coder / coder/websocket

all goroutines are dead asleep - deadlock! wasm docs

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Description

I'm trying to do the next:
### Client Code:
```go
//go:build js && wasm

package main

import (
"context"
"log"
"syscall/js"

"nhooyr.io/websocket"
)

func main() {
ctx := context.Background()
window := js.Global()
window.Set("goWS", js.FuncOf(func(_ js.Value, args []js.Value) any {
conn, _, err := websocket.Dial(ctx, args[0].String(), nil)
if err != nil {
log.Fatal(err)
}
goWSObject := window.Get("goWS")
goWSObject.Set("send", js.FuncOf(func(_ js.Value, args []js.Value) any {
if err := conn.Write(ctx, websocket.MessageText, []byte(args[0].String())); err != nil {
log.Fatal(err)
}
return nil
}))
goWSObject.Set("waitMessage", js.FuncOf(func(_ js.Value, _ []js.Value) any {
_, bb, err := conn.Read(ctx)
if err != nil {
log.Fatal(err)
}
return bb
}))
return nil
}))
waitCh := make(chan struct{})
<-waitCh
}
```
### `index.html`:
```html



goWS


const go = new Go();
WebAssembly.instantiateStreaming(fetch("/assets/app.wasm"), go.importObject)
.then(res => go.run(res.instance))

```
### Server code:
```go
package main

import (
"context"
"net/http"

"nhooyr.io/websocket"
)

func main() {
ctx := context.Background()

http.HandleFunc("/ws-chat", func(w http.ResponseWriter, r *http.Request) {
conn, err := websocket.Accept(w, r, &websocket.AcceptOptions{
InsecureSkipVerify: true,
})
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
_, bb, err := conn.Read(ctx)
if err != nil {
conn.Close(websocket.StatusInternalError, err.Error())
return
}
wr, err := conn.Writer(ctx, websocket.MessageText)
if err != nil {
conn.Close(websocket.StatusInternalError, err.Error())
return
}
wr.Write(bb)
wr.Close()
conn.CloseNow()
})
http.ListenAndServe(":8080", http.DefaultServeMux)
}
```
Also I'm going to attach my Makefile so you can see the commands when I'm compiling:
```make
build_client:
GOOS=js GOARCH=wasm go build -o dist/assets/app.wasm cmd/go-ws-client/main.go
cp $(go env GOROOT)/misc/wasm/wasm_exec.js dist/assets/

build_server:
go build -o dist/bin/app-server cmd/go-ws-server/main.go
```
### Structure of `dist` folder:
```
dist/
- assets/
- app.wasm
- wasm_exec.js
- bin/
- app-server
- index.html
```
But i'm getting the following errors after calling `window.goWS("ws://localhost:8080/ws-chat")` from the firefox browser's console:
### Console:
```
> window.goWS("ws://localhost:8080/ws-chat")
fatal error: all goroutines are asleep - deadlock! wasm_exec.js:22:14

wasm_exec.js:22:14
goroutine 1 [chan receive]: wasm_exec.js:22:14
main.main() wasm_exec.js:22:14
/home/oscar/Escritorio/proyecto-react/cmd/go-ws-client/main.go:47 +0xc wasm_exec.js:22:14
wasm_exec.js:22:14
goroutine 7 [select]: wasm_exec.js:22:14
nhooyr.io/websocket.dial({0x5aa80, 0x1430050}, {0x1466020, 0x1b}, 0x0) wasm_exec.js:22:14
/home/oscar/go/pkg/mod/nhooyr.io/websocket@v1.8.10/ws_js.go:320 +0x1c wasm_exec.js:22:14
nhooyr.io/websocket.Dial({0x5aa80, 0x1430050}, {0x1466020, 0x1b}, 0x0) wasm_exec.js:22:14
/home/oscar/go/pkg/mod/nhooyr.io/websocket@v1.8.10/ws_js.go:289 +0x2 wasm_exec.js:22:14
main.main.func1.1({{}, 0x0, 0x0}, {0x140e0f0, 0x1, 0x1}) wasm_exec.js:22:14
/home/oscar/Escritorio/proyecto-react/cmd/go-ws-client/main.go:19 +0x4 wasm_exec.js:22:14
syscall/js.handleEvent() wasm_exec.js:22:14
/usr/local/go/src/syscall/js/func.go:100 +0x26 wasm_exec.js:22:14
exit code: 2 wasm_exec.js:101:14
undefined
```

Contributor guide

No contributing guide indexed for this repository

Research direction

Start with cmd/go-ws-client/main.go and reproduce the window.goWS("ws://localhost:8080/ws-chat") call using the provided index.html and Makefile commands. Then inspect ws_js.go around the reported Dial stack frame and compare the WebAssembly behavior with the server example. Done means the deadlock is explained and the issue's documented usage or reproduction is corrected and verified.

Written by the indexing model from the issue text.

Assessment

Tech stack
go, wasm
Domain
networking
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
30/100

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