Adding test for cache verification

Signed-off-by: shikharj05 <[email protected]>

src/main/java/org/opensearch/security/support/SafeSerializationUtils.java

@@ -65,13 +65,13 @@ public final class SafeSerializationUtils {
     );
 
     private static final Set<String> SAFE_CLASS_NAMES = Collections.singleton("org.ldaptive.LdapAttribute$LdapAttributeValues");
-    private static final Map<Class<?>, Boolean> safeClassCache = new ConcurrentHashMap<>();
+    static final Map<Class<?>, Boolean> safeClassCache = new ConcurrentHashMap<>();
 
     static boolean isSafeClass(Class<?> cls) {
         return safeClassCache.computeIfAbsent(cls, SafeSerializationUtils::computeIsSafeClass);
     }
 
-    private static boolean computeIsSafeClass(Class<?> cls) {
+    static boolean computeIsSafeClass(Class<?> cls) {
         return cls.isArray() || SAFE_CLASSES.contains(cls) || SAFE_CLASS_NAMES.contains(cls.getName()) || isAssignableFromSafeClass(cls);
     }
 

src/test/java/org/opensearch/security/support/SafeSerializationUtilsTest.java

@@ -96,4 +96,24 @@ class CustomArrayList extends ArrayList<String> {}
         class CustomMap extends HashMap<String, Integer> {}
         assertTrue(SafeSerializationUtils.isSafeClass(CustomMap.class));
     }
+
+    @Test
+    public void testCaching() {
+        // First call should compute the result
+        boolean result1 = SafeSerializationUtils.isSafeClass(String.class);
+        assertTrue(result1);
+
+        // Second call should use cached result
+        boolean result2 = SafeSerializationUtils.isSafeClass(String.class);
+        assertTrue(result2);
+
+        // Verify that the cache was used (size should be 1)
+        assertEquals(1, SafeSerializationUtils.safeClassCache.size());
+
+        // Third call for a different class
+        boolean result3 = SafeSerializationUtils.isSafeClass(Integer.class);
+        assertTrue(result3);
+        // Verify that the cache was updated
+        assertEquals(2, SafeSerializationUtils.safeClassCache.size());
+    }
 }