Codemod Generator Skill

Overview

This skill generates automated code migration scripts (codemods) that transform consumer code to use new API versions, reducing the burden of SDK upgrades on developers.

Capabilities

• Create AST-based code transformations
• Support multiple languages (JavaScript, TypeScript, Python, Go)
• Provide dry-run mode with change preview
• Implement safe rollback mechanisms
• Generate detailed migration reports
• Handle edge cases and partial migrations
• Support interactive migration modes
• Validate transformations with tests

Target Processes

• Backward Compatibility Management
• Package Distribution
• SDK Versioning and Release Management

Integration Points

• jscodeshift for JavaScript/TypeScript
• libcst for Python
• go-codemod for Go
• Rector for PHP
• Custom AST transformers

Input Requirements

• Source and target API versions
• Transformation rules specification
• Test cases for validation
• Edge case handling requirements
• Rollback strategy

Output Artifacts

• Codemod scripts per language
• Dry-run reports
• Migration validation tests
• Edge case documentation
• CLI wrapper for execution
• Rollback scripts

Usage Example

skill:
  name: codemod-generator
  context:
    sourceVersion: "1.x"
    targetVersion: "2.0"
    languages:
      - typescript
      - python
    transformations:
      - type: methodRename
        from: oldMethod
        to: newMethod
      - type: parameterChange
        method: createResource
        changes:
          - name: config
            wrap: options
    dryRun: true
    generateTests: true

Best Practices

1. Always provide dry-run mode first
2. Generate comprehensive change reports
3. Handle partial migrations gracefully
4. Include rollback capabilities
5. Test codemods against real codebases
6. Document manual intervention cases