tests for function handleScroll (apache#13896)

superset-frontend/src/dashboard/components/dnd/handleScroll/handleScroll.test.ts

@@ -0,0 +1,40 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+import handleScroll from '.';
+
+jest.useFakeTimers();
+
+const { scroll } = window;
+
+afterAll(() => {
+  window.scroll = scroll;
+});
+
+test('calling: "NOT_SCROLL_TOP" ,"SCROLL_TOP", "NOT_SCROLL_TOP"', () => {
+  window.scroll = jest.fn();
+
+  handleScroll('NOT_SCROLL_TOP');
+
+  expect(clearInterval).not.toBeCalled();
+
+  handleScroll('SCROLL_TOP');
+
+  handleScroll('NOT_SCROLL_TOP');
+  expect(clearInterval).toHaveBeenCalledWith(expect.any(Number));
+});