add qunit test

fix click subscription in events_engine (T1307313)

Author: GoodDayForSurf

packages/devextreme/testing/launch

@@ -41,7 +41,11 @@ function waitForRunner() {
 function openBrowser() {
     spawn(
         getBrowserCommand(),
-        [ 'http://localhost:' + PORT ],
+        [
+            '--js-flags=--expose-gc',
+            '--enable-precise-memory-info',
+            'http://localhost:' + PORT,
+        ],
         { shell: true, detached: true }
     );
 }

packages/devextreme/testing/tests/DevExpress.ui.events/event_nodes_disposing.tests.js

@@ -0,0 +1,32 @@
+import $ from 'jquery';
+
+QUnit.testStart(function() {
+    const markup = '<div id="dataGrid"></div>';
+    $('#qunit-fixture').html(markup);
+});
+
+QUnit.module('event nodes disposing');
+
+QUnit.test('should not leak memory when clicking on body with DxDataGrid on page', function(assert) {
+    $('#dataGrid').dxDataGrid({
+        dataSource: []
+    });
+
+    globalThis.gc();
+
+    const initialMemory = performance.memory.usedJSHeapSize;
+
+    for(let i = 0; i < 100; i++) {
+        $('body').trigger('click');
+    }
+
+    globalThis.gc();
+
+    const finalMemory = performance.memory.usedJSHeapSize;
+    const memoryDiff = finalMemory - initialMemory;
+
+    assert.ok(
+        memoryDiffMB <= 0,
+        `Memory should not leak. Memory diff: ${memoryDiff}B`
+    );
+});