Allow TypeScript to infer types

const isUserEditor = (user: User): boolean => {
  return user.role === 'editor';
};

const isUserEditor = (user: User) => {
  return user.role === 'editor';
};

You do not need to explicitly define all the return types of functions. Instead, you can allow TypeScript to infer the types for you. This reduces the amount of code you need to write, and makes your code easier to read.