Added ARCCacheTest.java

Test cases added for the ARC

Author: devxadarsh

src/test/java/com/thealgorithms/datastructures/caches/ARCCacheTest.java

@@ -0,0 +1,69 @@
+package com.thealgorithms.datastructures.caches;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class ARCCacheTest {
+    private ARCCache<Integer, String> cache;
+
+    @BeforeEach
+    public void setUp() {
+        cache = new ARCCache<>(3); // Set capacity to 3 for testing purposes
+    }
+
+    @Test
+    public void testPutAndGet() {
+        cache.put(1, "Value1");
+        cache.put(2, "Value2");
+        cache.put(3, "Value3");
+
+        assertEquals("Value1", cache.get(1));
+        assertEquals("Value2", cache.get(2));
+        assertEquals("Value3", cache.get(3));
+    }
+
+    @Test
+    public void testEviction() {
+        cache.put(1, "Value1");
+        cache.put(2, "Value2");
+        cache.put(3, "Value3");
+
+        cache.put(4, "Value4"); // This should evict key 1
+
+        assertNull(cache.get(1)); // Key 1 should have been evicted
+        assertEquals("Value2", cache.get(2)); // Other keys should still be present
+        assertEquals("Value3", cache.get(3));
+        assertEquals("Value4", cache.get(4));
+    }
+
+    @Test
+    public void nullKeysAndValues() {
+        cache.put(null, "Value1");
+        cache.put(2, null);
+
+        assertEquals("Value1", cache.get(null));
+        assertNull(cache.get(2));
+        assertNull(cache.get(6));
+    }
+
+    @Test
+    public void testRepeatedGet() {
+        cache.put(1, "Value1");
+
+        // Repeated get calls should not affect eviction
+        cache.get(1);
+        cache.get(1);
+        cache.get(1);
+
+        // Adding new elements should still evict old ones
+        cache.put(2, "Value2");
+        cache.put(3, "Value3");
+        cache.put(4, "Value4");
+
+        assertNull(cache.get(2)); // Key 2 should have been evicted
+        assertEquals("Value1", cache.get(1)); // Other keys should still be present
+        assertEquals("Value3", cache.get(3)); // Other keys should still be present
+    }
+}