rewrite-code

name	rewrite-code
version	0.1.0
description	Use grepwrite gw to find matches, preview code rewrites, apply transactional edits with snapshots, and undo safely
allowed-tools	Bash, Read, Grep, Glob, Edit, MultiEdit, Write

/grepwrite:rewrite-code

Use this skill when the user wants to use grepwrite (gw) for code search, safe regex or AST-aware rewrites, LLM-friendly output, transactional apply, snapshots, or undo.

Examples:

• "Use gw to find TODOs in this repo."
• "Preview replacing this API name across src."
• "Apply a safe rewrite and keep an undo snapshot."
• "Undo the last grepwrite rewrite."
• "Use caveman output for a compact agent-readable match list."

Install

cargo install grepwrite

Confirm:

gw --help

gw wraps ripgrep-style search and adds a transactional rewrite layer with snapshots.

Search Workflow

Find matches:

gw find 'pattern' src/

Use output formats deliberately:

gw find 'pattern' src/ -o compact
gw find 'pattern' src/ -o caveman
gw find 'pattern' src/ -o json

Use caveman when you need a token-minimal path:line list for an agent. Use json when scripting or post-processing.

AST-aware search:

gw find 'pattern' src/ --in function
gw find 'pattern' src/ --in class
gw find 'pattern' src/ --in imports
gw find 'pattern' src/ --in comments

Rewrite Workflow

Preview first. Rewrites are dry-run by default:

gw rewrite 'oldName' 'newName' src/ -o diff

Review the diff. If it is correct, apply:

gw rewrite 'oldName' 'newName' src/ --apply

Applied rewrites are atomic per file and wrapped in a git-ref snapshot. Record the snapshot ID in your notes when coordinating multi-step work.

Undo

List snapshots:

gw snapshots

Undo the latest snapshot:

gw undo

Undo a specific snapshot:

gw undo --snapshot SNAPSHOT_ID

gw undo refuses to clobber edits made after the snapshot. If undo fails, inspect the reported files and decide whether to revert manually.

Agent-Safe Rules

• Always preview rewrites before --apply.
• Use narrow paths first, such as src/ or a specific package.
• Do not use broad root rewrites until the preview is reviewed.
• Prefer -o diff for human review and -o json for tooling.
• Use AST constraints when a plain regex risks touching comments, strings, or unrelated contexts.
• After --apply, run the project’s relevant tests or type checks.
• Keep snapshot IDs in the final report for applied changes.

Common Patterns

Find candidate identifiers:

gw find '\boldName\b' src/ -o compact

Preview a rename:

gw rewrite '\boldName\b' 'newName' src/ -o diff

Apply after review:

gw rewrite '\boldName\b' 'newName' src/ --apply

Search imports only:

gw find 'old-package' src/ --in imports -o compact

Validation

After applied rewrites, run the target repo’s checks. Examples:

cargo test
pnpm test
go test ./...
just check

If validation fails, inspect the failure before using undo; sometimes the rewrite is correct and only a follow-up adjustment is needed.