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mikulgohilmikulgohil/claude-skills/skills/devex/structural-search/SKILL.md

structural-search

Skill0 starsChanged 5 months agoMITView on GitHub

Search and rewrite code by AST structure using ast-grep — match function calls, imports, and class definitions semantically rather than by text. Use for precise, codebase-wide refactors. Requires the ast-grep (sg) CLI.

2 other projects use a version of this.

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2 rules. About 0 are common, 2 are distinctive, and 0 are very specific to this project.

  • ≈0

    Common · estimate

    Many files like this have a rule of this kind.

  • ≈2

    Distinctive · estimate

    This author's own choices. Worth a look.

  • 0

    Very specific

    Tied to their project's names, files or tools. Probably skip.

  • Common
  • Distinctive
  • Very specific
  1. Distinctive:

    Search code by its abstract syntax tree (AST) structure.

    line 13
  2. Distinctive:

    When regex would match false positives

    line 89

≈ “Common” is an estimate: at least 1 in 5 of the 350,495 skill files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.

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Files
SKILL.md

Structural Search

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

Tools

ToolCommandUse For
ast-grepsg -p 'pattern'AST-aware code search

Pattern Syntax

PatternMatchesExample
$NAMENamed identifierfunction $NAME() {}
$_Any single nodeconsole.log($_)
$$$Zero or more nodesfunction $_($$$) {}

Top 10 Essential Patterns

# 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 patternsg -p 'pattern'
Specific languagesg -p 'pattern' --lang python
Replace (preview)sg -p 'old' -r 'new'
Replace (apply)sg -p 'old' -r 'new' --rewrite
Show contextsg -p 'pattern' -A 3
JSON outputsg -p 'pattern' --json
File list onlysg -p 'pattern' -l
Count matchessg -p 'pattern' --count
Run YAML rulessg 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-ops.md - Security vulnerability detection
  • ./references/advanced-usage.md - YAML rules and tool integration
  • ./assets/rule-template.yaml - Starter template for custom rules

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