ast-grep

ast-grep Plugin

AST-based code structural search, lint, and rewriting.

Commands

Search

• ast-grep search run — Search using AST pattern

Rewrite

• ast-grep rewrite run — Rewrite code using pattern and replacement

Lint

• ast-grep lint run — Run linting rules
• ast-grep scan run — Scan directory with rules

Usage Examples

• "Find all usages of $A && $A() pattern in TypeScript"
• "Replace null coalescing patterns"
• "Lint the codebase for specific patterns"
• "Scan src directory for violations"

Installation

npm install --global @ast-grep/cli
# or
cargo install ast-grep
# or
brew install ast-grep

Examples

# Search for AST pattern
ast-grep --pattern 'const $X = $Y' --lang ts

# Rewrite code
ast-grep --pattern '$A && $A()' --lang ts --rewrite '$A?.()'

# Run lint
ast-grep lint

# Scan directory
ast-grep scan src/

Key Features

• Pattern looks like real code
• Supports JS, TS, Python, Rust, Go, Java, etc.
• Use $VAR as wildcard for AST nodes
• YAML-based lint rules -批量 code rewriting