Pureline JavaScript

Braces Are Mandatory

Every control-flow body gets a block, even for a single statement.

if (!user) return;

while (queue.length) process(queue.shift());

if (!user) {
    return;
}

Use Semicolons

Pureline JavaScript uses semicolons consistently and does not rely on automatic semicolon insertion.

const session = createSession(user)
session.start()

const total = base + tax
[fee, tip].forEach(add)

const session = createSession(user);
session.start();

`const` First

const is the default. Use let only for actual reassignment. Do not use var.

var user = loadUser();

let session = createSession(user);
session.start();

const user = loadUser();

let count = 0;
count++;

Prefer `async` / `await`

Avoid promise chains when async/await produces clearer control flow.

function loadUser(id) {
    return fetch(`/users/${id}`)
        .then(response => response.ok ? response.json() : null);
}

async function loadUser(id) {
    const response = await fetch(`/users/${id}`);

    if (!response.ok) {
        return null;
    }

    return response.json();
}

Arrow Functions Are Contextual

Normal named logic may use regular functions. Arrow functions are well suited for local callbacks, but are not the default for everything.

const createSession = (user) => {
    const session = new Session(user);
    session.start();
    return session;
};

function createSession(user) {
    return new Session(user);
}

users.filter(user => user.active());

Destructuring Must Improve Clarity

Destructuring is good when it shows intent. Large objects are not destructured merely because the language allows it.

const { id, name, email, role, createdAt, updatedAt, settings: { theme, locale } } = user;

const { id, name } = user;

Folder Density

A JavaScript feature/source folder may contain at most **10 production source modules** by default.

Barrel files such as index.js, tests, generated files, and metadata-only files do not count.

If the folder exceeds the limit, split it by responsibility rather than by arbitrary file count.

session/
    index.js
    state/
    transport/
    storage/