Cannot set headers after they are sent to the client #8
Description
I keep getting the error
Cannot set headers after they are sent to the clientError [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
at send (node_modules/micro/lib/index.js:76:6)
at sendError (node_modules/micro/lib/index.js:83:2)
at node_modules/micro/lib/index.js:110:17I'm testing with Jest and my serverless function (which works in production) is something like this (I whittled it down to what you are seeing in the code and I still got the error)
import { VercelRequest, VercelResponse } from "@vercel/node";
module.exports = async (req: VercelRequest, res: VercelResponse) => {
res.status(200).send("hello")
}Here is how my test file looks
import * as request from "request";
import { createServer } from "vercel-node-server";
import listen from "test-listen";
import { promisify } from "util";
const lambdaFn = require("./path-to-lamda-fn");
const get = promisify(request.get);
let server: any;
let url: string;
describe("name of test", () => {
// beforeAll(async () => {
// server = createServer(twitterWebhookLambda);
// url = await listen(server)
// console.log("url:", url);
// });
// afterAll(() => {
// server.close();
// });
it("should return the expected response", async () => {
const server = createServer(lambdaFn)
server.listen(8000)
const res = await get({url: "http://localhost:8000"})
expect (res.statusCode).toBe(200)
server.close()
});
});OS: Ubuntu 20
Node version: 14.x
Yarn version: 1.22.x
"vercel": "^22.0.1"
I also tried it with Axios and I got the same error
Nice work here!