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 "record" to only allow the Record type. Set to "index-signature" to only allow index signatures. (Defaults to "record")

For example:

{
    "@typescript-eslint/consistent-type-definitions": ["error", "index-signature"]
}

Rule details

This rule enforces a consistent way to define records.

Examples of incorrect code with record option.

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

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

Examples of correct code with record option.

type Foo = Record<string, unknown>;

Examples of incorrect code with index-signature option.

type Foo = Record<string, unknown>;

Examples of correct code with index-signature option.

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

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