Consistent with type definition either interface or type (consistent-type-definitions)

There are two ways to define a type.

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

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

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"]
}

Rule Details

Examples of incorrect code with interface option.

type T = { x: number };

Examples of correct code with interface option.

type T = string;
type Foo = string | {};

interface T {
  x: number;
}

Examples of incorrect code with type option.

interface T {
  x: number;
}

Examples of correct code with type option.

type 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.

Compatibility