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consistent-type-definitions

Enforces type definitions to consistently use either interface or type.

There are two ways to define a type.

// type alias
type T1 = {
  a: string;
  b: number;
};

// interface keyword
interface T2 {
  a: string;
  b: number;
}

Attributes​

  • Included in configs
    • ✅ Recommended
    • 🔒 Strict
  • Fixable
    • 🔧 Automated Fixer
    • 🛠 Suggestion Fixer
  • 💭 Requires type information

Options​

This rule accepts one string option:

  • "interface": enforce using interfaces for object type definitions.
  • "type": enforce using types for object type definitions.

For example:

{
  // Use type for object definitions
  "@typescript-eslint/consistent-type-definitions": ["error", "type"]
}

interface​

Examples of code with interface option.

type T = { x: number };

type​

Examples of code with type option.

interface T {
  x: number;
}

When Not To Use It​

If you specifically want to use an interface or type literal for stylistic reasons, you can disable this rule.