chore : add new tests for warning varification

Author: amirkian007

packages/compiler-core/__tests__/transforms/transformElement.spec.ts

@@ -1253,6 +1253,17 @@ describe('compiler: element transform', () => {
       )
     })
 
+    test('does not warn if has one component child and multiple comment children', () => {
+      checkWarning(
+        `<KeepAlive>
+            <!-- this should be ignored -->
+            <component :is="activeComponent"/>
+            <!-- this should be ignored -->
+         </KeepAlive>`,
+        false
+      )
+    })
+  
     test('warn if has multiple children', () => {
       checkWarning(
         `<KeepAlive>
@@ -1263,6 +1274,18 @@ describe('compiler: element transform', () => {
       )
     })
 
+    test('warn if has multiple component child and multiple comment children', () => {
+      checkWarning(
+        `<KeepAlive>
+          <!-- this should be ignored -->
+           <component :is="activeComponent"/>
+           <component :is="activeComponent2"/>
+          <!-- this should be ignored -->
+         </KeepAlive>`,
+        true
+      )
+    })
+
     test('should ignore comments', () => {
       expect(baseCompile(
         `<KeepAlive>