namae/api/services/gitlab/[query].ts

import { send, sendError } from '../../../util/http';
import { NowRequest, NowResponse } from '@vercel/node';
import nodeFetch from 'isomorphic-unfetch';

export default async function handler(
  req: NowRequest,
  res: NowResponse
): Promise<void> {
  const { query } = req.query;

  if (!query || typeof query !== 'string') {
    return sendError(res, new Error('No query given'));
  }

  if (/[^a-zA-Z0-9_-]/.test(query)) {
    return sendError(res, new Error('Invalid characters'));
  }

  try {
    const response = await nodeFetch(`https://gitlab.com/${query}`, {
      redirect: 'manual',
    });
    const availability = response.status === 302;
    send(res, { availability });
  } catch (err) {
    sendError(res, err);
  }
}