Testing Web Apps with Spring Framework

2. Testing Web Apps with Spring
Framework
October 18, 2014
JavaDay’14, Kyiv
Dmytro Chyzhykov

3. 3
Slides and Code Examples

4. - Build web applications with Spring Web MVC
- Familiar with mock objects unit testing (JUnit and Mockito)
4
Assumptions on Audience

5. Spring Controllers Testing
- Example Domain Model
- Subject Under Test
- Pure Unit Tests
Spring MVC Test Framework
- Standalone Server-Side Integration Tests
- Web Application Context Server-Side Integration Tests
Further materials
Q&A
5
Agenda

6. Example Domain Model
6

7. 7
Yandex.TV Service

8. 8
Domain
public class Channel {
private Integer id;
private String title;
!
// constructors, getters/setters
}

9. 9
Domain
public class Channel {
private Integer id;
private String title;
!
// constructors, getters/setters
}
DAO
@Repository
@Transactional
public interface ChannelRepository {
!
Channel findOne(Integer id);
!
}

10. Subject Under Test
10

11. 11
Subject Under Test
@Controller
@RequestMapping("/channels")
public class ChannelController {
}

12. 12
Subject Under Test
@Controller
@RequestMapping("/channels")
public class ChannelController {
@Autowired ChannelRepository channelRepository;
}

13. 13
Subject Under Test
@Controller
@RequestMapping("/channels")
public class ChannelController {
@Autowired ChannelRepository channelRepository;
!
@ResponseBody
@RequestMapping(value = "/{id}",
method = RequestMethod.GET)
public Channel getChannel(@PathVariable int id) {
// ...
}
}

14. 14
Subject Under Test
@Controller
@RequestMapping("/channels")
public class ChannelController {
@Autowired ChannelRepository channelRepository;
!
@ResponseBody
@RequestMapping(value = "/{id}",
method = RequestMethod.GET)
public Channel getChannel(@PathVariable int id) {
Channel channel = channelRepository.findOne(id);
!
if (channel != null) {
return channel;
}
!
// ...
}
}

15. 15
Subject Under Test
@Controller
@RequestMapping("/channels")
public class ChannelController {
@Autowired ChannelRepository channelRepository;
!
@ResponseBody
@RequestMapping(value = "/{id}",
method = RequestMethod.GET)
public Channel getChannel(@PathVariable int id) {
Channel channel = channelRepository.findOne(id);
!
if (channel != null) {
return channel;
}
!
throw new ChannelNotFoundException();
}
}

16. 16
Exception
@ResponseStatus(HttpStatus.NOT_FOUND)
public class ChannelNotFoundException
extends RuntimeException {
!
// constructors
!
}

17. ChannelController behaviour
- Positive test case
When we are looking for an existent channel by its id
- Negative test case
When we are looking for an absent channel by its id
17
What we are going to test

18. Pure Unit Testing
18

19. 19http://www.tubelinescaffolding.co.uk/industrial-scaffolding.htm
Scaffolding

20. 20
Unit Test Scaffolding
!
public class ChannelControllerTest {
}

21. 21
Unit Test Scaffolding
!
public class ChannelControllerTest {
@Mock
private ChannelRepository channelRepository;
}

22. 22
Unit Test Scaffolding
!
public class ChannelControllerTest {
@Mock
private ChannelRepository channelRepository;
!
@InjectMocks
private ChannelController channelController =
// optional new ChannelController();
}

23. 23
Unit Test Scaffolding
@RunWith(MockitoJUnitRunner.class)
public class ChannelControllerTest {
@Mock
private ChannelRepository channelRepository;
!
@InjectMocks
private ChannelController channelController =
// optional new ChannelController();
}

24. 24
Unit Test Scaffolding
@RunWith(MockitoJUnitRunner.class)
public class ChannelControllerTest {
@Mock
private ChannelRepository channelRepository;
!
@InjectMocks
private ChannelController channelController =
// optional new ChannelController();
!
!
@Mock
private Channel channel; // dummy
// test cases go here
}

25. 25
Positive Test Case
@Test
public void itShouldFindChannel() {
when(channelRepository.findOne(1))
.thenReturn(channel);
}

26. 26
Positive Test Case
@Test
public void itShouldFindChannel() {
when(channelRepository.findOne(1))
.thenReturn(channel);
!
assertThat(
channelController.getChannel(1), is(channel)
);
}

27. 27
Negative Test Case
@Test
public void itShouldNotFoundChannel() {
// optional
when(channelRepository.findOne(-1))
.thenReturn(null);
}

28. 28
Negative Test Case
@Test(expected = ChannelNotFoundException.class)
public void itShouldNotFoundChannel() {
// optional
when(channelRepository.findOne(-1))
.thenReturn(null);
!
channelController.getChannel(-1);
}

29. - Easy to write
- Incredibly fast (a few milliseconds per test case)
29
Pros

30. - Can use Spring mocks from org.springframework.mock.web
- MockHttpServletRequest/Response/Session
- MockMultipartFile
- MockFilterChain
…
- ModelAndViewAssert from org.springframework.test.web
to apply asserts on a resulting ModelAndView
30
Additional Capabilities on Demand

31. - A lot left untested
- Request mappings
- Type conversion
- Transactions
- Data binding
- Validation
- Filters
- …
- No Spring annotations used
- No DispatcherServlet interactions
- No actual Spring MVC configuration loaded
31
Caveats

32. 32http://futurama.wikia.com/wiki/File:GoodNewsEveryone.jpg
Good news everyone!

33. Spring MVC Test Framework
since 3.2
33

34. <dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>4.1.1.RELEASE</version>
</dependency>
34
Dependency

35. 35
Server-Side Integration Testing
without a Running Servlet Container
Web
Application
Context
DispatcherServlet
Tests
Controllers
MockMvc

36. - Response status, headers, content
- Spring MVC and Servlet specific results
- Model, flash, session, request attributes
- Mapped controller method
- Resolved exceptions
- Various options for asserting the response body
- JsonPath, XPath, XMLUnit
36
What can be tested

37. - Almost all template technologies are supported
- JSON, XML, Velocity, Freemarker, Thymeleaf, PDF etc.
- Except JSP (because it relies on Servlet Container)
- you can assert only on the selected JSP view name
- No actual redirecting or forwarding
- you can assert the redirected or forwarded URL
37
Testing View Layer

38. Standalone setup for testing one individual controller at a time
without actual Spring MVC configuration loading
38
MockMvc “Standalone” Setup
private ChannelController controller = //...
!
private MockMvc mockMvc;
!
public void setUp() {
mockMvc = MockMvcBuilders.standaloneSetup(controller)
.build();
}

39. 39
MockMvc “Standalone” Setup
mockMvc = MockMvcBuilders.standaloneSetup(controller)
.setValidator(...)
.setViewResolvers(...)
.setHandlerExceptionResolvers(...)
.setMessageConverters(...)
.setLocaleResolver(...)
.addFilter(...)
//...
.build();

40. With actual Spring MVC configuration loading
40
MockMvc Web App Context Setup
// Scaffolding is omitted
!
@Autowired
private WebApplicationContext wac;
!
@Before
public void setUp() {
mockMvc = MockMvcBuilders.webAppContextSetup(wac)
.build();
}

41. 41
Creating and Performing Requests
MockHttpServletRequestBuilder request =
MockMvcRequestBuilders.get("/channels/1")
.param("foo", "bar")
.header(...)
.cookie(...)
.locale(...)
.characterEncoding("UTF-8")
.accept("application/json")
.flashAttr("flash-key", "value")
// ...
.sessionAttr("key", “value");
!
!
mockMvc.perform(request);

42. 42
Applying Asserts
mockMvc.perform(request)
.andExpect(status().isOk())
.andExpect(content().contentType("application/json"))
.andExpect(jsonPath("$.id").value(1))
// ...
.andExpect(xpath("...")...)
.andExpect(header()...)
.andExpect(cookies()...)
.andExpect(model()...)
.andExpect(view()...)
.andExpect(content()...)
.andExpect(flash()...)
.andExpect(redirectedUrl("..."));

43. 43
Resolved Exception Assert
MvcResult mvcResult = mockMvc
.perform(...)
// ...
.andReturn();
!
assertThat(
mvcResult.getResolvedException(),
instanceOf(ChannelNotFoundException.class)
);

44. - MockMvcBuilders.* to set up MockMvc instances
- MockMvcRequestBuilders.* to create requests
- MockMvcResultMatchers.* for request result assertions on
44
Useful Static Imports

45. Standalone Server-Side
Integration Tests

46. 46
Scaffolding
@RunWith(MockitoJUnitRunner.class)
public class ChannelControllerStandaloneIT {
@Mock
private ChannelRepository channelRepository;
@InjectMocks
private ChannelController channelController =
new ChannelController();
}

47. 47
Scaffolding
@RunWith(MockitoJUnitRunner.class)
public class ChannelControllerStandaloneIT {
@Mock
private ChannelRepository channelRepository;
@InjectMocks
private ChannelController channelController =
new ChannelController();
private Channel channel = new Channel(1, "MTV");
}

48. 48
Scaffolding
@RunWith(MockitoJUnitRunner.class)
public class ChannelControllerStandaloneIT {
@Mock
private ChannelRepository channelRepository;
@InjectMocks
private ChannelController channelController =
new ChannelController();
private Channel channel = new Channel(1, "MTV");
!
private MockMvc mockMvc;
}

49. 49
Scaffolding
@RunWith(MockitoJUnitRunner.class)
public class ChannelControllerStandaloneIT {
@Mock
private ChannelRepository channelRepository;
@InjectMocks
private ChannelController channelController =
new ChannelController();
private Channel channel = new Channel(1, "MTV");
!
private MockMvc mockMvc;
!
@Before
public void setUp() {
mockMvc = standaloneSetup(channelController)
.build();
}
// test cases go here
}

50. 50
Positive Test Case
@Test
public void itShouldFindChannel() throws Exception {
when(channelRepository.findOne(1))
.thenReturn(channel);
}

51. 51
Positive Test Case
@Test
public void itShouldFindChannel() throws Exception {
when(channelRepository.findOne(1))
.thenReturn(channel);
!
mockMvc.perform(get("/channels/1")
.accept("application/json"))
}

52. 52
Positive Test Case
@Test
public void itShouldFindChannel() throws Exception {
when(channelRepository.findOne(1))
.thenReturn(channel);
!
mockMvc.perform(get("/channels/1")
.accept("application/json"))
.andExpect(status().isOk())
}

53. 53
Positive Test Case
@Test
public void itShouldFindChannel() throws Exception {
when(channelRepository.findOne(1))
.thenReturn(channel);
!
mockMvc.perform(get("/channels/1")
.accept("application/json"))
.andExpect(status().isOk())
.andExpect(content()
.contentType("application/json;charset=UTF-8"))
}

54. 54
Positive Test Case
@Test
public void itShouldFindChannel() throws Exception {
when(channelRepository.findOne(1))
.thenReturn(channel);
!
mockMvc.perform(get("/channels/1")
.accept("application/json"))
.andExpect(status().isOk())
.andExpect(content()
.contentType("application/json;charset=UTF-8"))
.andExpect(jsonPath("$.id").value(1))
}

55. 55
Positive Test Case
@Test
public void itShouldFindChannel() throws Exception {
when(channelRepository.findOne(1))
.thenReturn(channel);
!
mockMvc.perform(get("/channels/1")
.accept("application/json"))
.andExpect(status().isOk())
.andExpect(content()
.contentType("application/json;charset=UTF-8"))
.andExpect(jsonPath("$.id").value(1))
.andExpect(jsonPath("$.title").value("MTV"));
}

56. 56
Negative Test Case
@Test
public void itShouldNotFindChannel() throws Exception {
// optional
when(channelRepository.findOne(-1)).willReturn(null);
}

57. 57
Negative Test Case
@Test
public void itShouldNotFindChannel() throws Exception {
// optional
when(channelRepository.findOne(-1)).willReturn(null);
!
mockMvc.perform(get("/channels/-1")
.accept("application/json"))
}

58. 58
Negative Test Case
@Test
public void itShouldNotFindChannel() throws Exception {
// optional
when(channelRepository.findOne(-1)).willReturn(null);
!
mockMvc.perform(get("/channels/-1")
.accept("application/json"))
.andExpect(status().isNotFound());
}

59. 59
Negative Test Case
@Test
public void itShouldNotFindChannel() throws Exception {
// optional
when(channelRepository.findOne(-1)).willReturn(null);
!
MvcResult mvcResult = mockMvc
.perform(get("/channels/-1")
.accept("application/json"))
.andExpect(status().isNotFound())
.andReturn();
!
assertThat(mvcResult.getResolvedException(),
instanceOf(ChannelNotFoundException.class));
}

60. 60
Demo

61. ChannelController instantiated
Mock of ChannelRepository injected
MockMvc was set-upped
MockHttpServletRequest prepared
Executed via DispatcherServlet
Assertions applied on the resulting MockHttpServletResponse
Assertions applied on the resulting MvcResult
61
What happened

62. - Easy to write
- Uses Spring annotations
- Always interacts with DispatcherServlet
62
Pros

63. - A bit slow (about 1 second for the first test case)
- No Actual Spring MVC configuration loaded
63
Caveats

64. Web Application Context
Server-Side Integration Tests

65. 65
Scaffolding
!
!
!
!
!
!
!
!
public class ChannelControllerWebAppIT {
}

66. 66
Scaffolding
@RunWith(SpringJUnit4ClassRunner.class)
!
!
!
!
!
!
!
public class ChannelControllerWebAppIT {
}

67. 67
Scaffolding
@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
!
!
!
!
!
!
public class ChannelControllerWebAppIT {
@Autowired
private WebApplicationContext wac;
}

68. 68
Scaffolding
@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@ContextConfiguration({
"file:somewhere/servlet-context.xml",
"file:somewhere/persistence-context.xml"
})
!
!
public class ChannelControllerWebAppIT {
@Autowired
private WebApplicationContext wac;
}

69. 69
Scaffolding
@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@ContextConfiguration({
"file:somewhere/servlet-context.xml",
"file:somewhere/persistence-context.xml"
})
@Transactional
!
public class ChannelControllerWebAppIT {
@Autowired
private WebApplicationContext wac;
}

70. 70
Scaffolding
@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@ContextConfiguration({
"file:somewhere/servlet-context.xml",
"file:somewhere/persistence-context.xml"
})
@Transactional
@Sql(scripts = "classpath:test-channel-seeds.sql")
public class ChannelControllerWebAppIT {
@Autowired
private WebApplicationContext wac;
}

71. 71
Scaffolding
@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@ContextConfiguration({
"file:somewhere/servlet-context.xml",
"file:somewhere/persistence-context.xml"
})
@Transactional
@Sql(scripts = "classpath:test-channel-seeds.sql")
public class ChannelControllerWebAppIT {
@Autowired
private WebApplicationContext wac;
!
private MockMvc mockMvc;
!
@Before
public void setUp() {
mockMvc = webAppContextSetup(wac).build();
}
}

72. 72
Positive Test Case
@Test
public void itShouldFindChannel() throws Exception {
mockMvc.perform(get("/channels/1")
.accept("application/json"))
.andExpect(status().isOk())
.andExpect(content()
.contentType("application/json;charset=UTF-8"))
.andExpect(jsonPath("$.id").value(1))
.andExpect(jsonPath("$.title").value("MTV"));
}

73. 73
Negative Test Case
@Test
public void itShouldNotFindChannel() throws Exception {
MvcResult mvcResult = mockMvc
.perform(get("/channels/-1")
.accept("application/json"))
.andExpect(status().isNotFound())
.andReturn();
!
assertThat(mvcResult.getResolvedException(),
instanceOf(ChannelNotFoundException.class));
}

74. 74
Demo

75. Actual Web MVC application context loaded
MockHttpServletRequest prepared
Executed via DispatcherServlet
Assertions applied on the resulting MockHttpServletResponse
Assertions applied on the resulting MvcResult
75
What happened

76. - Easy to write
- Loads actual Spring MVC configuration (cacheable)
- Uses Spring annotations
- Always Interacts with DispatcherServlet
76
Pros

77. - Slower than the “Standalone” option (depends on amount of beans
in a particular Spring Mvc configuration)
- Does not replace end-to-end testing like Selenium
77
Caveats

78. Further Materials

79. Integration between Spring MVC Test Framework and HtmlUnit.
Repository: https://github.com/spring-projects/spring-test-htmlunit
Documentation: https://github.com/spring-projects/spring-test-
htmlunit/blob/master/src/asciidoc/index.adoc
79
Spring MVC Test HtmlUnit

80. Spring Framework Reference Documentation
Chapter 11.3 Integration Testing
http://docs.spring.io/spring/docs/current/spring-framework-reference/
htmlsingle/#integration-testing
spring-test artifact source code
https://github.com/spring-projects/spring-framework/tree/master/
spring-test
Spring MVC Showcase
https://github.com/spring-projects/spring-mvc-showcase
Code examples
https://github.com/ffbit/spring-mvc-test-framework-examples
80
Links

81. Webinar: Testing Web Applications with Spring 3.2
by Sam Brannen (Swiftmind) and Rossen Stoyanchev
https://www.youtube.com/watch?v=K6x8LE7Qd1Q
Spring Testing
by Mattias Severson
https://www.youtube.com/watch?v=LYVJ69h76nw
!
81
Videos

82. Thank you!
!
Questions?

83. ffbit@yandex-team.ru
Dmytro Chyzhykov
dmytro.chyzhykov@yandex.ru
ffbit
Senior Software Engineer
at Yandex Media Services
Kyiv, Ukraine
@dcheJava

84. 84
Slides and Code Examples

85. 85http://www.dotatalk.com/wp-content/uploads/2013/09/All-hail-King-Hypno-Toad.jpg