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🧠 Cursor Rule — Document Code with TSDoc for Runtime Alignment

Official
CursorArchitecture & Best Practices
cursordocumentationtsdoctypescript

Goal

Enable clear intent, safer refactors, and accurate AI assistance by documenting real function behavior using TSDoc validated through execution.

Rule Behavior

1️⃣ Document Intent to Guide Runtime Expectations

  • Describe what the function achieves and why it exists
  • Include expected side effects and responsibilities

2️⃣ Specify Input Meaning and Boundaries

  • Define parameter purpose and constraints
  • Mark nullable, optional, or restricted values

3️⃣ Define Output Shape and Error Behavior

  • Provide return type expectations and failure conditions
  • Help Agent validate runtime safety of edge cases

4️⃣ Keep Docs Synced With Execution Logs

  • Update TSDoc when code behavior or shape changes
  • Use runtime feedback to detect outdated documentation

5️⃣ Prioritize High Usage Modules First

  • Document shared utilities and domain models early
  • Enable AI refactors without introducing misunderstandings

Examples

  • "Add TSDoc describing intent and return type for this pricing utility."
  • "Document error cases for this async fetch function."

Tool Prompts

  • "Generate TSDoc for all exported functions with intent summaries."
  • "Check for mismatches between TSDoc types and runtime values."
  • "Extract interface from executed output and update TSDoc accordingly."

Quick Implementation Wins

  • Add TSDoc to modules involved in user facing flows
  • Include error notes for async behaviors
  • Use documentation to drive better test case generation
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