test(angular): add support for multi-version testing (#25665)

angular/test/base/src/app/virtual-scroll/virtual-scroll.component.ts

@@ -0,0 +1,36 @@
+import { Component, OnInit, ViewChild } from '@angular/core';
+import { HeaderFn } from '@ionic/core';
+import { IonVirtualScroll } from '@ionic/angular';
+
+@Component({
+  selector: 'app-virtual-scroll',
+  templateUrl: './virtual-scroll.component.html',
+})
+export class VirtualScrollComponent {
+
+  @ViewChild(IonVirtualScroll, { static: true }) virtualScroll: IonVirtualScroll;
+
+  items = Array.from({length: 100}, (_, i) => ({ name: `${i}`, checked: true}));
+
+  itemHeight = () => 44;
+
+  myHeaderFn: HeaderFn = (_, index) => {
+    if ((index % 10) === 0) {
+      return `Header ${index}`;
+    }
+  }
+
+  myFooterFn: HeaderFn = (_, index) => {
+    if ((index % 5) === 0) {
+      return `Footer ${index}`;
+    }
+  }
+
+  addItems() {
+    console.log('adding items');
+    this.items.push(
+      { name: `New Item`, checked: true}
+    );
+    this.virtualScroll.checkEnd();
+  }
+}