Software Style Guide

Converse uses Prettier to enforce a consistent code style across the codebase. The configuration lives in .prettierrc at the project root.

Run Prettier on your changes before committing:

npx prettier --write src/path/to/file.js

Many of the conventions below are enforced by Prettier automatically. Where Prettier doesn’t cover something (naming conventions, architectural patterns), the rules below apply.

Prettier configuration

Our Prettier settings:

Setting	Value
tabWidth	4 spaces
useTabs	false (spaces, not tabs)
singleQuote	true
printWidth	120
spaceBeforeFunctionParen	true
bracketSpacing	true

Naming conventions

Variables and functions

We use snake_case for variable names and camelCase for function names.

function thisIsAFunction () {
    let this_is_a_variable;
    ...
}

Classes

Use PascalCase for class names.

Constants

Global identifiers that denote constant values should be written in UPPER_CASE, with underscores between words.

const SECONDS_IN_HOUR = 3600;

function update () {
    const timeout = 20;
    let seconds_since_message = 0;
}

const versus let

Try to use const whenever possible. If a variable won’t be reassigned, use const, otherwise use let.

Checking for equality

JavaScript has a strict === and less strict == equality operator. The stricter equality operator also does type checking. To avoid subtle bugs when doing comparisons, always use the strict equality check.

Always enclose blocks in curly brackets

When writing a block such as an if or while statement, always use curly brackets around that block of code. Even when not strictly required by the compiler (for example if its only one line inside the if statement).

if (condition === true) {
    this.updateRoomsList();
}
somethingElse();

and NOT like this:

if (converse.auto_list_rooms)
    this.updateRoomsList();
somethingElse();

This is to aid in readability and to avoid subtle bugs where certain lines are wrongly assumed to be executed within a block.