#prefer-enum-initializers

#Configuration

import { defineConfig, ts } from '@rslint/core';

export default defineConfig([
  ts.configs.recommended,
  {
    rules: {
      '@typescript-eslint/prefer-enum-initializers': 'error',
    },
  },
]);

#Rule Details

Require each enum member to have an explicitly initialized value.

TypeScript enum members default to a sequential numeric value when no initializer is provided. Relying on that implicit numbering makes the enum fragile — inserting, deleting, or reordering members silently shifts the numeric value of every later member, which can break code that persisted those numbers (in storage, in a network protocol, in serialized output). Explicit initializers make the value of each member a documented, stable choice. For each uninitialized member, this rule reports a diagnostic and offers three suggestions: initialize to the member's current index, to the index plus one, or to a string matching the member's name.

Examples of incorrect code for this rule:

enum Direction {
  Up,
  Down,
}

enum Status {
  Open = 1,
  Close,
}

Examples of correct code for this rule:

enum Direction {
  Up = 1,
  Down = 2,
}

enum Status {
  Open = 'Open',
  Close = 'Close',
}

enum Empty {}

#Original Documentation

• typescript-eslint prefer-enum-initializers