camelcase

Enforces the use of camelCase in variable names.

Consistency in a code base is key for readability and maintainability. This rule enforces variable declarations and object property names which you create to be in camelCase.

Of note:

_ is allowed at the start or end of a variable
All uppercase variable names (e.g. constants) may have _ in their name
If you have to use a snake_case key in an object for some reasons, wrap it in quotation mark
This rule also applies to variables imported or exported via ES modules, but not to object properties of those variables

Invalid:

let first_name = "Ichigo";
const obj1 = { last_name: "Hoshimiya" };
const obj2 = { first_name };
const { last_name } = obj1;

function do_something() {}
function foo({ snake_case = "default value" }) {}

class snake_case_class {}
class Also_Not_Valid_Class {}

import { not_camelCased } from "external-module.js";
export * as not_camelCased from "mod.ts";

enum snake_case_enum {
  snake_case_variant,
}

type snake_case_type = { some_property: number };

interface snake_case_interface {
  some_property: number;
}

Valid:

let firstName = "Ichigo";
const FIRST_NAME = "Ichigo";
const __myPrivateVariable = "Hoshimiya";
const myPrivateVariable_ = "Hoshimiya";
const obj1 = { "last_name": "Hoshimiya" }; // if an object key is wrapped in quotation mark, then it's valid
const obj2 = { "first_name": first_name };
const { last_name: lastName } = obj;

function doSomething() {} // function declarations must be camelCase but...
do_something(); // ...snake_case function calls are allowed
function foo({ snake_case: camelCase = "default value" }) {}

class PascalCaseClass {}

import { not_camelCased as camelCased } from "external-module.js";
export * as camelCased from "mod.ts";

enum PascalCaseEnum {
  PascalCaseVariant,
}

type PascalCaseType = { someProperty: number };

interface PascalCaseInterface {
  someProperty: number;
}

camelcase

Did you find what you needed?