diff --git a/src/test/org/insa/utility/BinaryHeapTest.java b/src/test/org/insa/utility/BinaryHeapTest.java
index 88abc19..5a23ce5 100644
--- a/src/test/org/insa/utility/BinaryHeapTest.java
+++ b/src/test/org/insa/utility/BinaryHeapTest.java
@@ -1,68 +1,80 @@
 package org.insa.utility;
 
+import static org.junit.Assert.assertTrue;
 import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.fail;
 
+import java.util.Arrays;
 import java.util.stream.IntStream;
 
-import org.junit.jupiter.api.AfterAll;
-import org.junit.jupiter.api.AfterEach;
-import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.params.ParameterizedTest;
-import org.junit.jupiter.params.provider.MethodSource;
 
 public class BinaryHeapTest {
-	
-	private BinaryHeap<Integer> rangeHeap1;
-	
-	static IntStream dataRange1() {
-		return IntStream.range(0, 20);
-	}
-	
-	@BeforeAll
-    static void initAll() {
-		
-    }
+
+    private int[] data1 = IntStream.range(0, 20).toArray();
+    private int[] data2 = { 8, 1, 6, 3, 4, 5, 9 };
+
+    private BinaryHeap<Integer> heap1, heap2;
 
     @BeforeEach
     void init() {
-    		// Create the range heap
-    		this.rangeHeap1 = new BinaryHeap<Integer>();
-    		dataRange1().forEach((int x) -> rangeHeap1.insert(x));
+        // Create the range heap
+        this.heap1 = new BinaryHeap<Integer>();
+        this.heap2 = new BinaryHeap<Integer>();
+
+        for (int v: data1)
+            this.heap1.insert(v);
+        for (int v: data2)
+            this.heap2.insert(v);
     }
 
     @Test
     void testInsert() {
-    		BinaryHeap<Integer> heap = new BinaryHeap<Integer>();
-    		int size = 0;
-    		for (int x: dataRange1().toArray()) {
-    			heap.insert(x);
-    			size += 1;
-    			assertEquals(heap.size(), size);
-    		}
+        BinaryHeap<Integer> heap = new BinaryHeap<Integer>();
+        int size = 0;
+        for (int x: data1) {
+            heap.insert(x);
+            size += 1;
+            assertEquals(heap.size(), size);
+        }
+        assertEquals(data1.length, heap.size());
+
+        heap = new BinaryHeap<>();
+        size = 0;
+        for (int x: data2) {
+            heap.insert(x);
+            size += 1;
+            assertEquals(heap.size(), size);
+        }
+        assertEquals(data2.length, heap.size());
     }
-    
+
     @Test
     void testDeleteMin() {
-		int[] range1 = dataRange1().toArray();
-		int size = range1.length;
-		assertEquals(rangeHeap1.size(), size);
-		for (int x: range1) {
-			assertEquals(rangeHeap1.deleteMin().intValue(), x);
-			size -= 1;
-			assertEquals(rangeHeap1.size(), size);
-		}
+        // range 1 (sorted)
+        int[] range1 = data1;
+        int size = range1.length;
+        assertEquals(heap1.size(), size);
+        for (int x: range1) {
+            assertEquals(heap1.deleteMin().intValue(), x);
+            size -= 1;
+            assertEquals(heap1.size(), size);
+        }
+        assertEquals(heap1.size(), 0);
+        assertTrue(heap1.isEmpty());
+
+        // range 2 (was not sorted)
+        int[] range2 = Arrays.copyOf(data2, data2.length);
+        Arrays.sort(range2);
+        size = range2.length;
+        assertEquals(heap2.size(), size);
+        for (int x: range2) {
+            assertEquals(heap2.deleteMin().intValue(), x);
+            size -= 1;
+            assertEquals(heap2.size(), size);
+        }
+        assertEquals(heap2.size(), 0);
+        assertTrue(heap2.isEmpty());
     }
 
-    @AfterEach
-    void tearDown() {
-    }
-
-    @AfterAll
-    static void tearDownAll() {
-    }
-    
 }