refactor: Enhance docs, add more tests in PhoneticAlphabetConverter

Author: Hardvan

src/main/java/com/thealgorithms/conversions/PhoneticAlphabetConverter.java

@@ -58,9 +58,25 @@ private PhoneticAlphabetConverter() {
         PHONETIC_MAP.put('9', "Nine");
     }
 
+    /**
+     * Converts text to the NATO phonetic alphabet.
+     * Steps:
+     * 1. Convert the text to uppercase.
+     * 2. Iterate over each character in the text.
+     * 3. Get the phonetic equivalent of the character from the map.
+     * 4. Append the phonetic equivalent to the result.
+     * 5. Append a space to separate the phonetic equivalents.
+     * 6. Return the result.
+     *
+     * @param text the text to convert
+     * @return the NATO phonetic alphabet
+     */
     public static String textToPhonetic(String text) {
         StringBuilder phonetic = new StringBuilder();
         for (char c : text.toUpperCase().toCharArray()) {
+            if (Character.isWhitespace(c)) {
+                continue;
+            }
             phonetic.append(PHONETIC_MAP.getOrDefault(c, String.valueOf(c))).append(" ");
         }
         return phonetic.toString().trim();

src/test/java/com/thealgorithms/conversions/PhoneticAlphabetConverterTest.java

@@ -2,20 +2,26 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
-import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
 
 public class PhoneticAlphabetConverterTest {
 
-    @Test
-    public void testTextToPhonetic() {
-        assertEquals("Alpha Bravo", PhoneticAlphabetConverter.textToPhonetic("AB"));
-        assertEquals("Alpha Bravo Charlie", PhoneticAlphabetConverter.textToPhonetic("ABC"));
-        assertEquals("Alpha One Bravo Two Charlie Three", PhoneticAlphabetConverter.textToPhonetic("A1B2C3"));
-        assertEquals("Hotel Echo Lima Lima Oscar", PhoneticAlphabetConverter.textToPhonetic("Hello"));
-        assertEquals("One Two Three", PhoneticAlphabetConverter.textToPhonetic("123"));
-        assertEquals("Alpha Bravo Charlie Delta Echo Foxtrot Golf Hotel India Juliett Kilo Lima Mike November Oscar Papa Quebec Romeo Sierra Tango Uniform Victor Whiskey X-ray Yankee Zulu Zero One Two Three Four Five Six Seven Eight Nine",
-            PhoneticAlphabetConverter.textToPhonetic("ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"));
-        assertEquals("Alpha Bravo Charlie Delta Echo Foxtrot Golf Hotel India Juliett Kilo Lima Mike November Oscar Papa Quebec Romeo Sierra Tango Uniform Victor Whiskey X-ray Yankee Zulu Zero One Two Three Four Five Six Seven Eight Nine",
-            PhoneticAlphabetConverter.textToPhonetic("abcdefghijklmnopqrstuvwxyz0123456789"));
+    @ParameterizedTest
+    @CsvSource({
+        "'AB', 'Alpha Bravo'", "'ABC', 'Alpha Bravo Charlie'", "'A1B2C3', 'Alpha One Bravo Two Charlie Three'", "'Hello', 'Hotel Echo Lima Lima Oscar'", "'123', 'One Two Three'",
+        "'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789', 'Alpha Bravo Charlie Delta Echo Foxtrot Golf Hotel India Juliett Kilo Lima Mike November Oscar Papa Quebec Romeo Sierra Tango Uniform Victor Whiskey X-ray Yankee Zulu Zero One Two Three Four Five Six Seven Eight Nine'",
+        "'abcdefghijklmnopqrstuvwxyz0123456789', 'Alpha Bravo Charlie Delta Echo Foxtrot Golf Hotel India Juliett Kilo Lima Mike November Oscar Papa Quebec Romeo Sierra Tango Uniform Victor Whiskey X-ray Yankee Zulu Zero One Two Three Four Five Six Seven Eight Nine'",
+        "'', ''", // Empty string case
+        "'A B C', 'Alpha Bravo Charlie'", // String with spaces
+        "'A@B#C', 'Alpha @ Bravo # Charlie'", // Special characters
+        "'A B C 123', 'Alpha Bravo Charlie One Two Three'", // Mixed letters, digits, and spaces
+        "'a b c', 'Alpha Bravo Charlie'", // Lowercase letters with spaces
+        "'123!@#', 'One Two Three ! @ #'", // Numbers with special characters
+        "'HELLO WORLD', 'Hotel Echo Lima Lima Oscar Whiskey Oscar Romeo Lima Delta'" // Words with space
+    })
+    public void
+    testTextToPhonetic(String input, String expectedOutput) {
+        assertEquals(expectedOutput, PhoneticAlphabetConverter.textToPhonetic(input));
     }
 }