The Java ecosystem is very rich both for production and testing code; testing code is just as important as producing code. In this session, we’ll explore how to fake out REST APIs to test out client code; fake out REST clients to test out server code; write better parameterized tests; take care of concurrency related events; spy/mock/stub out collaborators to ensure cleaner and isolated tests; and more.

1. TESTING LIBRARIES
FOR FUN & PROFIT
BEWARE: INCREASED PRODUCTIVITY AHEAD@IXCHELRUIZ — PRINCIPAL CONSULTANT
TRIVADIS AG

2. ixchelruiz
AIM
Rest APIs
Fake Servers
Fake Clients
Parameterized Tests
Spy, Mock, Stub

3. ixchelruiz
Open Source

4. ixchelruiz

5. ixchelruiz
REST API

6. ixchelruiz
WHAT? WHY? WHO? WHEN?
REpresentational State Transfer.
“Architectural style for distributed hypermedia
systems, as it has been developed to represent the
model for how the modern Web should work. REST
provides a set of architectural constraints that,
when applied as a whole, emphasizes scalability of
component interactions, generality of interfaces,
independent deployment of components, and
intermediary components to reduce interaction
latency, enforce security, and encapsulate legacy
systems”

7. ixchelruiz
WHAT? WHY? WHO? WHEN?
REpresentational State Transfer.
“Architectural style for distributed hypermedia
systems, as it has been developed to represent the
model for how the modern Web should work. REST
provides a set of architectural constraints that,
when applied as a whole, emphasizes scalability of
component interactions, generality of interfaces,
independent deployment of components, and
intermediary components to reduce interaction
latency, enforce security, and encapsulate legacy
systems”

8. ixchelruiz
WHAT? WHY? WHO? WHEN?
REpresentational State Transfer.
“Architectural style for distributed hypermedia
systems, as it has been developed to represent the
model for how the modern Web should work. REST
provides a set of architectural constraints that,
when applied as a whole, emphasizes scalability of
component interactions, generality of interfaces,
independent deployment of components, and
intermediary components to reduce interaction
latency, enforce security, and encapsulate legacy
systems”
— Roy Thomas Fielding
https://www.ics.uci.edu/~fielding/pubs/dissertation/web_arch_domain.htm

9. ixchelruiz
WHAT? WHO? WHY? WHEN?
REpresentational State Transfer.
“Architectural style for distributed hypermedia
systems, as it has been developed to represent the
model for how the modern Web should work. REST
provides a set of architectural constraints that,
when applied as a whole, emphasizes scalability of
component interactions, generality of interfaces,
independent deployment of components, and
intermediary components to reduce interaction
latency, enforce security, and encapsulate legacy
systems”
— Roy Thomas Fielding (2000)
https://www.ics.uci.edu/~fielding/pubs/dissertation/web_arch_domain.htm

10. ixchelruiz
STATE OF AFFAIRS
Heterogeneous collection of
terminals, workstations, servers
and supercomputers.

11. ixchelruiz
STATE OF AFFAIRS
Heterogeneous collection of
terminals, workstations, servers
and supercomputers.

12. ixchelruiz
STATE OF AFFAIRS
Evolution of REST APIs
(Model, Documentation,
Implementation)

13. ixchelruiz
OPEN API 3.0OAI/OPENAPI-SPECIFICATION

14. ixchelruiz
WHAT? WHY? WHO? WHEN?
“Define a standard, language-agnostic interface to
REST APIs which allows both humans and
computers to discover and understand the
capabilities of the service without access to source
code, documentation, or through network traffic
inspection. When properly defined via OpenAPI, a
consumer can understand and interact with the
remote service with a minimal amount of
implementation logic.”

15. ixchelruiz
WHAT? WHY? WHO? WHEN?
“Define a standard, language-agnostic interface to
REST APIs which allows both humans and
computers to discover and understand the
capabilities of the service without access to source
code, documentation, or through network traffic
inspection. When properly defined via OpenAPI, a
consumer can understand and interact with the
remote service with a minimal amount of
implementation logic.”
#vendorNeutral #portable #open #specification #technical
#metadata

16. ixchelruiz
WHAT? WHY? WHO? WHEN?
“Define a standard, language-agnostic interface to
REST APIs which allows both humans and
computers to discover and understand the
capabilities of the service without access to source
code, documentation, or through network traffic
inspection. When properly defined via OpenAPI, a
consumer can understand and interact with the
remote service with a minimal amount of
implementation logic.”
#vendorNeutral #portable #open #specification #technical
#metadata
— OpenApi Initiative

17. ixchelruiz
WHAT? WHO? WHY? WHEN?
“Define a standard, language-agnostic interface to
REST APIs which allows both humans and
computers to discover and understand the
capabilities of the service without access to source
code, documentation, or through network traffic
inspection. When properly defined via OpenAPI, a
consumer can understand and interact with the
remote service with a minimal amount of
implementation logic.”
#vendorNeutral #portable #open #specification #technical
#metadata
— OpenApi Initiative (Jul 26, 2017)

18. ixchelruiz
OPEN API INITIATIVE

19. ixchelruiz
WHAT? WHY? WHO? WHEN?
“The OpenAPI Initiative (OAI) was created by a
consortium of forward-looking industry experts
who recognize the immense value of standardizing
on how REST APIs are described. Provides an open
source, technical community, within which industry
participants may easily contribute to building a
vendor-neutral, portable and open specification for
providing technical metadata for REST APIs. The
OAI is a collaborative project under the guidance of
the The Linux Foundation”

20. ixchelruiz
WHAT? WHY? WHO? WHEN?
“The OpenAPI Initiative (OAI) was created by a
consortium of forward-looking industry experts
who recognize the immense value of standardizing
on how REST APIs are described. Provides an open
source, technical community, within which
industry participants may easily contribute to
building a vendor-neutral, portable and open
specification for providing technical metadata for
REST APIs. The OAI is a collaborative project under
the guidance of the The Linux Foundation”

21. ixchelruiz
WHAT? WHY? WHO? WHEN?

22. ixchelruiz
WHAT? WHY? WHO? WHEN?
2015

23. ixchelruiz
Tools that support OpenApi 3.0
http://openapi.tools

24. ixchelruiz
PROFIT
OPEN API
INITIATIVE & SPEC

25. ixchelruiz
OPEN API 3.0
“Define a standard, language-agnostic interface to
REST APIs which allows both humans and
computers to discover and understand the
capabilities of the service without access to source
code, documentation, or through network traffic
inspection. When properly defined via OpenAPI,
a consumer can understand and interact with the
remote service with a minimal amount of
implementation logic.”
— Open API Initiative

26. ixchelruiz
OPEN API 3.0
“Define a standard, language-agnostic interface to
REST APIs which allows both humans and
computers to discover and understand the
capabilities of the service without access to source
code, documentation, or through network traffic
inspection. When properly defined via OpenAPI,
a consumer can understand and interact with the
remote service with a minimal amount of
implementation logic.”
— Open API Initiative

27. ixchelruiz
REST API
SPEC

28. ixchelruiz
DEMO

29. ixchelruiz
https://editor.swagger.io

30. ixchelruiz
SWAGGER
EDITOR

31. ixchelruiz
https://github.com/swagger-api/swagger-editor

32. ixchelruiz

33. ixchelruiz
SWAGGER
CODEGEN

34. ixchelruiz
https://github.com/swagger-api/swagger-codegen

35. ixchelruiz
https://github.com/swagger-api/swagger-codegen/wiki/Server-stub-generator-HOWTO

36. ixchelruiz
WIREMOCK

37. ixchelruiz
http://wiremock.org

38. ixchelruiz
DEMO

39. ixchelruiz

40. ixchelruiz
Standalone

41. ixchelruiz
Configure ports
$ java -jar wiremock-standalone-2.19.0.jar -- port 9090
Record & Map
$ java -jar wiremock-standalone-2.19.0.jar --proxy-all http://
wiremock.org —record-mappings
Review the mappings
http://localhost:8080/__admin/
Replay
$ java -jar wiremock-standalone-2.19.0.jar

42. ixchelruiz
Adding mappings (text/plain)
$ curl --verbose --data '{
"request": { "url": "/get/this", "method": "GET" },
"response": {
"status": 200, "body": "Here it is!n",
"headers": {"Content-Type": "text/plain"}
}}' http://localhost:8080/__admin/mappings/new
Test the new mapping
$ curl http://localhost:8080/get/this

43. ixchelruiz
Adding mappings (json)
$ curl --verbose --data '{
"request": { "url": "/get/json", "method": "GET" },
"response": {
"status": 200,
"jsonBody": {"unconferences":["jCrete","jAlba","jTaco"]},
"headers": {"Content-Type": "application/json"}
}}' http://localhost:8080/__admin/mappings/new
Test the new mapping
$ curl http://localhost:8080/get/json

44. ixchelruiz
Adding patterns in URLs
$ curl --verbose --data '{
"request": {
"urlPathPattern": "/get/([a-z]*)/test", "method": "GET" },
"response": {
"status": 200,
"body": "Here it is with pattern"
}}' http://localhost:8080/__admin/mappings/new
Test the new mapping
$ curl http://localhost:8080/get/whatever/test

45. ixchelruiz
Using patterns is the body
$ curl --verbose --data '{
"request": { "method": "POST", "url": "/post/bodyPattern",
"bodyPatterns" : [ {
"equalToJson" : { "total_results": 4 } }] },
"response": {
"status": 200, "body": "The body pattern was matched"
}}' http://localhost:8080/__admin/mappings/new
Test the new mapping
$ curl --verbose --data '{
"total_results":4}'
http://localhost:8080/post/bodyPattern

46. ixchelruiz
http://wiremock.org/docs/request-matching/

47. ixchelruiz
Delaying responses
$curl --verbose --data '{
"request": { "method": "GET", "url": "/get/delayed" },
"response": {
"status": 200,
"fixedDelayMilliseconds": 2000
}}' http://localhost:8080/__admin/mappings/new
Test the new mapping
$ curl http://localhost:8080/get/delayed

48. ixchelruiz
Simulating Fault
$curl --verbose --data '{
"request": {
"method": "GET", "url": "/get/fault"},
"response": {
"fault": "MALFORMED_RESPONSE_CHUNK"
}}' http://localhost:8080/__admin/mappings/new
Test the new mapping
$ curl http://localhost:8080/get/fault

49. ixchelruiz
Verifying number of requests
$ curl -X POST --header 'Content-Type: application/json'
--header 'Accept: application/json'
-d '{"url":"/get/delayed"}' 'http://localhost:8080/__admin/
requests/count'
Admin reference
http://localhost:8080/__admin/docs/
Reset
http://localhost:8080/__admin/reset/

50. ixchelruiz
https://chrome.google.com/webstore/detail/wiremock-extension/ikiaofdpbmofgmlhajfnhdjelkleljbl

51. ixchelruiz
REST
ASSURE

52. ixchelruiz
http://rest-assured.io

53. ixchelruiz

54. ixchelruiz
EXAMPLES

55. ixchelruiz
import static io.restassured.RestAssured.given;
import static io.restassured.RestAssured.get;
import static java.util.Arrays.asList;
import static org.hamcrest.Matchers.equalTo;
import org.junit.Test;
@Test
public void initial_data_is_loaded() {
given().
port(4567).
when().
get("/todos").
then().
body("todos.description", equalTo(asList(“Add Javadoc")));
}
@Test
public void formParamAreTreatedAsQueryParamsForGetRequests(){
given().
formParam("firstName", "John").
formParam("lastName", "Doe").
when().
get("/greet").
then().
body("greeting", equalTo("Greetings John Doe"));
}

56. ixchelruiz
import static io.restassured.RestAssured.given;
import static io.restassured.RestAssured.expect;
import static org.hamcrest.Matchers.equalTo;
import org.junit.Test;
@Test
public void newSyntaxWithCorrectStatusLineUsingStringMatching() {
expect().
statusLine("HTTP/1.1 200 OK").and().body("lotto.lottoId", equalTo(5)).
when().
get("/lotto");
}
@Test
public void requestSpecificationAllowsSpecifyingCookie() {
given().
cookie("username", “John”).then().
expect().
body(equalTo("username")).when().get("/cookie");
}
@Test
public void given_when_then_using_i18n_works() {
get(“/i18n").
then().
assertThat().body("ön", equalTo("Är ån"));
}

57. ixchelruiz
SPOCK

58. ixchelruiz
http://spockframework.org

59. ixchelruiz

60. ixchelruiz
EXAMPLES

61. ixchelruiz
@spock.lang.Unroll
class SampleControllerSpec extends spock.lang.Specification {
def "Invoke say hello with #input results in #output"() {
given:
SampleController controller = new SampleController()
controller.model = new SampleModel()
controller.service = Mock(SampleService) {
sayHello(input) >> output
}
when:
controller.model.input = input controller.sayHello()
then:
controller.model.output == output
where:
input << ['', 'Test']
output << ['Howdy, stranger!', 'Hello Test']
}
}

62. ixchelruiz
@spock.lang.Unroll
class SampleControllerSpec extends spock.lang.Specification {
def "Invoke say hello with #input results in #output"() {
given:
SampleController controller = new SampleController()
controller.model = new SampleModel()
controller.service = Mock(SampleService) {
sayHello(input) >> output
}
when:
controller.model.input = input
controller.sayHello()
then:
controller.model.output == output
where:
input | output
'' | 'Test'
'Howdy, stranger!' | 'Hello Test'
}
}

63. ixchelruiz
THANK YOU
FEEDBACK?