unit test graph (#1479)

dolphinscheduler-common/src/test/java/org/apache/dolphinscheduler/common/graph/DAGTest.java

@@ -125,6 +125,10 @@ public class DAGTest {
     assertTrue(graph.containsEdge(1, 2));
     assertEquals(graph.getEdgesCount(), 1);
 
+    int node = 3;
+    graph.addNode(node, "v(3)");
+    assertFalse(graph.addEdge(node, node));
+
   }
 
 
@@ -347,4 +351,14 @@ public class DAGTest {
 
   }
 
+  @Test
+  public void testTopologicalSort4() {
+    clear();
+    try {
+      graph.topologicalSort();
+    } catch (Exception e) {
+      assertTrue(e.getMessage().contains("serious error: graph has cycle"));
+    }
+  }
+
 }

pom.xml

@@ -612,6 +612,7 @@
 				<version>${maven-surefire-plugin.version}</version>
 				<configuration>
 					<includes>
+						<include>**/common/graph/*.java</include>
 						<include>**/*CollectionUtilsTest.java</include><!--run test classes-->
 					</includes>
 					<!-- <skip>true</skip> -->