Code Search Tool Selection

Use this skill to choose the search or refactoring tool. After selecting ast-grep, load ast-grep; that skill owns pattern syntax, rewrites, repository rule setup, tests, severity, and CI.

ast-grep vs ripgrep

When to Use ast-grep

Use ast-grep when structure matters. It parses code and matches AST nodes, so results ignore comments/strings, understand syntax, and scope rewrites to matched code.

Best for:

• Refactors/codemods: rename APIs, change import forms, rewrite call sites or variable kinds
• Policy checks: enforce patterns across a repo (scan with rules + test)
• Editor diagnostics and automation: LSP mode; structured JSON output
• Syntax-structured code changes after previewing the matches

When to Use ripgrep

Use ripgrep when text is enough. It's the fastest way to grep literals/regex across files.

Best for:

• Recon: find strings, TODOs, log lines, config values, or non‑code assets
• Pre-filter: narrow candidate files before a precise pass
• Quick searches where you just need to find text

Rule of Thumb

• Need a syntax-structured code change → start with ast-grep
• Need raw speed or you're just hunting text → start with rg
• Often combine: rg to shortlist files, then ast-grep to match/modify with precision

ripgrep examples

Quick textual hunt:

rg -n 'console\.log\(' -t js

Find in specific file types:

rg 'TODO|FIXME' -t py -t js

Context around matches:

rg -C 3 'error' -t log

List files with matches:

rg -l 'import.*React' -t tsx

Mental Model

Aspect	ast-grep	ripgrep
Unit of match	AST node	Line
False positives	Low (understands syntax)	Depends on regex
Rewrites	Syntax-scoped	Text replacement, risky
Speed	Slower (parses code)	Fastest (text only)
Use case	Structural search/refactor	Text search/grep

Quick Decision Tree

Need to change syntax-structured code?
├─ Yes → ast-grep
└─ No
   ├─ Searching code structure? → ast-grep
   └─ Just finding text? → ripgrep

Selection examples

• Find function definitions by syntax → use ast-grep, then load ast-grep.
• Refactor API calls → use ast-grep; do not use text replacement.
• Find TODOs, log messages, or configuration values → use ripgrep.