transform-entity.ts

// library

type TransformFunction = (rawResponse: object) => object;
type TransformedEntity<T extends TransformFunction> = ReturnType<T
>;

// indivisual

function transform1(rawResponse: object) {
  return {
    keyName1: rawResponse['0'],
    keyName2: rawResponse['1'],
  };
}

type Entity1 = TransformedEntity<typeof transform1>;

const entity1: Entity1 = {
  a: 'aaa' // type error
}