prefer-module-scope-constants

Require SCREAMING_SNAKE_CASE variables to be const declarations at module scope.

Rule details Suggestion

This rule checks simple identifier names that match SCREAMING_SNAKE_CASE. Those bindings must use const, and they must live at the top level of the module.

If a value needs to change, or it only makes sense inside a function or block, use a different name.

What it ignores

Destructuring is not checked by this rule. const {FOO} = config and const [FOO] = values are both allowed.

Examples

Incorrect

Local or mutable uppercase names

function calculate() {
  const PI = 3.14;
}

let MAX_RETRIES = 3;

Correct

Module-scope constants

const PI = 3.14;
const MAX_RETRIES = 3;

function calculate(radius: number) {
  return radius * radius * PI;
}

Notes

In script files, the rule also allows a first-level function scope. That matches common CommonJS wrapper patterns.

Related rules

prefer-pascal-case-enums Keeps enum names and members in PascalCase