pool: add ConnectOption/WithDialer for per-call dialer override on Connect

pool_test.go

@@ -90,6 +90,51 @@ func TestPoolConnect(t *testing.T) {
 	})
 }
 
+func TestPoolConnectWithDialer(t *testing.T) {
+	t.Run("per-call dialer is used instead of pool dialer", func(t *testing.T) {
+		perCallUsed := false
+		perCallDialer := &honeybeetest.MockDialer{
+			DialContextFunc: func(ctx context.Context, url string, h http.Header) (types.Socket, *http.Response, error) {
+				perCallUsed = true
+				return honeybeetest.NewMockSocket(), nil, nil
+			},
+		}
+
+		// pool dialer should NOT be called
+		poolDialer := &honeybeetest.MockDialer{
+			DialContextFunc: func(context.Context, string, http.Header) (types.Socket, *http.Response, error) {
+				t.Error("pool dialer should not be called when per-call dialer is provided")
+				return nil, nil, fmt.Errorf("unexpected call")
+			},
+		}
+
+		cc := *transport.GetDefaultConnectionConfig()
+		cc.Dialer = poolDialer
+		pool, err := NewPool(context.Background(), &PoolConfig{
+			InboxBufferSize:  256,
+			EventsBufferSize: 10,
+			ConnectionConfig: cc,
+			WorkerConfig:     *GetDefaultWorkerConfig(),
+		}, nil)
+		assert.NoError(t, err)
+
+		err = pool.Connect("wss://test", WithDialer(perCallDialer))
+		assert.NoError(t, err)
+
+		honeybeetest.Eventually(t, func() bool {
+			select {
+			case e := <-pool.events:
+				return e.ID == "wss://test" && e.Kind == EventConnected
+			default:
+				return false
+			}
+		}, "expected connected event")
+
+		assert.True(t, perCallUsed, "per-call dialer was not used")
+		pool.Close()
+	})
+}
+
 func TestPoolClose(t *testing.T) {
 	t.Run("channels close after pool close", func(t *testing.T) {
 		pool, _ := NewPool(context.Background(), nil, nil)