Merge pull request #74 from neo4j/fix-null-stats

Return an empty stats if no stat is included in summary

Author: Zhen Li

driver/src/main/java/org/neo4j/driver/ResultSummary.java

@@ -24,9 +24,9 @@
  * The result summary of running a statement. The result summary interface can be used to investigate
  * details about the result, like the type of query run, how many and which kinds of updates have been executed,
  * and query plan and profiling information if available.
- * <p>
+ *
  * The result summary is only available after all result records have been consumed.
- * <p>
+ *
  * Keeping the result summary around does not influence the lifecycle of any associated session and/or transaction.
  */
 public interface ResultSummary
@@ -59,8 +59,7 @@ public interface ResultSummary
     /**
      * This describes how the database will execute your statement.
      *
-     * @throws IllegalStateException if {@link #hasPlan()} is false
-     * @return statement plan for the executed statement if available
+     * @return statement plan for the executed statement if available, otherwise null
      */
     Plan plan();
 
@@ -71,8 +70,7 @@ public interface ResultSummary
      * information about what each step of the plan did. That more in-depth version of the statement plan becomes
      * available here.
      *
-     * @throws IllegalStateException if {@link #hasProfile()} is false
-     * @return profiled statement plan for the executed statement if available
+     * @return profiled statement plan for the executed statement if available, otherwise null
      */
     ProfiledPlan profile();
 

driver/src/main/java/org/neo4j/driver/internal/summary/SimpleUpdateStatistics.java

@@ -22,6 +22,8 @@
 
 public class SimpleUpdateStatistics implements UpdateStatistics
 {
+    public static final SimpleUpdateStatistics EMPTY_STATS =
+            new SimpleUpdateStatistics( 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 );
     private final int nodesCreated;
     private final int nodesDeleted;
     private final int relationshipsCreated;

driver/src/main/java/org/neo4j/driver/internal/summary/SummaryBuilder.java

@@ -32,6 +32,8 @@
 import org.neo4j.driver.exceptions.ClientException;
 import org.neo4j.driver.internal.spi.StreamCollector;
 
+import static org.neo4j.driver.internal.summary.SimpleUpdateStatistics.EMPTY_STATS;
+
 public class SummaryBuilder implements StreamCollector
 {
     private final Statement statement;
@@ -136,7 +138,7 @@ public Statement statement()
             @Override
             public UpdateStatistics updateStatistics()
             {
-                return statistics;
+                return statistics == null ? EMPTY_STATS : statistics;
             }
 
             @Override

driver/src/test/java/org/neo4j/driver/internal/SummaryBuilderTest.java

@@ -0,0 +1,81 @@
+/**
+ * Copyright (c) 2002-2015 "Neo Technology,"
+ * Network Engine for Objects in Lund AB [http://neotechnology.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.neo4j.driver.internal;
+
+import org.junit.Test;
+
+import org.neo4j.driver.ResultSummary;
+import org.neo4j.driver.Statement;
+import org.neo4j.driver.UpdateStatistics;
+import org.neo4j.driver.internal.summary.SimpleUpdateStatistics;
+import org.neo4j.driver.internal.summary.SummaryBuilder;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.mockito.Mockito.mock;
+
+public class SummaryBuilderTest
+{
+    @Test
+    public void shouldReturnEmptyStatisticsIfNotProvided() throws Throwable
+    {
+        // Given
+        SummaryBuilder builder = new SummaryBuilder( mock( Statement.class ) );
+
+        // When
+        ResultSummary summary = builder.build();
+        UpdateStatistics stats = summary.updateStatistics();
+
+        // Then
+        assertEquals( stats, new SimpleUpdateStatistics( 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ) );
+    }
+
+
+    @Test
+    public void shouldReturnNullIfNoPlanProfileProvided() throws Throwable
+    {
+        // Given
+        SummaryBuilder builder = new SummaryBuilder( mock( Statement.class ) );
+
+        // When
+        ResultSummary summary = builder.build();
+
+        // Then
+        assertThat( summary.hasPlan(), equalTo( false ) );
+        assertThat( summary.hasProfile(), equalTo( false ) );
+        assertNull( summary.plan() );
+        assertNull( summary.profile() );
+    }
+
+
+    @Test
+    public void shouldReturnNullIfNoStatementTypeProvided() throws Throwable
+    {
+        // Given
+        SummaryBuilder builder = new SummaryBuilder( mock( Statement.class ) );
+
+        // When
+        ResultSummary summary = builder.build();
+
+        // Then
+        assertNull( summary.statementType() );
+    }
+}