Add argument to WebsocketErrorFunc

graphql/handler/transport/websocket.go

@@ -49,7 +49,24 @@ type (
 
 var errReadTimeout = errors.New("read timeout")
 
-var _ graphql.Transport = Websocket{}
+type WebsocketError struct {
+	Err error
+
+	// IsReadError flags whether the error occurred on read or write to the websocket
+	IsReadError bool
+}
+
+func (e WebsocketError) Error() string {
+	if e.IsReadError {
+		return fmt.Sprintf("websocket read: %v", e.Err)
+	}
+	return fmt.Sprintf("websocket write: %v", e.Err)
+}
+
+var (
+	_ graphql.Transport = Websocket{}
+	_ error             = WebsocketError{}
+)
 
 func (t Websocket) Supports(r *http.Request) bool {
 	return r.Header.Get("Upgrade") != ""
@@ -94,9 +111,12 @@ func (t Websocket) Do(w http.ResponseWriter, r *http.Request, exec graphql.Graph
 	conn.run()
 }
 
-func (c *wsConnection) handlePossibleError(err error) {
+func (c *wsConnection) handlePossibleError(err error, isReadError bool) {
 	if c.ErrorFunc != nil && err != nil {
-		c.ErrorFunc(c.ctx, err)
+		c.ErrorFunc(c.ctx, WebsocketError{
+			Err:         err,
+			IsReadError: isReadError,
+		})
 	}
 }
 
@@ -181,7 +201,7 @@ func (c *wsConnection) init() bool {
 
 func (c *wsConnection) write(msg *message) {
 	c.mu.Lock()
-	c.handlePossibleError(c.me.Send(msg))
+	c.handlePossibleError(c.me.Send(msg), false)
 	c.mu.Unlock()
 }
 
@@ -227,7 +247,7 @@ func (c *wsConnection) run() {
 		if err != nil {
 			// If the connection got closed by us, don't report the error
 			if !errors.Is(err, net.ErrClosed) {
-				c.handlePossibleError(err)
+				c.handlePossibleError(err, true)
 			}
 			return
 		}

graphql/handler/transport/websocket_test.go

@@ -356,7 +356,9 @@ func TestWebSocketErrorFunc(t *testing.T) {
 		h.AddTransport(transport.Websocket{
 			ErrorFunc: func(_ context.Context, err error) {
 				require.Error(t, err)
-				assert.Equal(t, err.Error(), "invalid message received")
+				assert.Equal(t, err.Error(), "websocket read: invalid message received")
+				assert.IsType(t, transport.WebsocketError{}, err)
+				assert.True(t, err.(transport.WebsocketError).IsReadError)
 				errFuncCalled <- true
 			},
 		})