service.js

const host = 'https://api.github.com/';

const request = {
  const req = (path, method, opts, params) => {
    return fetch(`${host}/v3/${path}?${params}`, {
      headers,
      method,
      ...opts
    });
  };

  return {
    get: (path, params, opt) => req(path, 'GET', opt, params),
    del: path => req(path, 'DELETE'),
    post: (path, data) => req(path, 'POST', {
      body: JSON.stringify(data),
    }),
    put: (path, data) => req(path, 'PUT', {
      body: JSON.stringify(data),
    }),
  };
}

request.get('users');