[ZEPPELIN-6712] Fix CLI version options and restore CommandLineUtils

bin/zeppelin.sh

@@ -43,10 +43,11 @@ if [ -f /proc/self/cgroup ] && [ -n "$(command -v getent)" ]; then
 fi
 
 function usage() {
-    echo "Usage: bin/zeppelin.sh [--config <conf-dir>] [--run <noteId>]"
+    echo "Usage: bin/zeppelin.sh [--config <conf-dir>] [--run <noteId>] [--version|-v]"
 }
 
 POSITIONAL=()
+VERSION_ONLY=false
 while [[ $# -gt 0 ]]
 do
   key="$1"
@@ -61,6 +62,10 @@ do
     shift # past argument
     shift # past value
     ;;
+    -v|--version)
+    VERSION_ONLY=true
+    shift
+    ;;
     -h|--help)
         usage
         exit 0
@@ -81,7 +86,7 @@ bin="$(cd "${bin}">/dev/null; pwd)"
 
 check_java_version
 
-if [ "$1" == "--version" ] || [ "$1" == "-v" ]; then
+if [[ "${VERSION_ONLY}" == true ]]; then
     getZeppelinVersion
 fi
 

zeppelin-server/src/main/java/org/apache/zeppelin/utils/CommandLineUtils.java

@@ -0,0 +1,41 @@
+/*
+ * 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.zeppelin.utils;
+
+import java.util.Locale;
+
+import org.apache.zeppelin.util.Util;
+
+/**
+ * Command-line entry point invoked by getZeppelinVersion() in bin/common.sh.
+ */
+public class CommandLineUtils {
+  public static void main(String[] args) {
+    if (args.length == 0) {
+      return;
+    }
+
+    String usage = args[0].toLowerCase(Locale.US);
+    switch (usage) {
+      case "--version":
+      case "-v":
+        System.out.println(Util.getVersion());
+        break;
+      default:
+    }
+  }
+}

zeppelin-server/src/test/java/org/apache/zeppelin/utils/CommandLineUtilsTest.java

@@ -0,0 +1,91 @@
+/*
+ * 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.zeppelin.utils;
+
+import org.apache.zeppelin.util.Util;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * Unit tests for {@link CommandLineUtils} written in Given-When-Then style.
+ */
+class CommandLineUtilsTest {
+
+    /**
+     * Captures standard output during test execution.
+     */
+    private final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
+
+    /**
+     * Original System.out kept for restoration.
+     */
+    private final PrintStream originalOut = System.out;
+
+    @AfterEach
+    void restoreStdout() {
+        // Restore the original System.out after each test
+        System.setOut(originalOut);
+    }
+
+    @Test
+    @DisplayName("Given --version flag, when main is executed, then version is printed")
+    void givenVersionFlag_whenMain_thenPrintsVersion() {
+        // ----- Given -----
+        System.setOut(new PrintStream(outContent));
+        String expected = Util.getVersion();         // whatever the project returns
+
+        // ----- When -----
+        CommandLineUtils.main(new String[]{"--version"});
+
+        // ----- Then -----
+        assertEquals(expected, outContent.toString().trim());
+    }
+
+    @Test
+    @DisplayName("Given -v flag, when main is executed, then version is printed")
+    void givenShortVersionFlag_whenMain_thenPrintsVersion() {
+        // ----- Given -----
+        System.setOut(new PrintStream(outContent));
+        String expected = Util.getVersion();
+
+        // ----- When -----
+        CommandLineUtils.main(new String[]{"-v"});
+
+        // ----- Then -----
+        assertEquals(expected, outContent.toString().trim());
+    }
+
+    @Test
+    @DisplayName("Given no arguments, when main is executed, then nothing is printed")
+    void givenNoArgs_whenMain_thenPrintsNothing() {
+        // ----- Given -----
+        System.setOut(new PrintStream(outContent));
+
+        // ----- When -----
+        CommandLineUtils.main(new String[]{});
+
+        // ----- Then -----
+        assertEquals("", outContent.toString().trim());
+    }
+}