limit-function-arguments

Summary

Functions should ideally have 0 to 2 arguments, and at most 3. If a function requires more than 3 arguments, group them into a single Object, Interface, or Struct (often called "Options Object" or "Named Parameters").

Rationale

• Readability: A call like createUser(name, true, false, 5) is ambiguous. createUser({ name, isAdmin: true, ... }) is self-documenting.
• Order Safety: Positional arguments are prone to off-by-one errors or swapped values (e.g., width vs height).
• Extensibility: Adding a new field to an options object does not break the function signature for existing callers.

Guidance

1. Count Rule:
   • 0-2 args: Great.
   • 3 args: Acceptable.
   • 4+ args: Refactor to use an Object/Struct.
2. Grouping:
   • Identify related arguments and group them (e.g., x, y, z -> Vector3).
3. Language Specifics:
   • TS/JS: Use destructuring in the signature. function foo({ a, b }: Options).
   • Go: Use a Config struct. func NewServer(cfg Config).