Migrate to TypeScript

Migrate JavaScript project to TypeScript

Instructions

1. Project Analysis and Migration Planning

   • Analyze current JavaScript codebase structure and complexity
   • Identify external dependencies and their TypeScript support
   • Assess project size and determine migration approach (gradual vs. complete)
   • Review existing build system and bundling configuration
   • Create migration timeline and phased approach plan

2. TypeScript Installation and Configuration

   • Install TypeScript and related dependencies (@types packages)
   • Create comprehensive tsconfig.json with strict configuration
   • Configure path mapping and module resolution
   • Set up incremental compilation and build optimization
   • Configure TypeScript for different environments (development, production, testing)

3. Build System Integration

   • Update build tools to support TypeScript compilation
   • Configure webpack, Vite, or other bundlers for TypeScript
   • Set up development server with TypeScript support
   • Configure hot module replacement for TypeScript files
   • Update build scripts and package.json configurations

4. File Migration Strategy

   • Start with configuration files and utility modules
   • Migrate from least to most complex modules
   • Rename .js files to .ts/.tsx incrementally
   • Update import/export statements to use TypeScript syntax
   • Handle mixed JavaScript/TypeScript codebase during transition

5. Type Definitions and Interfaces

   • Create comprehensive type definitions for project-specific types
   • Install @types packages for external dependencies
   • Define interfaces for API responses and data structures
   • Create custom type declarations for untyped libraries
   • Set up shared types and interfaces across modules

6. Code Transformation and Type Annotation

   • Add explicit type annotations to function parameters and return types
   • Convert JavaScript classes to TypeScript with proper typing
   • Transform object literals to typed interfaces
   • Add generic types for reusable components and functions
   • Handle complex types like union types, mapped types, and conditional types

7. Error Resolution and Type Safety

   • Resolve TypeScript compiler errors systematically
   • Fix type mismatches and undefined behavior
   • Handle null and undefined values with strict null checks
   • Configure ESLint rules for TypeScript best practices
   • Set up type checking in CI/CD pipeline

8. Testing and Validation

   • Update test files to TypeScript
   • Configure testing framework for TypeScript support
   • Add type testing with tools like tsd or @typescript-eslint
   • Validate type safety in test suites
   • Set up type coverage reporting

9. Developer Experience Enhancement

   • Configure IDE/editor for optimal TypeScript support
   • Set up IntelliSense and auto-completion
   • Configure debugging for TypeScript source maps
   • Set up type-aware linting and formatting
   • Create TypeScript-specific code snippets and templates

10. Documentation and Team Onboarding

    • Update project documentation for TypeScript setup
    • Create TypeScript coding standards and best practices guide
    • Document migration decisions and type system architecture
    • Set up type documentation generation
    • Train team members on TypeScript development workflows
    • Create troubleshooting guide for common TypeScript issues