Strategy for Converting Express Directory Files to TypeScript

Overview

This document outlines the strategy for converting the JavaScript files in the express directory to TypeScript. The conversion will be done in phases, starting with the most fundamental modules and working up to the more complex ones.

Conversion Order

1. Constants and Utilities

   • Start with constants.js and utility files in the utils directory
   • These are typically simpler and have fewer dependencies
   • They provide the foundation for other modules

2. Services

   • Convert service files in the services directory
   • These typically depend on utilities but are used by controllers
   • Focus on one service at a time, starting with simpler ones

3. Persistence

   • Convert persistence files that handle data storage
   • These are used by services and may have complex interactions

4. Controllers

   • Convert controller files in the controllers directory
   • These depend on services and utilities
   • They handle HTTP requests and responses

5. Routes and Container

   • Convert routes.js and container.js
   • These tie everything together and should be converted last
   • They depend on all other modules being converted

Conversion Process for Each File

1. Create a TypeScript version of the file with the same name but .ts extension
2. Convert require() statements to import statements
3. Add type annotations for:
   • Function parameters
   • Return values
   • Class properties
   • Variables
4. Handle any special TypeScript considerations (interfaces, generics, etc.)
5. Test the converted file to ensure it works correctly

Type Definitions

• Create type definitions for third-party modules as needed
• Define interfaces for common data structures
• Use existing type definitions from DefinitelyTyped when available

Testing

• After converting each file, run the relevant tests
• After converting a group of related files, run all tests
• Ensure the application still works correctly after each conversion

Special Considerations

• Some files may have circular dependencies that need to be addressed
• Some files may use dynamic imports or other patterns that require special handling in TypeScript
• Some files may use JavaScript features that don't translate directly to TypeScript

Rollback Plan

• Keep the original JavaScript files until the conversion is complete and tested
• If issues arise, revert to the JavaScript version until the issues are resolved