enumInitializers

Reports enum members without explicit initial values.

✅ This rule is included in the ts logical and logicalStrict presets.

TypeScript enums assign sequentially increasing numbers to members that don’t have explicit values. This behavior can cause unintended value changes if enum members are reordered, added, or removed. Explicitly initializing each enum member prevents these issues and makes the code’s intent clearer.

Examples

❌ Incorrect

enum Status {
  Pending,
  Active,
  Completed,
}

enum Direction {
  Up,
  Down,
}

✅ Correct

enum Status {
  Pending = 0,
  Active = 1,
  Completed = 2,
}

enum Direction {
  Up = "Up",
  Down = "Down",
}

Options

This rule is not configurable.

When Not To Use It

If the numeric values of enum members are not important to your project, you may not need this rule. This can be the case when enums are only used for type safety and the actual runtime values are never inspected or stored externally.

Further Reading

• TypeScript handbook: Enums
• MDN: Enumerations

Equivalents in Other Linters

• Biome: useEnumInitializers
• ESLint: @typescript-eslint/prefer-enum-initializers
• Oxlint: typescript/prefer-enum-initializers