feat: implement insert at Graph database manager

Signed-off-by: Otavio Santana <otaviopolianasantana@gmail.com>

jnosql-mapping/jnosql-mapping-graph/src/main/java/org/eclipse/jnosql/communication/graph/DefaultGraphDatabaseManager.java

@@ -15,6 +15,7 @@
 package org.eclipse.jnosql.communication.graph;
 
 import org.apache.tinkerpop.gremlin.structure.Graph;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
 import org.eclipse.jnosql.communication.semistructured.CommunicationEntity;
 import org.eclipse.jnosql.communication.semistructured.DeleteQuery;
 import org.eclipse.jnosql.communication.semistructured.SelectQuery;
@@ -37,6 +38,7 @@
  */
 public class DefaultGraphDatabaseManager implements GraphDatabaseManager {
 
+    static final String ID_PROPERTY = "_id";
     private final Graph graph;
 
     private DefaultGraphDatabaseManager(Graph graph) {
@@ -56,7 +58,10 @@ public String name() {
     @Override
     public CommunicationEntity insert(CommunicationEntity entity) {
         Objects.requireNonNull(entity, "entity is required");
-        return null;
+        Vertex vertex = graph.addVertex(entity.name());
+        entity.toMap().forEach(vertex::property);
+        entity.add(ID_PROPERTY, vertex.id());
+        return entity;
     }
 
     @Override

jnosql-mapping/jnosql-mapping-graph/src/test/java/org/eclipse/jnosql/communication/graph/DefaultGraphDatabaseManagerTest.java

@@ -0,0 +1,35 @@
+package org.eclipse.jnosql.communication.graph;
+
+import org.apache.tinkerpop.gremlin.structure.Graph;
+import org.assertj.core.api.SoftAssertions;
+import org.eclipse.jnosql.communication.semistructured.CommunicationEntity;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class DefaultGraphDatabaseManagerTest {
+
+    private GraphDatabaseManager databaseManager;
+
+    @BeforeEach
+    void setUp(){
+        Graph graph = GraphSupplier.INSTANCE.get();
+        this.databaseManager = DefaultGraphDatabaseManager.of(graph);
+    }
+
+    @Test
+    void shouldInsertEntity(){
+        var entity = CommunicationEntity.of("Person");
+        entity.add("name", "Ada Lovelace");
+        entity.add("age", 30);
+        var communicationEntity = databaseManager.insert(entity);
+        assertNotNull(communicationEntity);
+
+        SoftAssertions.assertSoftly(softly -> {
+            softly.assertThat(communicationEntity.find("name", String.class)).get().isEqualTo("Ada Lovelace");
+            softly.assertThat(communicationEntity.find("age", int.class)).get().isEqualTo(30);
+            softly.assertThat(communicationEntity.find(DefaultGraphDatabaseManager.ID_PROPERTY)).isPresent();
+        });
+    }
+}

jnosql-mapping/jnosql-mapping-graph/src/test/java/org/eclipse/jnosql/communication/graph/GraphSupplier.java

@@ -0,0 +1,23 @@
+package org.eclipse.jnosql.communication.graph;
+
+import org.apache.tinkerpop.gremlin.neo4j.structure.Neo4jGraph;
+import org.apache.tinkerpop.gremlin.structure.Graph;
+
+import java.io.File;
+import java.util.function.Supplier;
+import java.util.logging.Logger;
+
+import static java.lang.System.currentTimeMillis;
+
+public enum GraphSupplier implements Supplier<Graph> {
+    INSTANCE;
+
+    private static final Logger LOGGER = Logger.getLogger(GraphSupplier.class.getName());
+
+    @Override
+    public Graph get() {
+        var directory = new File("").getAbsolutePath() + "/target/jnosql-communication-graph/" + currentTimeMillis() + "/";
+        LOGGER.info("Starting Graph database at directory: " + directory);
+        return Neo4jGraph.open(directory);
+    }
+}