fix: support new vercel style

util/http.ts

@@ -0,0 +1,28 @@
+import nodeFetch, {Response} from 'node-fetch';
+import {NowResponse} from '@vercel/node';
+
+export type HttpMethod =
+  | 'GET'
+  | 'POST'
+  | 'PUT'
+  | 'DELETE'
+  | 'HEAD'
+  | 'PATCH'
+  | 'CONNECT'
+  | 'TRACE';
+
+export function fetch(
+  url: string,
+  method: HttpMethod = 'HEAD',
+): Promise<Response> {
+  return nodeFetch(url, {method: method});
+}
+
+export function send(res: NowResponse, data: object): void {
+  res.setHeader('Cache-Control', 's-maxage=86400');
+  res.json(data);
+}
+
+export function sendError(res: NowResponse, error: Error): void {
+  res.status(400).json({error: error.message});
+}

util/testHelpers.ts

@@ -0,0 +1,16 @@
+export async function mockProvider(
+  provider: any,
+  query: unknown,
+): Promise<string> {
+  const req = {
+    query,
+  };
+  const res = {
+    status: jest.fn().mockReturnThis(),
+    send: jest.fn().mockReturnThis(),
+    json: jest.fn().mockReturnThis(),
+    setHeader: jest.fn(),
+  };
+  await provider(req, res);
+  return res.json.mock.calls[0][0];
+}