[HUDI-709] Add unit test for UtilsCommand (#1686)

hudi-cli/src/main/java/org/apache/hudi/cli/commands/UtilsCommand.java

@@ -18,6 +18,7 @@
 
 package org.apache.hudi.cli.commands;
 
+import org.apache.hudi.common.util.StringUtils;
 import org.springframework.shell.core.CommandMarker;
 import org.springframework.shell.core.annotation.CliCommand;
 import org.springframework.shell.core.annotation.CliOption;
@@ -30,9 +31,15 @@ import org.springframework.stereotype.Component;
 public class UtilsCommand implements CommandMarker {
 
   @CliCommand(value = "utils loadClass", help = "Load a class")
-  public String loadClass(@CliOption(key = {"class"}, help = "Check mode") final String clazz) throws Exception {
-    Class klass = Class.forName(clazz);
-    return klass.getProtectionDomain().getCodeSource().getLocation().toExternalForm();
+  public String loadClass(@CliOption(key = {"class"}, help = "Check mode") final String clazz) {
+    if (StringUtils.isNullOrEmpty(clazz)) {
+      return "Class to be loaded can not be null!";
+    }
+    try {
+      Class klass = Class.forName(clazz);
+      return klass.getProtectionDomain().getCodeSource().getLocation().toExternalForm();
+    } catch (ClassNotFoundException e) {
+      return String.format("Class %s not found!", clazz);
+    }
   }
-
 }

hudi-cli/src/test/java/org/apache/hudi/cli/commands/TestUtilsCommand.java

@@ -0,0 +1,77 @@
+/*
+ * 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.
+ */
+
+package org.apache.hudi.cli.commands;
+
+import org.apache.hudi.cli.testutils.AbstractShellIntegrationTest;
+import org.apache.hudi.table.HoodieTable;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.shell.core.CommandResult;
+
+import static org.junit.jupiter.api.Assertions.assertAll;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * Test class for {@link org.apache.hudi.cli.commands.UtilsCommand}.
+ */
+public class TestUtilsCommand extends AbstractShellIntegrationTest {
+
+  /**
+   * Test case for success load class.
+   */
+  @Test
+  public void testLoadClass() {
+    String name = HoodieTable.class.getName();
+    CommandResult cr = getShell().executeCommand(String.format("utils loadClass --class %s", name));
+    assertAll("Command runs success",
+        () -> assertTrue(cr.isSuccess()),
+        () -> assertNotNull(cr.getResult().toString()),
+        () -> assertTrue(cr.getResult().toString().startsWith("file:")));
+  }
+
+  /**
+   * Test case for class not found.
+   */
+  @Test
+  public void testLoadClassNotFound() {
+    String name = "test.class.NotFound";
+    CommandResult cr = getShell().executeCommand(String.format("utils loadClass --class %s", name));
+
+    assertAll("Command runs success",
+        () -> assertTrue(cr.isSuccess()),
+        () -> assertNotNull(cr.getResult().toString()),
+        () -> assertEquals(cr.getResult().toString(), String.format("Class %s not found!", name)));
+  }
+
+  /**
+   * Test case for load null class.
+   */
+  @Test
+  public void testLoadClassNull() {
+    String name = "";
+    CommandResult cr = getShell().executeCommand(String.format("utils loadClass --class %s", name));
+
+    assertAll("Command runs success",
+        () -> assertTrue(cr.isSuccess()),
+        () -> assertNotNull(cr.getResult().toString()),
+        () -> assertEquals("Class to be loaded can not be null!", cr.getResult().toString()));
+  }
+}