Deno Types

What is the Deno.ServeHandler type?

No overload matches this call.
  Overload 1 of 3, '(handler: ServeHandler): Server', gave the following error.
    Argument of type '(request: Request) => Promise<Response | undefined>' is not assignable to parameter of type 'ServeHandler'.
      Type 'Promise<Response | undefined>' is not assignable to type 'Response | Promise<Response>'.
        Type 'Promise<Response | undefined>' is not assignable to type 'Promise<Response>'.
          Type 'Response | undefined' is not assignable to type 'Response'.
            Type 'undefined' is not assignable to type 'Response'.  Overload 2 of 3, '(options: ServeInit & (ServeOptions | ServeTlsOptions)): Server', gave the following error.

No overload matches this call.
  Overload 1 of 3, '(handler: ServeHandler): Server', gave the following error.
    Argument of type '(request: Request) => Promise<Response | undefined>' is not assignable to parameter of type 'ServeHandler'.
      Type 'Promise<Response | undefined>' is not assignable to type 'Response | Promise<Response>'.
        Type 'Promise<Response | undefined>' is not assignable to type 'Promise<Response>'.
          Type 'Response | undefined' is not assignable to type 'Response'.
            Type 'undefined' is not assignable to type 'Response'.  Overload 2 of 3, '(options: ServeInit & (ServeOptions | ServeTlsOptions)): Server', gave the following error.

Does it not support async?

9 Replies

ioB•12mo ago

It does support async, how are you trying to call Deno.serve?

mostprodev•12mo ago

Deno.serve(async (request) => {
"stuff"
});

Deno.serve(async (request) => {
"stuff"
});

ioB•12mo ago

You're not returning a response, the type error is concerned with that.

mostprodev•12mo ago

Makes sense. What about

error: Uncaught AddrInUse: Address already in use (os error 48)
  Deno.serve(async (request) => {

error: Uncaught AddrInUse: Address already in use (os error 48)
  Deno.serve(async (request) => {

? Is there a way to set another port?

ioB•12mo ago

another server is running on port 8000

mostprodev•12mo ago

Yes.

ioB•12mo ago

Yes, add the port as an argument:

Deno.serve({ port: 1000 },()=>{
  return new Response("hi")
})

Deno.serve({ port: 1000 },()=>{
  return new Response("hi")
})

mostprodev•12mo ago

Okay, thanks!

shawnbu•12mo ago

I get that also. Just need to return a new Response()