[client,signal,management] Add browser client support (#4415)

shared/relay/client/dialer/ws/conn.go

@@ -38,8 +38,7 @@ func (c *Conn) Read(b []byte) (n int, err error) {
 }
 
 func (c *Conn) Write(b []byte) (n int, err error) {
-	err = c.Conn.Write(c.ctx, websocket.MessageBinary, b)
-	return 0, err
+	return 0, c.Conn.Write(c.ctx, websocket.MessageBinary, b)
 }
 
 func (c *Conn) RemoteAddr() net.Addr {

shared/relay/client/dialer/ws/dialopts_generic.go

@@ -0,0 +1,11 @@
+//go:build !js
+
+package ws
+
+import "github.com/coder/websocket"
+
+func createDialOptions() *websocket.DialOptions {
+	return &websocket.DialOptions{
+		HTTPClient: httpClientNbDialer(),
+	}
+}

shared/relay/client/dialer/ws/dialopts_js.go

@@ -0,0 +1,10 @@
+//go:build js
+
+package ws
+
+import "github.com/coder/websocket"
+
+func createDialOptions() *websocket.DialOptions {
+	// WASM version doesn't support HTTPClient
+	return &websocket.DialOptions{}
+}

shared/relay/client/dialer/ws/ws.go

@@ -32,9 +32,7 @@ func (d Dialer) Dial(ctx context.Context, address string) (net.Conn, error) {
 		return nil, err
 	}
 
-	opts := &websocket.DialOptions{
-		HTTPClient: httpClientNbDialer(),
-	}
+	opts := createDialOptions()
 
 	parsedURL, err := url.Parse(wsURL)
 	if err != nil {