structural-search

Original：🇺🇸 English
Translated

Search code by AST structure using ast-grep. Find semantic patterns like function calls, imports, class definitions instead of text patterns. Triggers on: find all calls to X, search for pattern, refactor usages, find where function is used, structural search, ast-grep, sg.

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Source0xdarkmatter/claude-mods
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NPX Install

npx skill4agent add 0xdarkmatter/claude-mods structural-search

Tags

Translated version includes tags in frontmatter
ast-grepstructural-code-searchcode-refactoringpattern-matchingcode-quality-checking

SKILL.md Content

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Structural Search

Search code by its abstract syntax tree (AST) structure. Finds semantic patterns that regex cannot match reliably.

Tools

ToolCommandUse For
ast-grep
sg -p 'pattern'
AST-aware code search

Pattern Syntax

PatternMatchesExample
$NAME
Named identifier
function $NAME() {}
$_
Any single node
console.log($_)
$$$
Zero or more nodes
function $_($$$) {}

Top 10 Essential Patterns

bash
# 1. Find console.log calls
sg -p 'console.log($_)'

# 2. Find React hooks
sg -p 'const [$_, $_] = useState($_)'
sg -p 'useEffect($_, [$$$])'

# 3. Find function definitions
sg -p 'function $NAME($$$) { $$$ }'
sg -p 'def $NAME($$$): $$$' --lang python

# 4. Find imports
sg -p 'import $_ from "$_"'
sg -p 'from $_ import $_' --lang python

# 5. Find async patterns
sg -p 'await $_'
sg -p 'async function $NAME($$$) { $$$ }'

# 6. Find error handling
sg -p 'try { $$$ } catch ($_) { $$$ }'
sg -p 'if err != nil { $$$ }' --lang go

# 7. Find potential issues
sg -p '$_ == $_'           # == instead of ===
sg -p 'eval($_)'           # Security risk
sg -p '$_.innerHTML = $_'  # XSS vector

# 8. Preview refactoring
sg -p 'console.log($_)' -r 'logger.info($_)'

# 9. Apply refactoring
sg -p 'var $NAME = $_' -r 'const $NAME = $_' --rewrite

# 10. Search specific language
sg -p 'pattern' --lang typescript

Quick Reference

TaskCommand
Find pattern
sg -p 'pattern'
Specific language
sg -p 'pattern' --lang python
Replace (preview)
sg -p 'old' -r 'new'
Replace (apply)
sg -p 'old' -r 'new' --rewrite
Show context
sg -p 'pattern' -A 3
JSON output
sg -p 'pattern' --json
File list only
sg -p 'pattern' -l
Count matches
sg -p 'pattern' --count
Run YAML rules
sg scan

When to Use

  • Finding all usages of a function/method
  • Locating specific code patterns (hooks, API calls)
  • Preparing for large-scale refactoring
  • When regex would match false positives
  • Detecting anti-patterns and security issues
  • Creating custom linting rules

Additional Resources

For complete patterns, load:
  • ./references/js-ts-patterns.md
    - JavaScript/TypeScript patterns
  • ./references/python-patterns.md
    - Python patterns
  • ./references/go-rust-patterns.md
    - Go and Rust patterns
  • ./references/security-patterns.md
    - Security vulnerability detection
  • ./references/advanced-usage.md
    - YAML rules and tool integration
  • ./assets/rule-template.yaml
    - Starter template for custom rules