
rule:
  pattern: function $NAME($$) { $$ }
  has:
    any:
      - pattern: useState($$)
      - pattern: useEffect($$)
      - pattern: useMemo($$)
constraints:
  NAME:
    regex: '^use[A-Z]'
    not: true
message: "React Hooksは'use'で始まる必要があります"

---
# 14. TODOコメントの検出
# CLI: ast-grep -p '// TODO: $MSG' src/
id: find-todo-comments
language: JavaScript
rule:
  regex: 'TODO:|FIXME:|HACK:'
  kind: comment

---
# ==========================================
# 複合条件（all, any, not）
# ==========================================

# 15. 特定の条件を満たすif文
# CLI: 複雑なため、YAMLでのみ対応
id: suspicious-if-statement
language: JavaScript
rule:
  all:
    - pattern: if ($CONDITION) { $BODY }
    - has:
        pattern: $CONDITION
        regex: '==|!='
  not:
    has:
      pattern: $CONDITION
      regex: '===|!=='
message: "厳密等価演算子(===, !==)を使用してください"

---
# 16. 空のcatch文
# CLI: ast-grep -p 'catch ($ERROR) {}' src/
id: empty-catch-block
language: JavaScript
rule:
  all:
    - pattern: catch ($ERROR) { $$BODY }
    - not:
        has:
          any:
            - kind: expression_statement
            - kind: throw_statement
            - kind: return_statement

---
# ==========================================
# 位置指定（nthChild）
# ==========================================

# 17. 配列の最初の要素
# CLI: 位置指定はYAMLでのみ対応
id: first-array-element
language: JavaScript
rule:
  kind: string
  nthChild: 1
  inside:
    kind: array

---
# 18. 関数の第2引数
# CLI: 位置指定はYAMLでのみ対応
id: second-function-argument
language: JavaScript
rule:
  nthChild: 2
  inside:
    kind: arguments

---
# ==========================================
# ユーティリティルールの活用
# ==========================================

# 19. 共通パターンの定義と再利用
# CLI: ユーティリティルールはYAMLでのみ対応
utils:
  is-literal:
    any:
      - kind: string
      - kind: number
      - kind: boolean
      - kind: null
      - kind: undefined
  
  is-console-method:
    pattern: console.$METHOD($$ARGS)
  
  is-react-component:
    any:
      - pattern: function $NAME() { return $JSX }
      - pattern: const $NAME = () => $JSX
      - pattern: class $NAME extends Component { $$ }

id: check-hardcoded-values
language: JavaScript
rule:
  matches: is-literal
  inside:
    matches: is-react-component
message: "コンポーネント内でハードコードされた値を使用しています"

---
# ==========================================
# 言語固有のパターン
# ==========================================

# 20. Python: print文をloggingに変換
# CLI: ast-grep -p 'print($MSG)' --rewrite 'logger.info($MSG)' --interactive *.py
id: use-logging-python
language: Python
rule:
  pattern: print($MSG)
fix: logger.info($MSG)

---
# 21. Java: nullチェック不足
# CLI: 複雑なため、YAMLでのみ対応
id: missing-null-check
language: Java
rule:
  pattern: $OBJ.$METHOD()
  not:
    precedes:
      any:
        - pattern: if ($OBJ != null)
        - pattern: if (null != $OBJ)
        - pattern: Objects.nonNull($OBJ)

---
# 22. Go: エラーハンドリング
# CLI: 複雑なため、YAMLでのみ対応
id: go-error-handling
language: Go
rule:
  pattern: $VAR, err := $CALL
  not:
    follows:
      pattern: if err != nil { $$ }
message: "エラーハンドリングが不足しています"

---
# ==========================================
# セキュリティパターン
# ==========================================

# 23. 危険なevalの使用
# CLI: ast-grep -p 'eval($CODE)' src/
id: dangerous-eval
language: JavaScript
severity: error
rule:
  pattern: eval($CODE)
message: "evalの使用は危険です"

---
# 24. SQLインジェクションの可能性
# CLI: 複雑なため、YAMLでのみ対応
id: sql-injection-risk
language: JavaScript
rule:
  pattern: $DB.query($QUERY)
  has:
    pattern: $QUERY
    regex: '.*\+.*|.*\$\{.*\}.*'
message: "SQLインジェクションの可能性があります。パラメータ化クエリを使用してください"

---
# ==========================================
# パフォーマンスパターン
# ==========================================

# 25. ループ内のDOM操作
# CLI: 複雑なため、YAMLでのみ対応
id: dom-in-loop
language: JavaScript
rule:
  pattern: document.$METHOD($$)
  inside:
    any:
      - kind: for_statement
      - kind: while_statement
      - kind: for_in_statement
message: "ループ内でのDOM操作は性能問題を引き起こします"

---
# 26. 不要なre-render（React）
# CLI: 複雑なため、YAMLでのみ対応
id: unnecessary-rerender
language: TypeScript
rule:
  pattern: useEffect(() => { $$BODY }, [])
  has:
    pattern: setState($VALUE)
message: "useEffect内でのstate更新は無限ループを引き起こす可能性があります"

---
# ==========================================
# コード品質パターン
# ==========================================

# 27. 長すぎる関数
# CLI: 複雑なため、YAMLでのみ対応
id: long-function
language: JavaScript
rule:
  pattern: function $NAME($$) { $$BODY }
constraints:
  BODY:
    regex: '(\n.*){20,}'
message: "関数が長すぎます。分割を検討してください"

---
# 28. マジックナンバー
# CLI: ast-grep -p '$VAR > 100' src/ （具体的な数値指定）
id: magic-numbers
language: JavaScript
rule:
  kind: number
  regex: '^(?!0|1|2|10|100).*'
  not:
    inside:
      kind: const_statement
message: "マジックナンバーは定数として定義してください"

---
# ==========================================
# 実行用の設定例
# ==========================================

# プロジェクト全体をチェック
# CLI: ast-grep scan

# 特定のルールのみ実行
# CLI: ast-grep scan -r specific-rule.yml

# インタラクティブ修正
# CLI: ast-grep scan --interactive

# JSON出力
# CLI: ast-grep scan --json | jq

# デバッグモード
# CLI: ast-grep run --debug-query -p 'pattern'

ast-grep-cheetsheet-en.yaml

# ==========================================
# Basic Pattern Matching
# ==========================================

# 1. Function call search
# CLI: ast-grep -p 'console.log($MSG)' src/
id: find-console-log
language: JavaScript
rule:
  pattern: console.log($MSG)

---
# 2. Function definition search (various patterns)
# CLI: ast-grep -p 'function $NAME($$$) { $$$$ }' src/
id: find-function-definitions
language: JavaScript
rule:
  any:
    # Regular function definition
    - pattern: function $NAME($$$PARAMS) { $$$BODY }
    # Arrow function (block form)
    - pattern: const $NAME = ($$$PARAMS) => { $$$BODY }
    # Arrow function (expression form)
    - pattern: const $NAME = ($$$PARAMS) => $EXPR
    # Object method
    - pattern: $NAME($$$PARAMS) { $$$BODY }
    # Class method
    - pattern: |
      class $CLASS {
        $NAME($$$PARAMS) { $$$BODY }
      }
    # Async function
    - pattern: async function $NAME($$$PARAMS) { $$$BODY }
    - pattern: const $NAME = async ($$$PARAMS) => { $$$BODY }

---
# 3. Exported symbols search
# CLI: ast-grep -p 'export $SYMBOL' src/
id: find-exported-symbols
language: JavaScript
rule:
  any:
    # Named export
    - pattern: export { $$$SYMBOLS }
    # Default export (function)
    - pattern: export default function $NAME($$$) { $$$$ }
    # Default export (variable)
    - pattern: export default $VALUE
    # Export with declaration
    - pattern: export const $NAME = $VALUE
    - pattern: export function $NAME($$$) { $$$$ }
    - pattern: export class $NAME { $$$$ }
    # Re-export
    - pattern: export { $$$SYMBOLS } from $MODULE
    - pattern: export * from $MODULE
    # Type export (TypeScript)
    - pattern: export type $TYPE = $DEF
    - pattern: export interface $INTERFACE { $$$$ }

---
# 4. Specific function signature search
# CLI: ast-grep -p 'function $NAME(req, res) { $$$$ }' src/
id: find-express-handlers
language: JavaScript
rule:
  any:
    - pattern: function $NAME(req, res) { $$$BODY }
    - pattern: const $NAME = (req, res) => { $$$BODY }
    - pattern: app.$METHOD($PATH, (req, res) => { $$$BODY })
message: "Express handler function"

---
# 5. Variable declaration search (any declaration type)
# CLI: Multiple patterns only supported in YAML
id: find-var-declarations
language: JavaScript
rule:
  any:
    - pattern: var $NAME = $VALUE
    - pattern: let $NAME = $VALUE
    - pattern: const $NAME = $VALUE

---
# 6. Specific AST node kind
# CLI: ast-grep --kind field_definition src/
id: find-class-fields
language: JavaScript
rule:
  kind: field_definition

---
# ==========================================
# Search and Replace
# ==========================================

# 7. Convert to optional chaining
# CLI: ast-grep -p '$PROP && $PROP()' --rewrite '$PROP?.()' --interactive src/
id: use-optional-chaining
language: TypeScript
rule:
  pattern: $PROP && $PROP()
fix: $PROP?.()

---
# 8. Remove console.log
# CLI: ast-grep -p 'console.log($$$)' --rewrite '' --interactive src/
id: remove-console-log
language: JavaScript
rule:
  pattern: console.log($$$ARGS)
fix: ""
message: "console.log should be removed in production"

---
# 9. Convert old Promise syntax to async/await
# CLI: Complex pattern, YAML only
id: promise-to-async
language: JavaScript
rule:
  pattern: $FUNC().then($CALLBACK)
fix: await $FUNC()
note: "Callback function handling requires manual adjustment"

---
# ==========================================
# Relational Rules (inside, has, follows, precedes)
# ==========================================

# 10. Detect await in loops
# CLI: Complex pattern, YAML only
id: no-await-in-loop
language: TypeScript
severity: warning
rule:
  pattern: await $PROMISE
  inside:
    any:
      - kind: for_statement
      - kind: while_statement
      - kind: for_in_statement
      - kind: for_of_statement
    stopBy: end
message: "await in loops can cause performance issues"

---
# 11. Functions without return value
# CLI: Complex pattern, YAML only
id: function-without-return
language: JavaScript
rule:
  pattern: function $NAME($$$PARAMS) { $$$BODY }
  not:
    has:
      pattern: return $VALUE

---
# 12. console.log in try-catch
# CLI: Complex pattern, YAML only
id: console-in-catch
language: JavaScript
rule:
  pattern: console.log($MSG)
  inside:
    pattern: catch ($ERROR) { $$$BODY }
    selector: block

---
# ==========================================
# Regular Expression and Text Matching
# ==========================================

# 13. React Hooks naming convention check
# CLI: Constraints required, YAML only
id: react-hooks-naming
language: TypeScript
rule:
  pattern: function $NAME($$$) { $$$$ }
  has:
    any:
      - pattern: useState($$$)
      - pattern: useEffect($$$)
      - pattern: useMemo($$$)
constraints:
  NAME:
    regex: '^use[A-Z]'
    not: true
message: "React Hooks must start with 'use'"

---
# 14. TODO comment detection
# CLI: ast-grep -p '// TODO: $MSG' src/
id: find-todo-comments
language: JavaScript
rule:
  regex: 'TODO:|FIXME:|HACK:'
  kind: comment

---
# ==========================================
# Composite Conditions (all, any, not)
# ==========================================

# 15. Suspicious if statements
# CLI: Complex pattern, YAML only
id: suspicious-if-statement
language: JavaScript
rule:
  all:
    - pattern: if ($CONDITION) { $BODY }
    - has:
        pattern: $CONDITION
        regex: '==|!='
  not:
    has:
      pattern: $CONDITION
      regex: '===|!=='
message: "Use strict equality operators (===, !==)"

---
# 16. Empty catch blocks
# CLI: ast-grep -p 'catch ($ERROR) {}' src/
id: empty-catch-block
language: JavaScript
rule:
  all:
    - pattern: catch ($ERROR) { $$$BODY }
    - not:
        has:
          any:
            - kind: expression_statement
            - kind: throw_statement
            - kind: return_statement

---
# ==========================================
# Position Specification (nthChild)
# ==========================================

# 17. First array element
# CLI: Position specification only in YAML
id: first-array-element
language: JavaScript
rule:
  kind: string
  nthChild: 1
  inside:
    kind: array

---
# 18. Second function argument
# CLI: Position specification only in YAML
id: second-function-argument
language: JavaScript
rule:
  nthChild: 2
  inside:
    kind: arguments

---
# ==========================================
# Utility Rule Usage
# ==========================================

# 19. Common pattern definition and reuse
# CLI: Utility rules only in YAML
utils:
  is-literal:
    any:
      - kind: string
      - kind: number
      - kind: boolean
      - kind: null
      - kind: undefined
  
  is-console-method:
    pattern: console.$METHOD($$$ARGS)
  
  is-react-component:
    any:
      - pattern: function $NAME() { return $JSX }
      - pattern: const $NAME = () => $JSX
      - pattern: class $NAME extends Component { $$$$ }

id: check-hardcoded-values
language: JavaScript
rule:
  matches: is-literal
  inside:
    matches: is-react-component
message: "Hardcoded values used in component"

---
# ==========================================
# Language-Specific Patterns
# ==========================================

# 20. Python: Convert print to logging
# CLI: ast-grep -p 'print($MSG)' --rewrite 'logger.info($MSG)' --interactive *.py
id: use-logging-python
language: Python
rule:
  pattern: print($MSG)
fix: logger.info($MSG)

---
# 21. Java: Missing null check
# CLI: Complex pattern, YAML only
id: missing-null-check
language: Java
rule:
  pattern: $OBJ.$METHOD()
  not:
    precedes:
      any:
        - pattern: if ($OBJ != null)
        - pattern: if (null != $OBJ)
        - pattern: Objects.nonNull($OBJ)

---
# 22. Go: Error handling
# CLI: Complex pattern, YAML only
id: go-error-handling
language: Go
rule:
  pattern: $VAR, err := $CALL
  not:
    follows:
      pattern: if err != nil { $$$$ }
message: "Missing error handling"

---
# ==========================================
# Security Patterns
# ==========================================

# 23. Dangerous eval usage
# CLI: ast-grep -p 'eval($CODE)' src/
id: dangerous-eval
language: JavaScript
severity: error
rule:
  pattern: eval($CODE)
message: "eval usage is dangerous"

---
# 24. SQL injection possibility
# CLI: Complex pattern, YAML only
id: sql-injection-risk
language: JavaScript
rule:
  pattern: $DB.query($QUERY)
  has:
    pattern: $QUERY
    regex: '.*\+.*|.*\$\{.*\}.*'
message: "Possible SQL injection. Use parameterized queries"

---
# ==========================================
# Performance Patterns
# ==========================================

# 25. DOM operations in loops
# CLI: Complex pattern, YAML only
id: dom-in-loop
language: JavaScript
rule:
  pattern: document.$METHOD($$$)
  inside:
    any:
      - kind: for_statement
      - kind: while_statement
      - kind: for_in_statement
message: "DOM operations in loops can cause performance issues"

---
# 26. Unnecessary re-render (React)
# CLI: Complex pattern, YAML only
id: unnecessary-rerender
language: TypeScript
rule:
  pattern: useEffect(() => { $$$BODY }, [])
  has:
    pattern: setState($VALUE)
message: "State updates in useEffect can cause infinite loops"

---
# ==========================================
# Code Quality Patterns
# ==========================================

# 27. Functions that are too long
# CLI: Complex pattern, YAML only
id: long-function
language: JavaScript
rule:
  pattern: function $NAME($$$) { $$$BODY }
constraints:
  BODY:
    regex: '(\n.*){20,}'
message: "Function is too long. Consider splitting"

---
# 28. Magic numbers
# CLI: ast-grep -p '$VAR > 100' src/ (specific number)
id: magic-numbers
language: JavaScript
rule:
  kind: number
  regex: '^(?!0|1|2|10|100).*'
  not:
    inside:
      kind: const_statement
message: "Magic numbers should be defined as constants"

---
# ==========================================
# Execution Configuration Examples
# ==========================================

# Check entire project
# CLI: ast-grep scan

# Run specific rule only
# CLI: ast-grep scan -r specific-rule.yml

# Interactive fixing
# CLI: ast-grep scan --interactive

# JSON output
# CLI: ast-grep scan --json | jq

# Debug mode
# CLI: ast-grep run --debug-query -p 'pattern'