Fix

Author: pharret31

packages/devextreme/js/__internal/ui/stepper/stepper.ts

@@ -272,7 +272,6 @@ class Stepper extends CollectionWidgetAsync<StepperProperties> {
 
   _renderConnector(): void {
     if (this._connector) {
-      this._connector.option(this._getConnectorOptions());
       return;
     }
 
@@ -454,6 +453,10 @@ class Stepper extends CollectionWidgetAsync<StepperProperties> {
       case 'hintExpr':
         this._invalidate();
         break;
+      case 'items':
+        this._connector.option(this._getConnectorOptions());
+        super._optionChanged(args);
+        break;
       default:
         super._optionChanged(args);
     }

packages/devextreme/testing/tests/DevExpress.ui.widgets/stepper.tests.js

@@ -311,18 +311,16 @@ QUnit.module('Connector integration', moduleConfig, () => {
         });
     });
 
-    QUnit.test('connector should update its size if stepper repaint was called (T1312793)', function(assert) {
+    QUnit.test('connector should update its size on items mutation (T1312793)', function(assert) {
         const items = [{}, {}];
         this.reinit({ items });
 
         const sizeBefore = this.getConnector().option('size');
-
         items.push({});
-        this.instance.repaint();
-
+        this.instance.option('items', items);
         const sizeAfter = this.getConnector().option('size');
 
-        assert.strictEqual(sizeAfter > sizeBefore, true, 'connector size is updated after repaint');
+        assert.strictEqual(sizeAfter > sizeBefore, true, 'connector size is updated after items mutation');
     });
 });