feat: add option counting functions

Fixes: CLI-350

Author: toxn

pom.xml

@@ -24,7 +24,7 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>commons-cli</groupId>
   <artifactId>commons-cli</artifactId>
-  <version>1.10.1-SNAPSHOT</version>
+  <version>1.11.0-SNAPSHOT</version>
   <name>Apache Commons CLI</name>
   <inceptionYear>2002</inceptionYear>
   <description>

src/main/java/org/apache/commons/cli/CommandLine.java

@@ -300,6 +300,43 @@ public Option[] getOptions() {
         return options.toArray(Option.EMPTY_ARRAY);
     }
 
+    /**
+     * Gets the number of times this option appears in the command line.
+     *
+     * @param option the option.
+     * @return Number of times the option is present
+     * @since 1.11.0
+     */
+    public int getOptionCount(final Option option) {
+        int result = 0;
+        for (Option opt : options) {
+            if (Objects.equals(opt, option)) ++result;
+        }
+        return result;
+    }
+
+    /**
+     * Gets the number of times this option appears in the command line
+     * 
+     * @param optionChar the character name of the option.
+     * @return Number of times the option is present
+     * @since 1.11.0
+     */
+    public int getOptionCount(final char optionChar) {
+        return getOptionCount(String.valueOf(optionChar));
+    }
+
+    /**
+     * Gets the number of times this option appears in the command line
+     * 
+     * @param optionName the name of the option.
+     * @return Number of times the option is present
+     * @since 1.11.0
+     */
+    public int getOptionCount(final String optionName) {
+        return getOptionCount(resolveOption(optionName));
+    }
+
     /**
      * Gets the first argument, if any, of this option.
      *

src/test/java/org/apache/commons/cli/OptionCountTest.java

@@ -0,0 +1,61 @@
+/*
+  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
+
+      https://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.commons.cli;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class OptionCountTest {
+    final char    verbosityChar = 'v';
+    final String  verbosityStr  = String.valueOf(verbosityChar);
+    final Option  verbosity     = new Option(verbosityStr, "verbosity: use multiple times for more");
+    final Options options       = new Options().addOption(verbosity);
+
+    @Test
+    void testNoSwitch() throws ParseException {
+        final CommandLine cmdLine = new DefaultParser().parse(options, new String[]{});
+        assertEquals(0, cmdLine.getOptionCount(verbosity));
+    }
+
+    @Test
+    void testOneSwitch() throws ParseException {
+        final CommandLine cmdLine = new DefaultParser().parse(options, new String[]{"-v"});
+        assertEquals(1, cmdLine.getOptionCount(verbosity));
+        assertEquals(1, cmdLine.getOptionCount(verbosityStr));
+        assertEquals(1, cmdLine.getOptionCount(verbosityChar));
+    }
+
+    @Test
+    void testThreeSwitches() throws ParseException {
+        final CommandLine cmdLine = new DefaultParser().parse(options, new String[]{"-v", "-v", "-v"});
+        assertEquals(3, cmdLine.getOptionCount(verbosity));
+    }
+
+    @Test
+    void testThreeSwitchesCompact() throws ParseException {
+        final CommandLine cmdLine = new DefaultParser().parse(options, new String[]{"-vvv"});
+        assertEquals(3, cmdLine.getOptionCount(verbosity));
+    }
+
+    @Test
+    void testFiveSwitchesMixed() throws ParseException {
+        final CommandLine cmdLine = new DefaultParser().parse(options, new String[]{"-v", "-vvv", "-v"});
+        assertEquals(5, cmdLine.getOptionCount(verbosity));
+    }
+}