id-match

Use this rule to hold a project to one naming convention, for example no underscores or only camelCase. You give it a regular expression, and it reports the names that don't match.

The default pattern, ^.+$, matches every name, so the rule reports nothing until you set one.

Configure

Off by default. To turn it on:

[lint.rules]
"id-match" = "error" # or "warn"

Every option, set to its default:

[lint.rules]
"id-match" = ["error", "^.+$", {
  properties = false,
  classFields = false,
  onlyDeclarations = false,
  ignoreDestructuring = false,
}]

Examples

[lint.rules]
id-match = ["error", "^[^_]+$"]

The examples on this page use ^[^_]+$, which means no underscores.

Reported:

const user_name = "Ada";

function load_user(user_id) {}

Not reported:

const userName = "Ada";

function loadUser(userId) {}

A function you call and a property you read may come from code you don't control, so they aren't checked:

const total = get_total(order.line_items);

Options

The first option is the pattern. The second is an object:

Option	Default	What it does
properties	false	Also check object literal keys and the properties you assign to.
classFields	false	Also check class fields. Methods are checked either way.
onlyDeclarations	false	Only check a name where it's declared, not where it's used.
ignoreDestructuring	false	Don't check a destructured variable that keeps the property's name.

properties

const user = { first_name: "Ada" };
user.last_name = "Lovelace";

const user = { first_name: "Ada" };
user.last_name = "Lovelace";

classFields

class User {
  first_name = "Ada";
  full_name() {}
}

class User {
  first_name = "Ada";
  full_name() {}
}

onlyDeclarations

if (legacy_mode) {
  start();
}

if (legacy_mode) {
  start();
}

const legacy_mode = true;

ignoreDestructuring

const { user_id } = row;

const { user_id } = row;

A new name that you choose is still checked:

const { user_id: owner_id } = row;