Get the Most out of Testing with Spring 4.2

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© 2013-2015 Sam Brannen & Nicolas Fränkel and licensed under a Creative Commons Attribution-NonCommercial license: http://creativecommons.org/l icenses/by-nc/3.0/

Get the Most out of Testingwith Spring 4.2

Sam Brannen@sam_brannen

Nicolas Fränkel@nicolas_frankel

© 2013-2015 Sam Brannen & Nicolas Fränkel and l icensed under a Creative CommonsAttr ibution-NonCommercial l icense: http:/ /creativecommons.org/ l icenses/by-nc/3.0/ 2

Sam Brannen• Spring and Enterprise Java Consultant @ Swiftmind

• Java Developer for over 17 years

• Spring Framework Core Committer since 2007• Component lead for spring-test• Creator of @AliasFor

• Spring Trainer

• Speaker on Spring, Java, and testing

• Swiss Spring User Group Lead


Your experts for Spring and Enterprise Java

Areas of expertise• Spring *• Java EE• Software Architecture• Software Engineering

Best Practices

Where you find us• Zurich, Switzerland• @swiftmind• http://

www.swiftmind.com


Nicolas Fränkel• Developer & Architect

• Consultant

• Teacher & Trainer

• Blogger

• Book Author


Learning Vaadin 7

Integration Testing from the Trenches

Nicolas’ Books

https://www.packtpub.com/web-development/learning-vaadin-7-second-edition

https://leanpub.com/integrationtest/


Agenda• Spring Events App

• New in Spring 4.2

• JUnit vs. TestNG

• Spring Boot Tests

• Spring Security Tests

• Tips & Tricks


Show of hands…


Spring Events App


The Spring Events Example Application• Spring Boot powered web app

• Simple POJO domain model: Event

• Transactional service layer

• Spring Data JPA repository layer

• Spring @MVC +Thymeleaf & REST presentation layer

• Spring Security

• https://github.com/sbrannen/spring-events

https://github.com/sbrannen/spring-events




New in Spring Framework 4.2


@AliasFor• New in Spring Framework 4.2, refined in 4.2.1

• Used to declare aliases between attributes within an annotation• e.g., locations and value in @ContextConfiguration, or

path and value in @RequestMapping

• Used in composed annotations to declare explicit overrides of attributes in meta-annotations• e.g., @Get, @Post, @GetJson, @TransactionalService• See Spring Composed project for examples• https://github.com/sbrannen/spring-composed

https://github.com/sbrannen/spring-composed

https://github.com/sbrannen/spring-composed


Composable Annotations w/ Overrides: pre 4.2• Composable annotations can override attributes of meta-annotations

• Purely convention-based• Matched by attribute name and type• Can lead to potential naming conflicts

• Cannot override the value attribute


Convention-based Attribute Override@Target(TYPE)@Retention(RUNTIME)@ContextConfiguration@Transactionalpublic @interface TransactionalTest { String[] locations() default {};}

@TransactionalTest(locations = "/order-test-config.xml")public class OrderRepositoryTests { }

seen as locations in @ContextConfiguration

redeclares locations attribute

declares locations attribute


Conflict w/ Convention-based Attribute Override@Target(TYPE)@Retention(RUNTIME)@ContextConfiguration@TestPropertySource@Transactionalpublic @interface TransactionalTest { String[] locations() default {};}

@TransactionalTest(locations = "/order-test-config.xml")public class OrderRepositoryTests { }

both declare locations attribute

ambiguous

which one?!


Composable Annotations w/ Overrides: post 4.2• Composable annotations can explicitly override attributes of meta-

annotations, even transitively

• Attributes within an annotation that effectively override the same attribute are treated as implicit aliases for each other

• Explicitly declared via @AliasFor• Can avoid potential naming conflicts

• Can even override the value attribute


Avoid Attribute Override Conflict w/ @AliasFor (1)@ContextConfiguration@TestPropertySource@Transactionalpublic @interface TransactionalTest {

@AliasFor(annotation = ContextConfiguration.class, attribute = "locations") String[] xmlFiles() default {};

@AliasFor(annotation = TestPropertySource.class, attribute = "locations") String[] propFiles() default {};}

both declare locations attribute

explicit

explicit


Avoid Attribute Override Conflict w/ @AliasFor (2)

@TransactionalTest( xmlFiles = "/order-test-config.xml", propFiles = "/order-test.properties")public class OrderRepositoryTests {}

seen as locations in @ContextConfiguration

seen as locations in @TestPropertySource


Embedded Databases – What’s in a Name?Q: Why should I care what my embedded database is named?A: Because you’ll run into problems if your DataSource config is imported from multiple places within your test suite.

Q: Why? Doesn’t it just create a new instance of the database?A: Recreating an embedded database within the same JVM doesn’t actually create anything: a second attempt simply connects to the existing one.

Q: Ummmm… What?!A: When you connect to an embedded database, it gets created if it doesn’t already exist; otherwise, you just connect to the existing instance. Assigning each one a unique name results in different JDBC connection URLs and thus different instances.


Unique Names for Embedded Databases• EmbeddedDatabaseBuilder

• setName() – since 3.0• generateUniqueName() – since 4.2

• <jdbc:embedded-database>• id – used as name since 3.0

o but bad since the id is usually “dataSource”... i.e., not unique• database-name – since 4.2• generate-name – since 4.2


Ex: Embedded Database in Java Config

@Beanpublic DataSource dataSource() { return new EmbeddedDatabaseBuilder() .generateUniqueName(true) .addScript("schema.sql") .addScript("user_data.sql") .build();}

New in Spring 4.2


Ex: Embedded Database XML Config

<jdbc:embedded-database id="dataSource" generate-name="true"> <jdbc:script location="classpath:/schema.sql" /> <jdbc:script location="classpath:/user_data.sql" /></jdbc:embedded-database>

New in Spring 4.2


Spring Cleaning• @TransactionConfiguration

• Deprecated in 4.2• @Rollback (and @Commit) now supported at the class level• Use @Transactional qualifiers

• AssertThrows• Deprecated in 3.x; gone in 4.2• JUnit: use @Test(expected = ...) or @Rule ExpectedException• TestNG: use @Test(expectedExceptions = ...)


Extension Points• ContextCache

• Now a public API with DefaultContextCache implementation

• DefaultTestContext, DefaultBootstrapContext, and DefaultCacheAwareContextLoaderDelegate• Now public classes, allowing for custom extensions

• TestContextBootstrapper• Now responsible for building the TestContext


Spring + JUnit … @Rules!• SpringJUnit4ClassRunner

• Serving the community since Spring 2.5 (2007)• But… can’t be used with other runners

o JUnit's Parameterized, MockitoJUnitRunner, etc.

• SpringClassRule & SpringMethodRule• Since Spring 4.2• Can be used with any JUnit runner!• Have to be used together• Provide full power of the Spring TestContext Framework


Ex: SpringClassRule & SpringMethodRule

@RunWith(Parameterized.class)@ContextConfigurationpublic class ParameterizedSpringRuleTests {

@ClassRule public static final SpringClassRule SPRING_CLASS_RULE = new SpringClassRule();

@Rule public final SpringMethodRule springMethodRule = new SpringMethodRule();


HtmlUnit, Selenium, & Geb• First-class support for HtmlUnit and Selenium in Spring MVC Test

• Initially a stand-alone project

• Incorporated into spring-test in Spring 4.2

• Page-based web app testing w/o a Servlet container

• The Selenium support can also be used with Geb


MockMvc & HtmlUnit WebClient Setup• spring-test (4.2+) & htmlunit (2.18+)

• MockMvcWebClientBuilder: several options, simplest case below

@Autowired WebApplicationContext wac;

WebClient webClient;

@Beforepublic void setup() { webClient = MockMvcWebClientBuilder .webAppContextSetup(wac).build();}


MockMvc & Selenium WebDriver Setup• spring-test (4.2+) & selenium-htmlunit-driver (2.47+)

• MockMvcHtmlUnitDriverBuilder: several options, simplest case below@Autowired WebApplicationContext wac;

WebDriver webDriver;

@Beforepublic void setup() { webDriver = MockMvcHtmlUnitDriverBuilder .webAppContextSetup(wac).build();}


Odds & Ends (1)• ReflectionTestUtils

• Now you can get or set static fields, including constants

• AopTestUtils• Obtain reference to target object hidden behind one or more Spring

proxies• Useful if your mock gets proxied (e.g., if your interface is @Transactional)

• @DirtiesContext• New BEFORE_METHOD, BEFORE_CLASS, & BEFORE_EACH_TEST_METHOD

modes• Requires DirtiesContextBeforeModesTestExecutionListener, enabled by

default


ReflectionTestUtils vs. Proper Design• Proper design mandates that we use the most narrow visibility

possible.• But it’s sometimes meaningful to test private methods, or change

values of final fields, etc.

• As a work-around, set the visibility to package (no keyword) and put the test class in the same package.• Guava provides the @VisibleForTesting annotation to document

this hack.

• ReflectionTestUtils is an alternative to such work-arounds that promotes proper design.


Odds & Ends (2)• @Commit

• Syntactical sugar for @Rollback(false)

• Inlined statements with @Sql• When a dedicated SQL script is overkill• Configured via the new statements attribute• Executed after SQL scripts in same @Sql annotation• Great for one-liners

• Spring MVC Test - MvcResult logging• New log(), print(OutputStream), and print(Writer) methods in

MockMvcResultHandlers complement existing print() method


@Test@Sql(statements = "DROP TABLE user IF EXISTS")@Sql( scripts = "/test-schema.sql", statements = "INSERT INTO user VALUES ('Dilbert')")public void userTest() { // code that uses the test schema and test user}

Ex: Inlined @Sql Statements


@Beforepublic void setUpMockMvc() { mockMvc = MockMvcBuilders .webAppContextSetup(wac) .alwaysDo(print(System.err)) .build();}

Ex: Logging MvcResult to STDERR


JUnit vs TestNG


JUnit• De facto testing framework for

Java

• Most popular library in the entire Java ecosystem• http://bit.ly/1iwwboO

http://bit.ly/1iwwboO




JUnit• Unit for… unit testing!

• Test methods are independent and isolated• Simplicity can be both a pro and a con• Can be used for integration testing, too

• Test methods are unordered• Unless you use @FixMethodOrder

• Single Runner• Spring OR Mockito OR Parameterized• Rules to the rescue


TestNG• Implemented test annotations before JUnit

• Richer lifecycle than JUnit

• Ordering and grouping of test methods

• Concurrent test execution


Spring Boot Tests


Integration Tests with Spring Boot• @SpringApplicationConfiguration

• Like @ContextConfiguration but with SpringApplicationContextLoader

• Fully Loaded• @IntegrationTest

o IntegrationTestPropertiesListener vs. @TestPropertySource• @WebIntegrationTest

• Limit scope of auto-configuration• @TestRepositoryConfig as example


Spring Security Tests


Spring Security Test Annotations• WithSecurityContextTestExecutionListener

• auto-detected

• @WithMockUser• See RestEventsControllerIT in spring-events

• @WithUserDetails

• @WithSecurityContext


Spring Security & MockMvc• apply(springSecurity())

• with(...)• user(...)• authentication(...)• securityContext(...)• httpBasic(...)

• perform(...)• formLogin()

• logout()


Testing Tips & Tricks


Eclipse• Define key bindings for executing tests quickly

• Alt + Shift + X… T too awkward to type frequently!• Sam’s personal settings:

o Run JUnit Test Ctrl + Jo Rerun JUnit Test Ctrl + Shift + J

• Set up content assist favorites for common static imports• org.junit.Assert OR org.assertj.core.api.Assertions• org.mockito.Mockito• org.springframework.test.web.servlet.request.MockMvcRequestBuilders• org.springframework.test.web.servlet.result.MockMvcResultMatchers


Context Caching• Granularity of context configuration files

• Goal: one entry point for production and one for testing• But… not very practical: you’ll need to support different scenarios• Too many constellations too many contexts • Too few constellations all tests use the same config

• Optimum use of the context cache• Avoid frequent use of @DirtiesContext• Cache statistics are logged at DEBUG level for category

org.springframework.test.context.cache


Integration Tests: Spring Boot vs. Spring Core• The key differences are speed and scope

• @SpringApplicationConfiguration vs. @ContextConfiguration

• @EnableAutoConfiguration vs. hand-crafted test @Configuration• See @TestRepositoryConfig in spring-events app


Scope• Think about the scope of your

test• SUT: Subject Under Test

• The larger the SUT, the smaller the number of tests

• Mock or fake the dependencies of your SUT


End-to-end Testing• A few nominal scenarios

• Very brittle• Use the Page pattern• Decouples the page structure from the test itself


Integration Testing Challenges• Speed

• Diagnosing the problem

• Brittleness


Speed• Integration tests are often slow

• Execute unit tests before integration tests• No need to run integration tests if unit tests fail

• Separate unit and integration tests in the build• Maven: use the maven-failsafe-plugin• Gradle: configure dependent Test tasks

o See spring-events for an example


Diagnosing the Problem• Consider an e-commerce checkout process

• Multi-step use case• Many places where things can go wrong

• Use small, focused, and aptly named methods

• Order and group methods• According to the steps in the process• Easy with TestNG; possible with JUnit


Brittleness• All applications have infrastructure dependencies

• Database, web services, file system, time, etc.

• External dependencies might be unavailable during testing• Sends a bad signal to developers• Causes builds to fail intermittently

• Solution: approximate the production environment• Mock or fake external dependencies


Developer & Test Databases• Embedded databases

• HSQL, H2, Derby• in-memory or persistent mode• H2 supports compatibility modes for Oracle, MySQL, etc.

• Developer databases• Use a single schema per developer if possible

• Be aware of the mismatch if you’re not using the same RDBMS in tests as in production


Fake Remote Web Services with SoapUI & Spark• SOAP

• SoapUI has an API• REST

• Spark

setPort(5678);get("/hello", (request, response) -> {

return "Hello World!";});


Mock Remote Web Services with Spring• In-memory mocks for remote Web Service endpoints

• Don’t actually connect to a server over the network

• SOAP – Spring Web Services• spring-ws-test module• MockWebServiceServer

• REST – Spring MVC REST• spring-test module• MockRestServiceServer


DataSource pool exhaustion check• Set the maximum number of connections in the pool to 1

• Tests blow up fast if connections are not returned to pool


Checking the database when a test failsIf a database related test is failing…

• Commit your transactions in your tests• Via @Commit or the TestTransaction API

• Use a clean setup strategy• Instead of a clean tear down strategy

• Use a file based database• Use persistent storage mode for embedded DBs• Inspect database state after failed test


Testing is about Saving Money• Not about having more test coverage than your neighbor

• Think about ROI


JUnit Lambda


Give back to the project that’s given us so much!• JUnit is the de facto standard testing

framework in the Java ecosystem• Last major release 10 years ago• Times have changed: Java 8, etc.

• Introducing … JUnit Lambda … the crowdfunding campaign to help make the next major release of JUnit a reality

• Pitch in if you can, & help spread the word!• @JUnitLambda• https://www.indiegogo.com/projects/junit-lambda

https://twitter.com/junitlambda

https://twitter.com/junitlambda

https://www.indiegogo.com/projects/junit-lambda

https://www.indiegogo.com/projects/junit-lambda


In closing…


Spring ResourcesSpring Frameworkhttp://projects.spring.io/spring-framework

Spring Guideshttp://spring.io/guides

Spring JIRAhttps://jira.spring.io

Spring on GitHubhttps://github.com/spring-projects/spring-framework

Stack Overflowspring, spring-test, spring-mvc, spring-boot, spring-security, …


Blogs

Spring Blog http://spring.io/blog

Swiftmind Blog http://www.swiftmind.com/blog

Nicolas Fränkel’s Blog https://blog.frankel.ch


Sam Brannen

@sam_brannen www.slideshare.net/sbrannen www.swiftmind.com

Learn More. Stay Connected.

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