Merge branch 'master' into add-lambda-utils

Author: farheen-shaikh530

pom.xml

@@ -20,7 +20,7 @@
             <dependency>
                 <groupId>org.junit</groupId>
                 <artifactId>junit-bom</artifactId>
-                <version>5.13.0</version>
+                <version>5.13.1</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>

src/test/java/com/thealgorithms/sorts/TopologicalSortTest.java

@@ -3,6 +3,7 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertIterableEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import com.thealgorithms.sorts.TopologicalSort.Graph;
 import java.util.LinkedList;
@@ -59,4 +60,18 @@ public void failureTest() {
             + "Back edge: 6 -> 2";
         assertEquals(exception.getMessage(), expected);
     }
+    @Test
+    void testEmptyGraph() {
+        Graph graph = new Graph();
+        LinkedList<String> sorted = TopologicalSort.sort(graph);
+        assertTrue(sorted.isEmpty());
+    }
+    @Test
+    void testSingleNode() {
+        Graph graph = new Graph();
+        graph.addEdge("A", "");
+        LinkedList<String> sorted = TopologicalSort.sort(graph);
+        assertEquals(1, sorted.size());
+        assertEquals("A", sorted.getFirst());
+    }
 }