add test

fix click subscription in events_engine (T1307313)

Author: GoodDayForSurf

packages/devextreme-angular/tests/src/ui/data-grid.spec.ts

@@ -558,4 +558,36 @@ describe('Nested DxDataGrid', () => {
       }, 1000);
     }, 1000);
   });
+
+  it('should not memory leak after click if dx-data-grid is on page (T1307313)', () => {
+    TestBed.overrideComponent(TestContainerComponent, {
+      set: {
+        template: `<dx-data-grid [dataSource]="[]"></dx-data-grid>`,
+      },
+    });
+
+    const fixture = TestBed.createComponent(TestContainerComponent);
+    fixture.detectChanges();
+
+    for(let i = 0; i < 100; i++) {
+      document.body.click()
+    }
+    
+    fixture.detectChanges();
+    globalThis.gc();
+    
+    let memoryBefore = (performance as any).memory?.usedJSHeapSize
+
+    for(let i = 0; i < 100; i++) {
+      document.body.click()
+    }
+    
+    fixture.detectChanges();
+    globalThis.gc();
+    
+    const memoryDiff = (performance as any).memory?.usedJSHeapSize - memoryBefore;
+    console.log('------memory---->', memoryDiff / 1024);
+    
+    expect(memoryDiff <= 0).toBeTruthy();
+  })
 });