consistent-indexed-object-style.md

Enforce or disallow the use of the record type (consistent-indexed-object-style)

TypeScript supports defining object show keys can be flexible using an index signature. TypeScript also has a builtin type named Record to create an empty object defining only an index signature. For example, the following types are equal:

interface Foo {
  [key: string]: unknown;
}

type Foo = {
  [key: string]: unknown;
};

type Foo = Record<string, unknown>;

Options

• "record": Set to "always" to only allow the Record type. Set to "never" to only allow index signatures. (Defaults to "always")

For example:

{
    "@typescript-eslint/consistent-type-definitions": ["error", "never"]
}

Rule details

This rule enforces a consistent way to define records.

Examples of incorrect code with always option.

interface Foo {
  [key: string]: unknown;
}

type Foo = {
  [key: string]: unknown;
};

Examples of correct code with always option.

type Foo = Record<string, unknown>;

Examples of incorrect code with never option.

type Foo = Record<string, unknown>;

Examples of correct code with never option.

interface Foo {
  [key: string]: unknown;
}

type Foo = {
  [key: string]: unknown;
};