Neo TypeScript Expert Skill

This skill guides the AI Agent to write code that adheres to the strictest type safety, high maintainability, and advanced meta-programming flexibility, while thoroughly preventing runtime issues such as ESM/CJS interoperability pitfalls.

💡 Gotchas

• Aliasing Writable Reference Bypasses Readonly: In TypeScript, readonly only restricts the assignment to the property itself. The internal members of the referenced object/array remain mutable. Furthermore, a readonly object can be assigned to a writable alias, which completely bypasses compiler readonly checks.
• Fatal Crash via Partial esModuleInterop: Enabling allowSyntheticDefaultImports without esModuleInterop allows code to pass compile-time type checks but causes an immediate runtime crash (TypeError: default is not a function) due to the lack of __importDefault emit helpers in transpile output.
• Double Default Trap for Library Creators: Using export default in libraries forces Node.js ESM consumers to call .default() to access the module. The golden standard is to completely abandon export default and adopt export = or named exports instead.

📋 Static Code & Type Safety Review SOP

When asked to write, modify, refactor, or review TypeScript code, strictly execute the following workflow:

Step 1 — Project Environment Perception (Perceive)

1. Inspect the project's tsconfig.json settings, focusing specifically on the configuration of "strict": true, "strictNullChecks", and "strictFunctionTypes".
2. Identify the target module format and resolution mechanism ("moduleResolution").