get the most out of testing with spring 4.2

SPRINGONE2GX WASHINGTON, DC

© 2013-2015 Sam Brannen & Nicolas Fränkel and l icensed under a Creat ive Commons Attr ibut ion-NonCommercial l icense: ht tp: / /creat ivecommons.org/ l icenses/by-nc/3.0/

Get the Most out of Testing with Spring 4.2

Sam Brannen @sam_brannen

Nicolas Fränkel @nicolas_frankel


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

2

© 2013-2015 Sam Brannen & Nicolas Fränkel and l icensed under a Creat ive Commons Attr ibut ion-NonCommercial l icense: ht tp: / /creat ivecommons.org/ l icenses/by-nc/3.0/ 3

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

4


Learning Vaadin 7 Integration Testing from the Trenches

5

Nicolas’ Books


Agenda

•  Spring Events App

•  New in Spring 4.2

•  JUnit vs. TestNG

•  Spring Boot Tests

•  Spring Security Tests

•  Tips & Tricks

6


Show of hands…

7


Spring Events App

8


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

9


New in Spring Framework 4.2

10


@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

11


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

12


Convention-based Attribute Override

@Target(TYPE)@Retention(RUNTIME)@ContextConfiguration@Transactionalpublic @interface TransactionalTest { String[] locations() default {};}

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

13

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 { }

14

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

15


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 {};}

16

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 {}

17

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.

18


Unique Names for Embedded Databases

19

•  EmbeddedDatabaseBuilder

•  setName() – available since 3.0

•  generateUniqueName() – available since 4.2

•  <jdbc:embedded-database>

•  id – used as name since 3.0

o  but bad since the id is usually “dataSource”... not unique

•  database-name – available since 4.2

•  generate-name – available since 4.2


Ex: Embedded Database in Java Config

20

@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

21

<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 = ...)

22


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

23


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

24


Ex: SpringClassRule & SpringMethodRule

25

@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

26


MockMvc & HtmlUnit WebClient Setup

•  spring-test (4.2+) & htmlunit (2.18+)

•  MockMvcWebClientBuilder: several options, simplest case below

27

@Autowired WebApplicationContext wac;

WebClient webClient;

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


MockMvc & Selenium WebDriver Setup

•  spring-test (4.2+) & selenium-htmlunit-driver (2.47+)

•  MockMvcHtmlUnitDriverBuilder: several options, simplest case below

28

@Autowired WebApplicationContext wac;

WebDriver driver;

@Beforepublic void setup() { driver = 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

•  @DirtiesContext

•  New BEFORE_METHOD, BEFORE_CLASS, & BEFORE_EACH_TEST_METHOD modes

•  Requires DirtiesContextBeforeModesTestExecutionListener, enabled by default

29


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.

30


Odds & Ends (2)

•  @Commit •  Syntactical sugar for @Rollback(false)

•  Inlined statements with @Sql

•  For when a dedicated SQL script is overkill

•  Configured via a 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

31


@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

34


TestNG

•  Implemented annotations before JUnit

•  Richer lifecycle

•  Ordering of test methods

•  Concurrent test execution

35


JUnit

•  Unit for… unit testing!

•  Simplicity can be both a pro and a con

•  Lacks ordering… unless you use @FixMethodOrder

•  Single runner

•  Spring OR Mockito OR Parameterized

•  Rules to the rescue

36


Spring Boot Tests

37


Integration Tests with Spring Boot

•  @SpringApplicationConfiguration

•  Like @ContextConfiguration but with SpringApplicationContextLoader

•  Fully Loaded

•  @IntegrationTest

o  IntegrationTestPropertiesListener vs. @TestPropertySource

•  @WebIntegrationTest

•  Limiting scope of auto-configuration

•  @TestRepositoryConfig as example

38


Spring Security Tests

39


Spring Security – Test Annotations

•  WithSecurityContextTestExecutionListener

•  auto-detected

•  @WithMockUser

•  See RestEventsControllerIT in spring-events

•  @WithUserDetails

•  @WithSecurityContext

40


Spring Security & MockMvc

•  apply(springSecurity())

•  with(...) •  user(...)

•  authentication(...)

•  securityContext(...)

•  httpBasic(...)

•  perform(...)

•  formLogin()

•  logout()

41


Testing Tips & Tricks

42


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 + J

o  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

43


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

44


Integration Tests: Spring Boot vs. Spring Core

•  @SpringApplicationConfiguration vs. @ContextConfiguration

•  @EnableAutoConfiguration vs. hand-crafted test @Configuration

•  See @TestRepositoryConfig in spring-events app

45


Scope

•  Think about the scope of your test

•  SUT: System Under Test

•  The larger the SUT the smaller the number of tests

•  Mock or fake the dependencies of your SUT

46


End-to-end testing

•  A few nominal scenarios

•  Very brittle

•  Use the Page pattern

•  Decouples the page structure from the test itself

47


Integration Testing Challenges

•  Speed

•  Hard to diagnose

•  Brittle

48


Speed

•  Integration Tests are slow

•  Run Unit Tests before

•  No need to run IT if UT fail

•  If you use Maven, use the maven-failsafe-plugin

•  If you use Gradle, good luck !

49


Hard to Diagnose

•  Use small aptly named methods

•  Order them

•  E-commerce checkout

50


Brittle

•  All applications have infrastructure dependencies

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

•  They can be unavailable during testing

•  That sends a bad signal to developers

•  Fake them (or try to)

51


Fake Databases

•  Prefer a single schema per developer if you can

•  H2 has an Oracle compatibility mode

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

52


Fake Web Services

•  SOAP

•  SoapUI has an API

•  REST

•  Spark

53

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

return "Hello World!";});


Data source pool exhaustion check

•  Set the maximum number of connections in the pool to 1

54


Checking the database when a test fails

•  Commit your transactions in your tests

•  Use a clean setup strategy

•  Instead of a clean tear down

•  Use a file based database

•  H2

55


Testing is about Money

•  Not about having more test coverage than your neighbor

•  Think about ROI

56


JUnit Lambda

57


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

58


In closing…

59


Spring Resources

Spring Framework http://projects.spring.io/spring-framework

Spring Guides

http://spring.io/guides Spring JIRA

https://jira.spring.io Spring on GitHub

https://github.com/spring-projects/spring-framework Stack Overflow

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

60


Blogs

Spring Blog

http://spring.io/blog

Swiftmind Blog

http://www.swiftmind.com/blog

Nicolas Fränkel’s Blog

https://blog.frankel.ch

61


Sam Brannen

@sam_brannen

www.slideshare.net/sbrannen

www.swiftmind.com

Learn More. Stay Connected.

@springcentral Spring.io/video Nicolas Fränkel

@nicolas_frankel

get the most out of testing with spring 4.2

Technology