The basic pattern of unit testing with Neo4j is illustrated by the following example.
To access the Neo4j testing facilities you should have the neo4j-kernel
tests.jar on the classpath during tests.
You can download it from Maven Central: org.neo4j:neo4j-kernel.
Using Maven as a dependency manager you would typically add this dependency together with JUnit and Hamcrest like so:
Maven dependency.
<project> ... <dependencies> <dependency> <groupId>org.neo4j</groupId> <artifactId>neo4j-kernel</artifactId> <version>1.9</version> <type>test-jar</type> <scope>test</scope> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit-dep</artifactId> <version>4.11</version> <scope>test</scope> </dependency> <dependency> <groupId>org.hamcrest</groupId> <artifactId>hamcrest-all</artifactId> <version>1.3</version> <scope>test</scope> </dependency> ... </dependencies> ... </project>
Observe that the <type>test-jar</type>
is crucial.
Without it you would get the common neo4j-kernel
jar, not the one containing the testing facilities.
With that in place, we’re ready to code our tests.
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For the full source code of this example see: Neo4jBasicDocTest.java |
Before each test, create a fresh database:
@Before public void prepareTestDatabase() { graphDb = new TestGraphDatabaseFactory().newImpermanentDatabase(); }
After the test has executed, the database should be shut down:
@After public void destroyTestDatabase() { graphDb.shutdown(); }
During a test, create nodes and check to see that they are there, while enclosing write operations in a transaction.
Transaction tx = graphDb.beginTx(); Node n = null; try { n = graphDb.createNode(); n.setProperty( "name", "Nancy" ); tx.success(); } catch ( Exception e ) { tx.failure(); } finally { tx.finish(); } // The node should have an id greater than 0, which is the id of the // reference node. assertThat( n.getId(), is( greaterThan( 0L ) ) ); // Retrieve a node by using the id of the created node. The id's and // property should match. Node foundNode = graphDb.getNodeById( n.getId() ); assertThat( foundNode.getId(), is( n.getId() ) ); assertThat( (String) foundNode.getProperty( "name" ), is( "Nancy" ) );
If you want to set configuration parameters at database creation, it’s done like this:
Map<String, String> config = new HashMap<String, String>(); config.put( "neostore.nodestore.db.mapped_memory", "10M" ); config.put( "string_block_size", "60" ); config.put( "array_block_size", "300" ); GraphDatabaseService db = new TestGraphDatabaseFactory() .newImpermanentDatabaseBuilder() .setConfig( config ) .newGraphDatabase();
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