JavaScript Code Doctrine

JavaScript must be treated as a strict, production-ready language. We avoid historical JS quirks and default to modern, deterministic, and safe patterns.

The Iron Law

No silent failures, no implicit globals, no parameter mutation.

Core Principles

1. Modern Context (ESM & strict): Always use ES Modules (import/export). Always operate in strict mode (inherent in ESM).
2. Immutability First: Never mutate function parameters. Treat all inputs as read-only. Prefer const over let. Never use var. Use array/object spread operators to create new references instead of mutating existing ones.
3. Pure Functions: Functions should be deterministic. If a function requires external state, inject it as a dependency.
4. Predictable Types (Runtime): Even without TS, ensure objects are structured consistently. Avoid dynamically adding/removing object keys if possible.

Functional & Structural Rules