Generic Fetch Wrapper

interface ApiError {
  message: string;
  status: number;
}

async function fetchJson<T>(url: string, options?: RequestInit): Promise<T> {
  const response = await fetch(url, {
    headers: { 'Content-Type': 'application/json' },
    ...options,
  });

  if (!response.ok) {
    const error: ApiError = {
      message: response.statusText,
      status: response.status,
    };
    throw error;
  }

  return response.json() as Promise<T>;
}

// HTTP methods
const api = {
  get: <T>(url: string) => fetchJson<T>(url),

  post: <T, B>(url: string, body: B) =>
    fetchJson<T>(url, {
      method: 'POST',
      body: JSON.stringify(body),
    }),

  put: <T, B>(url: string, body: B) =>
    fetchJson<T>(url, {
      method: 'PUT',
      body: JSON.stringify(body),
    }),

  delete: <T>(url: string) => fetchJson<T>(url, { method: 'DELETE' }),
};

interface User {
  id: number;
  name: string;
}

const user = await api.get<User>('/api/users/1');
const newUser = await api.post<User, Omit<User, 'id'>>('/api/users', {
  name: 'John',
});