name: programming description: Always use this skill when writing or editing code of any sort!

programming

• Avoid adding comments to code; they usually clutter the code and get stale easily.
  • Only use them to explain difficult to read behavior and other out-of-band info.
  • Actively remove stale comments and docstrings that don't add value.
  • Use intention-revealing names instead and maintain a consistent vocabulary across the codebase.
• Functions
  • Prefer stateless/pure functions, as they're easier to test and reason about.
  • Separate I/O operations from business logic (Functional Core, Imperative Shell pattern).
    • Googleblog source
    • Extract decision logic into pure functions.
    • Keep side effects (database calls, API requests, file I/O) in the outer shell layer.
    • This makes core logic testable without mocking and reusable across features.
  • Aim for one level of abstraction per function.
  • Try to keep them short.
  • If a function needs many arguments, consider using an object or splitting it into multiple functions.
• Run code that you write unless explicitly told not to.
  • It is imperative that you verify the code you write works as intended.
• Avoid mutable global state; it leads to unintended side effects.
• Prefer reusing and extending things.
  • e.g.: if fixtures exist, use them or generalize them.
  • But beware: existing code might be broken; build on top of it, but always test it.
• Avoid unnecessary breaklines in the code; they make the file needlessly longer.
  • Keep related code vertically dense.
    • Declare variables close to usage.
    • Place functions that are dependent on one another close together to make it easier to follow the flow of logic.
      • Place functions in a downward direction, with higher-level functions appearing before lower-level ones.
• When writing validation logic, prefer early returns on errors.