JavaLand - Integration Testing How-to

Integration Testing
How-to
Nicolas
Fränkel
März 2015

2https://leanpub.com/integrationtest
Me, myself and I
Developer & Architect as consultant
Wide range of businesses & customers
Teacher & Trainer
Speaker
Blogger
http://blog.frankel.ch/
http://morevaadin.com/

Also an author

hybris employee
E-commerce company
Rocks
Sends employees to Oktoberfest

Plan
Integration Testing
What is that?
Challenges
Solution hints
Testing with resource dependencies
Database
Web Services
Testing In-container
Spring & Spring MVC
JavaEE

There are many different kinds of testing
Unit Testing
Mutation Testing
GUI Testing
Performance Testing
Load Testing
Stress Testing
Endurance Testing
Security Testing
etc.

Unit Testing vs. Integration Testing
Unit Testing
Testing a unit in isolation
Integration Testing
Testing the collaboration of
multiple units
"Savatefouettéfigure1"byDaniel-PhotoDaniel.

A concrete example
Let’s take an example
A prototype car
"2011NissanLeafWAS20111040"byMariordoMarioRobertoDuranOrtiz-Ownwork

Unit Testing
Akin to testing each nut
and bolt separately

Integration Testing
Akin to going on a test
drive
"URE05e"byMarvinRaaijmakers-Ownwork.

Unit Testing + Integration Testing
Approaches are not
exclusive but
complementary
Would you take a prototype
car on test drive without
having tested only nuts and
bolts?
Would you manufacture a car
from a prototype having only
tested nuts and bolts but
without having tested it on
numerous test drives?

System Under Test
The SUT is what get
tested
Techniques from Unit
Testing can be re-used
Dependency Injection
Test doubles

Testing is about ROI
The larger the SUT
The more fragile the test
The less maintainable the test
The less the ROI
Thus, tests have to be
organized in a pyramidal
way
The bigger the SUT
The less the number of tests
Integration Testing
Test standard cases
Generally not error cases
http://martinfowler.com/bliki/TestPyramid.html

Integration Testing Challenges
Brittle
Dependent on external
resources
 Database(s)
 etc.
Slow
Dependent on external
resources
Hard to diagnose

How to cope
Separate Integration
Tests from Unit Tests
Fake required
infrastructure resources
Test in-container

But IT are still slow?!
Separating UT & IT
doesn’t make IT run
faster
But you can uncover
errors from UT faster
Fail Fast
It will speed testing
"Gepardjagt2(Acinonyxjubatus)"byMaleneThyssen-Ownwork.

Integration Testing and build
Available tools
Ant
Maven
Gradle
etc.
NewDevelopmentRecentlyFinishedonBristol'sCityCentrebyBrizzleboy

Maven lifecycle
…
compile
…
test
…
pre-integration-test
integration-test
post-integration-test
verify
…

Reminder on Surefire
Bound to the test phase
Runs by default
*Test
Test*
*TestCase

Failsafe
“Copy” of Surefire
Different defaults
*IT
IT*
*ITCase
One goal per lifecycle
phase
pre-integration-test
integration-test
post-integration-test
verify
Must be bound explicitly

Binding Failsafe - sample
<plugin>
<artifactId>maven-failsafe-plugin</artifactId>
<version>2.17</version>
<executions>
<execution>
<id>integration-test</id>
<goals>
<goal>integration-test</goal>
</goals>
<phase>integration-test</phase>
</execution>
<execution>
<id>verify</id>
<goals>
<goal>verify</goal>
</goals>
<phase>verify</phase>
</execution>
</executions>
</plugin>

Continuous Integration
Needs a build configured
Suggestions
Unit Tests run at each commit
Integration Tests run “regularly”
 Daily
 Hourly
 Depending on the context

Infrastructure dependencies
Database
Filesystem
Time
Message Oriented
Middleware
Mail server
FTP server
etc.

Mocks and infrastructure dependencies
To test your Service
Mock your DAO/repository
 Mockito
To test your DAO/repository
Mock your database???

Simple database use-case
Oracle database
Use an in-memory datasource
and hope for the best
Use Oracle Express and hope
for the best
Use a dedicated remote
schema for each developer
 And your DBAs will hate you

Reducing database gap risk
In-memory databases are easy to
setup
h2 is such a database
(successor of HSQL)
Compatibility modes for most
widespread DB
 jdbc:h2:mem:test;MODE=Oracle

Integration Testing with Web Services
Web Services also are an
infrastructure resource
Hosted on-site
Or outside
Different Web Services
types have different
solutions
RESTful
SOAP

Faking RESTful WS
Require an HTTP server
Requirements
Easy setup
Standalone
Embeddable in tests
Spring MVC?
Requires a servlet container
 (Not with Spring Boot)
Some code to write
Author:DwightSiplerfromStow,MA,USA

Spark to the rescue
Micro web framework
A la Sinatra
http://www.sparkjava.com/
Very few lines of code
Just wire to serve JSON files

Spark sample
import static spark.Spark.*;
import spark.*;
public class SparkSample{
public static void main(String[] args) {
setPort(5678);
get("/hello", (request, response) -> {
return "Hello World!";
});
get("/users/:name", (request, response) -> {
return "User: " + request.params(":name");
});
get("/private", (request, response) -> {
response.status(401);
return "Go Away!!!";
});
}
}

Faking SOAP web service
Possible to use Spark for SOAP
But unwieldy

SOAPUI
SOAPUI is the framework to test SOAP WS
Has a GUI
Good documentation
Understands
 Authentication
 Headers
 Etc.
Can be used to Fake SOAP WS

SOAPUI usage
Get WSDL
Either online
Or from a file
Create MockService
Craft the adequate response
Run the service
Point the dependency to localhost

Challenges to the previous scenario
Craft the adequate response?
More likely get one from the real WS
And tweak it
Running in an automated way
Save the project
Get the SOAPUI jar
Read the project and launch

SOAPUI automation
WsdlProject project = new WsdlProject();
String wsdlFile = "file:src/test/resources/ip2geo.wsdl";
WsdlInterface wsdlInterface =
importWsdl(project, wsdlFile, true)[0];
WsdlMockService fakeService =
project.addNewMockService("fakeService");
WsdlOperation wsdlOp =
wsdlInterface.getOperationByName("ResolveIP");
MockOperation fakeOp =
fakeService.addNewMockOperation(wsdlOp);
MockResponse fakeResponse =
fakeOp.addNewMockResponse("fakeResponse");
fakeResponse.setResponseContent(
"<soapenv:Envelope ...</soapenv:Envelope>");
runner = fakeService.start();

Faking Web Service in real-life
Use the same rules as for UT
Keep validation simple
Test one thing
 One Assert
 Or a set of related ones
Keep setup simple
Don’t put complex logic
 Don’t put too much logic
 Don’t put logic at all
Duplicate setup in each test
 Up to a point
Author:I,rolfB

Upping the ante
Testing collaboration is nice
Faking infrastructure dependencies is nice
But didn’t we forget the most important
dependency?

The container!
“Proprietary” container
Spring
Application Server
Tomcat
JBoss
<Place your favorite one here>

Spring
So far, we can test:
Beans which dependencies can be mocked (or not)
 Service
Beans that depend on fake resources
 Repository
What about the configuration?
In Unit Tests, we set dependencies
 The real configuration is not used
 Ergo, not tested!

Testing configuration
Configuration cannot be monolithic
Break down into fragments
Each fragment contains a set of either
 Real beans
 Fake beans
RudstonMonolithMay2013byAngelaFindlay

Data source configuration fragment management example
Different configuration
fragments
Production JNDI fragment
Test in-memory fragment

Data source configuration sample
<beans ...>
<jee:jndi-lookup id="ds" jndi-name="jdbc/MyDS" />
</beans>
<beans ...>
<bean id="ds" class="o.a.t.jdbc.pool.DataSource">
<property name="driverClassName”
value="org.h2.Driver" />
<property name="url" value="jdbc:h2:~/test" />
<property name="username" value="sa" />
<property name="maxActive" value="1" />
</bean>
</beans>

Fragment structure
1. Main fragment
Repository
Service
etc.
2. Prod DB fragment
3. Test DB fragment

Tips
Prevent coupling
No fragments reference in fragments
Use top-level assembly instead
 Tests
 Application Context
 Webapps
Pool exhaustion check
Set the maximum number of connections in the
pool to 1
Compile-time safety
Use JavaConfig
Not related to testing 

And now, how to test?
Get access to both
The entry point
The “end” point
Spring Test to the rescue
Integration with common
Testing frameworks
 JUnit
 TestNG
StLouisGatewayArch1916"byDirkBeyer-Ownwork.

Favor TestNG
Extra grouping
Per layer
Per use-case
Name your own
Extra lifecycle hooks
Better parameterization
Data Provider
Ordering of test methods

Spring TestNG integration
AbstractTestNGSpringContextTests
AbstractTransactionalTestNGSpringContextTests
Configurable context fragments
@ContextConfiguration
Inject any bean in the test class
If necessary, applicatonContext member from
superclass

Sample TestNG test with Spring
@ContextConfiguration(
classes = { MainCfg.class, AnotherCfg.class })
public class OrderIT extends
AbstractTestNGSpringContextTests {
@Autowired
private OrderService orderService;
@Test
public void should_do_this_and_that() {
orderService.order();
Assert.assertThat(...)
}
}

Testing with the DB (or other transactional resources)
Transactions
Bound to business
functionality
Implemented on Service layer
With DAO
Use explicit transaction
management
@Transactional

Transaction management tip
Tests fail… sometimes
How to audit state?
By default, Spring rollbacks
transactions
General configuration
@TransactionConfiguration(
defaultRollback = false
)
Can be overridden on a per-
method basis
 @Rollback(true)

Sample Transaction management
@ContextConfiguration
@TransactionConfiguration(defaultRollback = false)
public class OverrideDefaultRollbackSpringTest extends
AbstractTransactionalTestNGSpringContextTests {
@Test
@Rollback(true)
public void transaction_will_be_rollbacked() { ... }
@Test
public void transaction_wont_be_rollbacked() {
...
}
}

Spring MVC webapps Testing
Require a context hierachy
Parent as main context
Child as webapp context
@ContextHierarchy
Require a webapp configuration
@WebAppConfiguration

Spring MVC test sample
@WebAppConfiguration
@ContextHierarchy({
@ContextConfiguration(classes = MainConfig.class),
@ContextConfiguration(classes = WebConfig.class)
})
public class SpringWebApplicationTest
extends AbstractTestNGSpringContextTests {
...
}

Tools for testing webapps
HTML testing tools
Interact with HTML/CSS
 Fill this field
 Click on that button
HTTP testing tools
 Send HTTP requests
 Get HTTP responses

Drawback of previous approaches
Very low-level
Fragile!
Remember that testing is
about ROI
 Breaking tests with every
HTML/CSS change is the worst
way to have positive ROI
 (There are mitigation
techniques  out of scope)
Attribution:©MilanNykodym,CzechRepublic

Drawback of Testing with controllers as entry point
Bypass many URL-
related features
Interceptors
Spring Security
etc.
ControllerSCSI.JPGbyRosco

Spring Test to the rescue
Spring Test has a large
chunk dedicated to MVC
Since 3.2
Can test with URL as
entry-points
Fluent API with static
imports
CoastguardHelicopter(8016050677)"byPaulLucasfromLeicestershire,UK-CoastguardHelicopter

Spring MVC Test overview

MockMvc class responsibilities
Request builder
Configures the Fake request
Request matcher
Misc. assertions
Request handler
Do something
 OOB logger

Available configuration on Request Builder
HTTP method
GET
POST
etc.
HTTP related stuff
Headers
Parameters
Content
JavaEE related stuff
Request attributes
Session
etc.

Request Builder sample
MockHttpServletRequestBuilder builder =
get("/customer/{id}", 1234L)
.accept("text/html")
.param("lang", "en")
.secure(true);
GET /customer/1234?lang=en HTTP/1.1
Accept: text/html

Some matchers
Checks result is a
Forward
 Either exact
 Or regexp
Redirect
 Either exact
 Or regexp
JSON payload
asafetywaxmatchboxandmatchesbyAathavanjaffna

Some other matchers
Request class
Handler class
Controller
Content class
Cookie class
Status class
HTTP code
Flash class
(Attributes, not the techno)
View class
Model class
"OvejasenPatagonia-Argentina"bywrittecarlosantonio

The JavaEE world
JavaEE has unique
challenges
CDI has no explicit wiring
 You can @Veto you own
classes
 But no compiled ones
Different application servers
 Same specifications
 Different implementations

Deploy only what you want
Standalone API to deploy
only resources relevant
to the test
Just pick and choose
Maven Integration
Gradle too…

Shrinkwrap sample
String srcMainWebapp = "src/main/webapp/";
ShrinkWrap.create(WebArchive.class, "myWar.war")
.addClass(MyService.class)
.addPackage(MyModel.class.getPackage())
.addAsWebInfResource("persistence.xml",
"classes/META-INF/persistence.xml")
.addAsWebInfResource(
new File(srcMainWebapp, "WEB-INF/page/my.jsp"),
"page/my.jsp")
.addAsWebResource(
new File(srcMainWebapp, "script/my.js"),
"script/my.js")
.setWebXML("web.xml");

Maven integration sample
File[] libs = Maven.resolver()
.loadPomFromFile("pom.xml")
.importDependencies(COMPILE, RUNTIME).resolve()
.withTransitivity().asFile();
ShrinkWrap.create(WebArchive.class, "myWar.war")
.addAsLibraries(libs);

Different application servers
Abstraction layer to
Download
Deploy applications
Test
Container adapters
TomEE
JBoss
Weld
etc.
Full Maven integration

Arquillian Test sample
public class ArquillianSampleIT extends Arquillian {
@Inject
private MyService myService;
@Deployment
public static JavaArchive createDeployment() {
return ...;
}
@Test
public void should_handle_service() {
Object value = myService.handle();
Assert.assertThat(...);
}
}

Arquillian configuration sample
<arquillian xmlns="http://jboss.org/schema/arquillian"
xmlns:xsi="..."
xsi:schemaLocation="
http://jboss.org/schema/arquillian
http://jboss.org/schema/arquillian/arquillian_1_0.xsd">
<container qualifier="tomee" default="true">
<configuration>
<property name="httpPort">-1</property>
<property name="stopPort">-1</property>
</configuration>
</arquillian>

https://leanpub.com/integrationtest
Twitter: @itfromtrenches

JavaLand - Integration Testing How-to

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