JavaScript ES modules (.mjs) with KISS, modern OOP, and ESM conventions. Use when writing or editing .mjs files, ES module import/export code, or Node.js scripts with ES module syntax.
Installation
Install with Codex or Claude Copy this prompt, paste it into Codex, Claude, or another assistant, and let it review the skill page and install it for you.
JavaScript ES modules (.mjs) with KISS, modern OOP, and ESM conventions. Use when writing or editing .mjs files, ES module import/export code, or Node.js scripts with ES module syntax.
Javascript Mjs
Keep It Simple (KISS)
Do NOT overengineer. Simple functions > complex class hierarchies.
One file = one responsibility. If a file exceeds 200 lines, split it.
Avoid unnecessary abstractions (no factories for a single implementation).
Prefer plain objects and functions over classes when state is simple.
OOP When Appropriate
Preferre classes over function based huge single scripts. Instantiate a root controller which will then instantiate and manage all other classes (eg /includes/js/Main.mjs, /includes/js/NavHandler.mjs). Main.mjs should be a singleton.
Anything that is re-usable that could be classed as a utility place in a utils dir in the /includes/js/utils folder
Single responsibility per class - a class should do ONE thing well.
Favor composition over inheritance - pass dependencies in, don't extend.
Private fields: use #privateField syntax, not _convention.
Code Conventions
Use const by default, let when reassignment is needed. Never var.
Arrow functions for callbacks, named functions for top-level logic.
async/await over raw promises. Always handle rejections.
Destructure parameters: function({name, age}) over function(obj).
Use template literals (backticks) for string building.
Module Rules
One export default per module for the main export.
Named exports for utilities and helpers.
Import order: node built-ins โ npm packages โ local modules.
No side effects at import time - exports should be pure.
