Add Kruskal's Minimum Spanning Tree algorithm Test

Author: anandraj095

src/test/java/com/thealgorithms/graph/KruskalMSTTest.java

@@ -0,0 +1,50 @@
+package com.thealgorithms.graph;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * Test cases for Kruskal's Minimum Spanning Tree algorithm.
+ */
+class KruskalMSTTest {
+
+    @Test
+    void testFindMSTWithSimpleGraph() {
+        final int vertices = 4;
+
+        final List<Edge> edges = new ArrayList<>();
+        edges.add(new Edge(0, 1, 10));
+        edges.add(new Edge(0, 2, 6));
+        edges.add(new Edge(0, 3, 5));
+        edges.add(new Edge(1, 3, 15));
+        edges.add(new Edge(2, 3, 4));
+
+        final List<Edge> mst = KruskalMST.findMST(vertices, edges);
+
+        assertNotNull(mst, "MST should not be null");
+        assertEquals(vertices - 1, mst.size(), "MST should contain V-1 edges");
+
+        int totalWeight = 0;
+        for (final Edge edge : mst) {
+            totalWeight += edge.weight;
+        }
+
+        assertEquals(19, totalWeight, "Total weight of MST is incorrect");
+    }
+
+    @Test
+    void testFindMSTWithSingleVertex() {
+        final int vertices = 1;
+        final List<Edge> edges = new ArrayList<>();
+
+        final List<Edge> mst = KruskalMST.findMST(vertices, edges);
+
+        assertNotNull(mst, "MST should not be null");
+        assertEquals(0, mst.size(), "MST of single vertex graph should be empty");
+    }
+}