Babysitter codemod-executor

Execute automated AST-based code transformations for large-scale refactoring and migration

install

source · Clone the upstream repo

git clone https://github.com/a5c-ai/babysitter

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/a5c-ai/babysitter "$T" && mkdir -p ~/.claude/skills && cp -r "$T/library/specializations/code-migration-modernization/skills/codemod-executor" ~/.claude/skills/a5c-ai-babysitter-codemod-executor && rm -rf "$T"

manifest: library/specializations/code-migration-modernization/skills/codemod-executor/SKILL.md

Codemod Executor Skill

Executes automated code transformations using AST-based tools for large-scale refactoring, framework migrations, and language version upgrades.

Purpose

Enable automated code transformations for:

Framework migration (React, Angular, Vue)
Language version upgrades
API deprecation handling
Pattern standardization
Large-scale refactoring

Capabilities

1. AST-Based Transformations

Parse source code to AST
Apply transformation rules
Generate modified source
Preserve code style

2. Pattern Matching and Replacement

Define source patterns
Specify target patterns
Handle edge cases
Support wildcards and captures

3. Multi-File Transformations

Apply across entire codebase
Handle import updates
Coordinate cross-file changes
Manage side effects

4. Dry-Run Preview

Preview changes before applying
Generate diff reports
Estimate impact scope
Identify risky transformations

5. Rollback Support

Create transformation checkpoints
Enable selective rollback
Track applied codemods
Maintain change history

6. Custom Codemod Creation

Define new transformation rules
Test codemods in isolation
Document transformation logic
Share across teams

Tool Integrations

Tool	Language	Integration Method
jscodeshift	JavaScript/TypeScript	CLI
ts-morph	TypeScript	Library
Rector	PHP	CLI
Scalafix	Scala	CLI
OpenRewrite	Java	CLI / Maven
Bowler	Python	CLI
ast-grep	Multi-language	CLI / MCP
gofmt -r	Go	CLI

Output Schema

{
  "executionId": "string",
  "timestamp": "ISO8601",
  "codemod": {
    "name": "string",
    "version": "string",
    "description": "string"
  },
  "results": {
    "filesProcessed": "number",
    "filesModified": "number",
    "filesSkipped": "number",
    "transformations": "number"
  },
  "changes": [
    {
      "file": "string",
      "transformations": [
        {
          "type": "string",
          "line": "number",
          "before": "string",
          "after": "string"
        }
      ]
    }
  ],
  "errors": [],
  "warnings": []
}

Integration with Migration Processes

code-refactoring: Large-scale refactoring
framework-upgrade: Framework migrations
language-version-migration: Syntax upgrades
code-translation: Language conversion assist

Related Skills

```
refactoring-assistant
```
: Suggests transformations
```
static-code-analyzer
```
: Pre-transformation analysis

Related Agents

```
code-transformation-executor
```
: Orchestrates codemods
```
framework-upgrade-specialist
```
: Framework-specific codemods