Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
SOME
TESTING
The miseries and great
hardships of software testing
Sergio Arroyo Cuevas - @delr3ves
“I get paid for code that works, not for tests, so
my philosophy is to test as little as possible to
reach a given level o...
WHO AM I?
WHO AM I?
MOTIVATION
DISCLAIMER
No silver bullets
What is testing about?
Getting feedback,
as often as we can
the sooner, the better
So please, send me your’s
@delr3ves
WHAT ARE WE TALKING ABOUT?
TAXONOMY
Taxonomy	
Scope	
Unit	
Integra3on	
System	
Visibillity	
Black	box	
White	box	
Inten3on	
Acceptance	
Func3onal	
Non	Func3on...
TESTS BY SCOPE
SCOPE
Database
PORT1 PORT2
ADAPTER1
UNIT TEST
DEPENDENCY INJECTION
➤Dependency:

A depends on B when A needs B to do
its job.
➤Injection:

Object (C) which uses A will ...
DEPENDENCY INJECTION
➤Dependency:

A depends on B when A needs B to do
its job.
➤Injection:

Object (C) which uses A will ...
DEPENDENCY INJECTION
C
A
B
➤A depends on B
➤C will tell A who is C
DEPENDENCY INJECTION
➤ Separate business logic from creation logic
➤Avoid use of new for service objects.
➤Value objects c...
DEPENDENCY INJECTION
public UserService(UserValidator userValidator, UserDao userDao) {
this.userValidator = userValidator...
DEPENDENCY INJECTION
public UserService(UserValidator userValidator, UserDao userDao) {
this.userValidator = userValidator...
TEST DOUBLES
TEST DOUBLES (FAKE)
Fake implementation in order to make test pass.
public UserDaoFake implements UserDao {
public User cr...
TEST DOUBLES (STUB)
Stubs provide canned answers to calls made during the test,
usually not responding at all to anything ...
TEST DOUBLES (SPY)
Spies are objects that also record some information based on how
they were called
var validatorSpy = Si...
TEST DOUBLES (SPY)
Spies are objects that also record some information based on how
they were called
var validatorSpy = Si...
TEST DOUBLES (MOCKS)
Informal: think in a Stub which is also a Spy.
It also responds with default values to non-explicitly...
INTEGRATION TEST WHICH WANT TO BE UNIT TESTS
FIRST(IT)
➤ Fast
➤Hundreds or thousands per second
➤ Isolates
➤Failure reasons become obvious
➤ Repeatable
➤In any order, ...
INTEGRATION TEST WHICH WORKS WITH EXTERNAL SYSTEM
Database
Fast
Isolates
Repeatable
Self-Validating
Timely
Inmutable*
Trus...
INTEGRATION TEST WHICH WORKS WITH EXTERNAL SYSTEM
Database
Fast
Isolates
Repeatable
Self-Validating
Timely
Inmutable*
Trus...
INTEGRATION TEST WHICH USES THE UI
Database
Fast
Isolates
Repeatable
Self-Validating
Timely
Inmutable*
Trusted*
INTEGRATION TEST WHICH USES THE UI
Database
Fast
Isolates
Repeatable
Self-Validating
Timely
Inmutable*
Trusted*
SYSTEM TEST
Database
Fast
Isolates
Repeatable
Self-Validating
Timely
Inmutable*
Trusted*
SYSTEM TEST
Database
Fast
Isolates
Repeatable
Self-Validating
Timely
Inmutable*
Trusted*
WHO, WHEN AND WHERE RUN THE TESTS?
➤ Unit
➤ Owner: developer
➤ When: after every change
➤ Where: every computer
➤ Integrat...
STRATEGIES
STATIC EVALUATION
➤Informal review
➤Formal review (inspection)
➤Checklists
➤Successive abstraction
➤Walkthrough
DYNAMIC EVALUATION
➤White box
➤Path Coverage
➤Statement Coverage
➤Condition Coverage
➤Function Coverage
➤Black box
➤Equiva...
WHITE BOX (*-COVERAGE)
1. Get flow diagram of the SUT
2. Calculate cyclomatic complexity

3. Determine a data set which for...
WHITE BOX (*-COVERAGE)
1. Get flow diagram of the SUT
2. Calculate cyclomatic complexity

3. Determine a data set which for...
WHITE BOX (*-COVERAGE)
1. Get flow diagram of the SUT
2. Calculate cyclomatic complexity

3. Determine a data set which for...
BLACK BOX (PARTITIONING)
1. Identify equivalence classes
2. Select dataset:
1. Assign a unique value for every class
2. Se...
BLACK BOX (PARTITIONING)
1. Identify equivalence classes
2. Select dataset:
1. Assign a unique value for every class
2. Se...
BLACK BOX (PARTITIONING)
1. Identify equivalence classes
2. Select dataset:
1. Assign a unique value for every class
2. Se...
BLACK BOX (PARTITIONING)
Register
Username*
Password (6-10 chars including numbers)
BLACK BOX (PARTITIONING)
Username Password
U1: myNick P1: p4ssw0rd
U2: “empty” P2: p4ss
P3: l4rg3p4ssw0rd
P4: password
Reg...
BLACK BOX (PARTITIONING)
Username Password
U1: myNick P1: p4ssw0rd
U2: “empty” P2: p4ss
P3: l4rg3p4ssw0rd
P4: password
Reg...
BLACK BOX (METHODS WHICH TELL US A STORY)
VS
BLACK BOX (METHODS WHICH TELL US A STORY)
but if you hate exceptions…
AUTOMATIC TESTING
4 PHASES-TESTS
1. Set Up
2. Exercise
3. Verify
4. TearDown
TESTING FRAMEWORKS FAMILIES
➤X-Unit
➤@Before(Class)
➤@Test
➤@After(Class)
➤Spec
➤describe
➤ beforeEach
➤ it
➤ afterEach
➤S...
XUNIT
@Before
public void setUp() {
this.userValidator = mock(UserValidator.class);
this.userDao = mock(UserDao.class);
th...
SPEC (SUITE PER CLASS)
describe('UserService test suite:', function(){
beforeEach(function(){
// setup the SUT
})
it('when...
SPEC (SUITE PER SETUP)
describe('UserService test suite:', function(){
describe("when create a valid user ", function() {
...
BDD (SPECIFICATION)
Feature: User registration
Scenario: User tries to register sending valid data so the system will crea...
BDD(IMPLEMENTATION)
@given("the user has introduced (w)+ and (w)+ into the
registration form")
public void populateForm(St...
TESTABLE DESIGN
NON-TESTABLE DESIGN SMELLS (BY MISKO HEVERY*)
➤Constructor does Real Work
➤Mixing business and creation logic
➤Class does ...
FROMNON-TESTABLETOTESTABLE
➤First of all, go to http://refactoring.com/
➤I suggest:
1. Add integration regression test.
2....
REMOVES NEW FOR DEPENDENCIES
public UserService() {
this(new UserValidator(), new UserDao());
}
public UserService(UserVal...
ADD FACTORIES FOR STATEFUL DEPENDENCIES
public UserService() {
this(new UserValidatorFactory(), new UserDao());
}
public U...
REMOVE STATIC CLASSES AND METHODS
class MyJsonSerializer {
public static String serialize(Object myObject) {
//put your ma...
REMOVE STATIC CLASSES AND METHODS
class MysonSerializer {
public String serialize(Object myObject) {
//put your magic here...
TIPS & TRICKS
QUESTIONS & STUPID QUESTIONS
➤I spend more time writing code to setup my SUT than
writing the test, how do you solve it?
➤...
ISPENDMORETIMEWRITINGCODETOSETUPMYSUTTHANWRITINGTHETEST,HOWDOYOUSOLVEIT?
➤Read about Fixtures (Xunit Patterns is a
good re...
IDUPLICATETOOMUCHCODEONOBJECTSCREATION,MOCKSDEFINITIONANDASSERTION…
➤Writing a lot of code to initialize value objects?
➤C...
I’VENEVERWRITEATEST,WHERECANISTART?
I’ll bet you a beer that
you called it *[Util|
Helper]…
Database
PORT1 PORT2
ADAPTER1
SHOULD I VERIFY EVERY SINGLE INTERACTION WITH MY MOCKS?
It depends
But if you feel you have to, it’s probably due
to a bad...
WHO TESTS THE CLASSES WHICH TEST OUR CLASSES?
➤Exactly, this is why it’s so important our tests follow
KISS
Q&A
Place your question here!
@delr3ves
WHERE I PLACE MY TESTS?
➤Unit tests:
➤Test Class per Class
➤Test Class per SetUp (useful in Xunit frameworks)
➤Important n...
WHERE I PLACE MY TESTS?
Java Project (Test Class per Class)
MyProject/
src/
main/
java/
com.groupId.artifactId.MyClass.jav...
WHERE I PLACE MY TESTS?
IOS Project
MyIOSProject/
MyIOSProject/
... app code ...
MyIOSProjectTests/
... test code ...
Andr...
¿COULDYOUBEABLETOREWRITETHECODEONLYREADINGTHETESTSDEFINITIONS?

➤Tests (specially Black Box tests) should tell us an story...
WHAT IS THE MINIMUM CODE COVERAGE?
➤“… test as little as possible to reach a given level of
confidence …”
➤Do not get obses...
Q&A
Place your question here!
@delr3ves
#codemotion2016: Everything you should know about testing to go with @pedro_g_s, @flipper83 & @kinisoftware avoiding the h...
#codemotion2016: Everything you should know about testing to go with @pedro_g_s, @flipper83 & @kinisoftware avoiding the h...
#codemotion2016: Everything you should know about testing to go with @pedro_g_s, @flipper83 & @kinisoftware avoiding the h...
Upcoming SlideShare
Loading in …5
×

#codemotion2016: Everything you should know about testing to go with @pedro_g_s, @flipper83 & @kinisoftware avoiding the hangover

581 views

Published on

Slides used in my talk in #Codemotion2016

Published in: Software
  • Be the first to comment

  • Be the first to like this

#codemotion2016: Everything you should know about testing to go with @pedro_g_s, @flipper83 & @kinisoftware avoiding the hangover

  1. 1. SOME TESTING The miseries and great hardships of software testing Sergio Arroyo Cuevas - @delr3ves
  2. 2. “I get paid for code that works, not for tests, so my philosophy is to test as little as possible to reach a given level of confidence … -Kent Beck
  3. 3. WHO AM I?
  4. 4. WHO AM I?
  5. 5. MOTIVATION
  6. 6. DISCLAIMER
  7. 7. No silver bullets
  8. 8. What is testing about?
  9. 9. Getting feedback, as often as we can
  10. 10. the sooner, the better
  11. 11. So please, send me your’s @delr3ves
  12. 12. WHAT ARE WE TALKING ABOUT?
  13. 13. TAXONOMY
  14. 14. Taxonomy Scope Unit Integra3on System Visibillity Black box White box Inten3on Acceptance Func3onal Non Func3onal … Technique Sta3c Dynamic Execu3on Automa3c Manual Google’s Small Medium Big
  15. 15. TESTS BY SCOPE
  16. 16. SCOPE Database PORT1 PORT2 ADAPTER1
  17. 17. UNIT TEST
  18. 18. DEPENDENCY INJECTION ➤Dependency:
 A depends on B when A needs B to do its job. ➤Injection:
 Object (C) which uses A will tell A who is B.
  19. 19. DEPENDENCY INJECTION ➤Dependency:
 A depends on B when A needs B to do its job. ➤Injection:
 Object (C) which uses A will tell A who is B.
  20. 20. DEPENDENCY INJECTION C A B ➤A depends on B ➤C will tell A who is C
  21. 21. DEPENDENCY INJECTION ➤ Separate business logic from creation logic ➤Avoid use of new for service objects. ➤Value objects can be created any where. ➤ Service objects in charge to implement business logic. ➤ IOC Container or factories in charge of creation logic.
  22. 22. DEPENDENCY INJECTION public UserService(UserValidator userValidator, UserDao userDao) { this.userValidator = userValidator; this.userDao = userDao; } public User createUser(User user) throws ValidationException { this.userValidator.validate(user); user = this.userDao.create(user); return user; } public User createUser(User user) throws ValidationException { UserValidator userValidator = new UserValidator(...); userValidator.validate(user); UserDao userDao = new UserDao(...); user = userDao.create(user); return user; } VS
  23. 23. DEPENDENCY INJECTION public UserService(UserValidator userValidator, UserDao userDao) { this.userValidator = userValidator; this.userDao = userDao; } public User createUser(User user) throws ValidationException { this.userValidator.validate(user); user = this.userDao.create(user); return user; } public User createUser(User user) throws ValidationException { UserValidator userValidator = new UserValidator(...); userValidator.validate(user); UserDao userDao = new UserDao(...); user = userDao.create(user); return user; } VS this sucks
  24. 24. TEST DOUBLES
  25. 25. TEST DOUBLES (FAKE) Fake implementation in order to make test pass. public UserDaoFake implements UserDao { public User create(User user) { return ...; } }
  26. 26. TEST DOUBLES (STUB) Stubs provide canned answers to calls made during the test, usually not responding at all to anything outside what’s programmed in for the test. UserValidator validatorMock = mock(UserValidator.class); stub(validatorMock.validate(any(User.class))) .toThrow(new ValidationException()); var validateCall = Sinon.stub(); validatorStub.withArgs(user) .onFirstCall().returns(validationError); var userValidator = { validate: validatorStub; } OR WITH JS
  27. 27. TEST DOUBLES (SPY) Spies are objects that also record some information based on how they were called var validatorSpy = Sinon.spy(); var userValidator = { validate: validatorSpy; } userValidator.validate(user); sinon.assert.calledOnce(validatorSpy); sinon.assert.calledWith(validatorSpy, user); OR WITH JS UserValidator validatorSpy = spy(new UserValidator()); doThrow(new ValidationException()) .when(validatorSpy).validate();
  28. 28. TEST DOUBLES (SPY) Spies are objects that also record some information based on how they were called var validatorSpy = Sinon.spy(); var userValidator = { validate: validatorSpy; } userValidator.validate(user); sinon.assert.calledOnce(validatorSpy); sinon.assert.calledWith(validatorSpy, user); OR WITH JS UserValidator validatorSpy = spy(new UserValidator()); doThrow(new ValidationException()) .when(validatorSpy).validate();
  29. 29. TEST DOUBLES (MOCKS) Informal: think in a Stub which is also a Spy. It also responds with default values to non-explicitly declared methods UserValidator validatorMock = mock(UserValidator.class); when(validatorMock.validate(any(User.class))) .thenTrhow(new ValidationException()); verify(validatorMock).validate(any(User.class)) var validatorAPI = {validate: function()}; var validatorMock = Sinon.mock(validatorAPI); validatorMock.expects('validate').once() .withArgs(user).throws(validationError) validatorAPI.validate(user) validatorMock.verify() OR WITH JS
  30. 30. INTEGRATION TEST WHICH WANT TO BE UNIT TESTS
  31. 31. FIRST(IT) ➤ Fast ➤Hundreds or thousands per second ➤ Isolates ➤Failure reasons become obvious ➤ Repeatable ➤In any order, any time ➤ Self-validating ➤No manual execution required ➤ Timely ➤Written before code ➤ Immutable* ➤SUT is in the same state after execute the tests ➤ Trusted* ➤When the test fails, the system fail and when the test works, the system works
  32. 32. INTEGRATION TEST WHICH WORKS WITH EXTERNAL SYSTEM Database Fast Isolates Repeatable Self-Validating Timely Inmutable* Trusted*
  33. 33. INTEGRATION TEST WHICH WORKS WITH EXTERNAL SYSTEM Database Fast Isolates Repeatable Self-Validating Timely Inmutable* Trusted*
  34. 34. INTEGRATION TEST WHICH USES THE UI Database Fast Isolates Repeatable Self-Validating Timely Inmutable* Trusted*
  35. 35. INTEGRATION TEST WHICH USES THE UI Database Fast Isolates Repeatable Self-Validating Timely Inmutable* Trusted*
  36. 36. SYSTEM TEST Database Fast Isolates Repeatable Self-Validating Timely Inmutable* Trusted*
  37. 37. SYSTEM TEST Database Fast Isolates Repeatable Self-Validating Timely Inmutable* Trusted*
  38. 38. WHO, WHEN AND WHERE RUN THE TESTS? ➤ Unit ➤ Owner: developer ➤ When: after every change ➤ Where: every computer ➤ Integration ➤ Owner: developer || QA team ➤ When: as part or after commit stage ➤ Where: devel and pre-pro environments ➤ System ➤ Owner: QA team ➤ When: after commit stage ➤ Where: devel and pre-pro environments
  39. 39. STRATEGIES
  40. 40. STATIC EVALUATION ➤Informal review ➤Formal review (inspection) ➤Checklists ➤Successive abstraction ➤Walkthrough
  41. 41. DYNAMIC EVALUATION ➤White box ➤Path Coverage ➤Statement Coverage ➤Condition Coverage ➤Function Coverage ➤Black box ➤Equivalence partitioning ➤Boundary values analysis
  42. 42. WHITE BOX (*-COVERAGE) 1. Get flow diagram of the SUT 2. Calculate cyclomatic complexity
 3. Determine a data set which force going one path or another 4. Exercise the SUT with this dataset. errors = [] if(user.name ==null||user.email == null) { errors.push('mandatory fields not found'); } //do the rest of whatever for(var i=0; i < user.friends ; i++ ) { errors.push(checkFriendShipt(user.friends[i])) }
  43. 43. WHITE BOX (*-COVERAGE) 1. Get flow diagram of the SUT 2. Calculate cyclomatic complexity
 3. Determine a data set which force going one path or another 4. Exercise the SUT with this dataset. errors = [] if(user.name ==null||user.email == null) { errors.push('mandatory fields not found'); } //do the rest of whatever for(var i=0; i < user.friends ; i++ ) { errors.push(checkFriendShipt(user.friends[i])) } a b c d …x
  44. 44. WHITE BOX (*-COVERAGE) 1. Get flow diagram of the SUT 2. Calculate cyclomatic complexity
 3. Determine a data set which force going one path or another 4. Exercise the SUT with this dataset. errors = [] if(user.name ==null||user.email == null) { errors.push('mandatory fields not found'); } //do the rest of whatever for(var i=0; i < user.friends ; i++ ) { errors.push(checkFriendShipt(user.friends[i])) } a b c d …x edges – nodes + 2 = predicate nodes +1 = number of regions = 4
  45. 45. BLACK BOX (PARTITIONING) 1. Identify equivalence classes 2. Select dataset: 1. Assign a unique value for every class 2. Select tests cases which cover the most valid classes 3. Select tests cases which cover only one invalid class at the same time
  46. 46. BLACK BOX (PARTITIONING) 1. Identify equivalence classes 2. Select dataset: 1. Assign a unique value for every class 2. Select tests cases which cover the most valid classes 3. Select tests cases which cover only one invalid class at the same time
  47. 47. BLACK BOX (PARTITIONING) 1. Identify equivalence classes 2. Select dataset: 1. Assign a unique value for every class 2. Select tests cases which cover the most valid classes 3. Select tests cases which cover only one invalid class at the same time
  48. 48. BLACK BOX (PARTITIONING) Register Username* Password (6-10 chars including numbers)
  49. 49. BLACK BOX (PARTITIONING) Username Password U1: myNick P1: p4ssw0rd U2: “empty” P2: p4ss P3: l4rg3p4ssw0rd P4: password Register Username* Password (6-10 chars including numbers)
  50. 50. BLACK BOX (PARTITIONING) Username Password U1: myNick P1: p4ssw0rd U2: “empty” P2: p4ss P3: l4rg3p4ssw0rd P4: password Register Username* Password (6-10 chars including numbers) Test Cases myNick, p4ssw0rd √ myNick, p4ss X myNick, l4rg3p4ssw0rd X myNick, password X “empty”, p4ssw0rd X myNick, p4sw0rd_* X
  51. 51. BLACK BOX (METHODS WHICH TELL US A STORY) VS
  52. 52. BLACK BOX (METHODS WHICH TELL US A STORY) but if you hate exceptions…
  53. 53. AUTOMATIC TESTING
  54. 54. 4 PHASES-TESTS 1. Set Up 2. Exercise 3. Verify 4. TearDown
  55. 55. TESTING FRAMEWORKS FAMILIES ➤X-Unit ➤@Before(Class) ➤@Test ➤@After(Class) ➤Spec ➤describe ➤ beforeEach ➤ it ➤ afterEach ➤Specification by example (A.K.A BDD) ➤Given ➤When ➤Then
  56. 56. XUNIT @Before public void setUp() { this.userValidator = mock(UserValidator.class); this.userDao = mock(UserDao.class); this.userService = new UserService(userValidator, userDao); } @Test public void createValidUserShouldNotFail() { //Exercise User expectedCreatedUser = new User("irrelevantUser"); when(userValidator.validate(any(User.class))); when(userValidator.validate(any(User.class))).thenReturn(createdUser); User createdUser = userService.create(new User()); //Assertions assertThat(createdUser, equalTo(expectedCreatedUser)); } @Test(expected=ValidationException) public void createInvalidUserShouldFail() { when(userValidator.validate(any(User.class))) .thenReturn(new ValidationException()); userService.create(new User("irrelevantUser")); } @After public void tearDown() { //clean the state here }
  57. 57. SPEC (SUITE PER CLASS) describe('UserService test suite:', function(){ beforeEach(function(){ // setup the SUT }) it('when create a valid user should not fail', function(){ // exercise + assertions }) it('when create an invalid user should fail', function(){ // exercise + assertions }) afterEach(function(){ // clean the state }) }) • UserService test suite: • When create a valid user should not fail √ • When create an invalid user should fail √ The report will look like:
  58. 58. SPEC (SUITE PER SETUP) describe('UserService test suite:', function(){ describe("when create a valid user ", function() { beforeEach(function(){ // setup and exercise }) it('should return valid user', function(){ // partial assertions }) it('should call validator', function(){ // partial assertions }) it('should call dao', function(){ // partial assertions }) afterEach(function(){ // clean the state }) }) })
  59. 59. BDD (SPECIFICATION) Feature: User registration Scenario: User tries to register sending valid data so the system will create new account Given the user has introduced <username> and <password> into the registration form And has accepted terms and agreements When send the registration from Then the user with <username> should be created Example: | username | password | | myNick | p4ssw0rd | Scenario: User tries to register sending invalid data so the system will reject user Given the user has introduced <username> and <password> into the registration form And has accepted terms and agreements When send the registration from Then the system should notify <error> Example: | username | password | error | | myNick | p4ss | password should have at least 6 characters | | myNick | l4rg3p4ssword | password should have at less than 10 characters | | myNick | password | password should contains at least a number | | | p4ssword | username is mandatory |
  60. 60. BDD(IMPLEMENTATION) @given("the user has introduced (w)+ and (w)+ into the registration form") public void populateForm(String username, String password) { ... } @given("has accepted terms and agreements") public void acceptTerms() { ... } @when("send the registration from") public void sendRegistrationForm() { ... } @then("the user with (w)+ should be created") public void verifyUserIsCreated(String username) { ... } @then("the system should notify <error>") public void verifyErrors(String error) { ... }
  61. 61. TESTABLE DESIGN
  62. 62. NON-TESTABLE DESIGN SMELLS (BY MISKO HEVERY*) ➤Constructor does Real Work ➤Mixing business and creation logic ➤Class does too much work ➤Digging into collaborations ➤Brittle Global State & Singletons *See http://misko.hevery.com/attachments/Guide-Writing Testable Code.pdf
  63. 63. FROMNON-TESTABLETOTESTABLE ➤First of all, go to http://refactoring.com/ ➤I suggest: 1. Add integration regression test. 2. Remove new from methods and ad it to constructors (this will prepare your class for dependency injection). 3. Add a factory for Stateful services 4. Creates a constructor which receive every dependency your class will need. 5. Remove static classes and methods (adding the new non-static as a class dependency). 6. Add as much tests as you want to ;) ➤Important!!! Do it step by step
  64. 64. REMOVES NEW FOR DEPENDENCIES public UserService() { this(new UserValidator(), new UserDao()); } public UserService(UserValidator userValidator, UserDao userDao) { this.userValidator = userValidator; this.userDao = userDao; } public User createUser(User user) throws ValidationException { this.userValidator.validate(user); user = this.userDao.create(user); return user; } public User createUser(User user) throws ValidationException { UserValidator userValidator = new UserValidator(...); userValidator.validate(user); UserDao userDao = new UserDao(...); user = userDao.create(user); return user; } TO
  65. 65. ADD FACTORIES FOR STATEFUL DEPENDENCIES public UserService() { this(new UserValidatorFactory(), new UserDao()); } public UserService(UserValidator userValidatorFactory, UserDao userDao) { this.userValidatorFactory = userValidatorFactory; this.userDao = userDao; } public User createUser(User user) throws ValidationException { this.userValidatorFactory.getInstance(user).validate(); ... } public User createUser(User user) throws ValidationException { UserValidator userValidator = new UserValidator(user); userValidator.validate(); ... } TO
  66. 66. REMOVE STATIC CLASSES AND METHODS class MyJsonSerializer { public static String serialize(Object myObject) { //put your magic here } } class UserClient { public void createUser(User user) { Http.post(url, JsonSerizalizer.serialize(user)); } }
  67. 67. REMOVE STATIC CLASSES AND METHODS class MysonSerializer { public String serialize(Object myObject) { //put your magic here } } class HttpClientWrapper { public void post(String url, String body) { Http.post(url, body); } } class UserClient { private JsonSerializer serializer; private HttpClientWrapper httpClient public UserClient() { serializer = new JsonSerializer(); httpClient = new HttpClientWrapper(); } public void createUser(User user) { httpClient.post(url, serializer.serialize(user)); } }
  68. 68. TIPS & TRICKS
  69. 69. QUESTIONS & STUPID QUESTIONS ➤I spend more time writing code to setup my SUT than writing the test, how do you solve it? ➤I’ve never write a test, where can I start? ➤Should I verify every single interaction with my mocks? ➤Who tests the classes which test our classes? ➤Where I place my tests? ➤Could you be able to rewrite the code only reading the tests definitions? ➤What is the minimum coverage should I expect for my code?
  70. 70. ISPENDMORETIMEWRITINGCODETOSETUPMYSUTTHANWRITINGTHETEST,HOWDOYOUSOLVEIT? ➤Read about Fixtures (Xunit Patterns is a good reference). ➤Fresh fixtures ➤Shared fixtures ➤Persistent fixtures ➤Think about new ways of organising your tests.
  71. 71. IDUPLICATETOOMUCHCODEONOBJECTSCREATION,MOCKSDEFINITIONANDASSERTION… ➤Writing a lot of code to initialize value objects? ➤Create DataBuilders / MotherObjects ➤Writing a lot of code to initialize mock/stub objects? ➤Create Mock“Mother” ➤Writing a lot of asserts (TDD purist says only one assertion)? ➤Create CustomAsserts User user = new User("irrelevantUsername", "v4l1dP4ss", irrelevant@myCompany.com", ...); VS User user = userMother.createValidUser(); assertNotNull(user.getUsername()); assertNotNull(user.getPassword()); assertNotNull(user.getEmail()); ... VS assertContainsAllMandatoryData(user);
  72. 72. I’VENEVERWRITEATEST,WHERECANISTART? I’ll bet you a beer that you called it *[Util| Helper]… Database PORT1 PORT2 ADAPTER1
  73. 73. SHOULD I VERIFY EVERY SINGLE INTERACTION WITH MY MOCKS? It depends But if you feel you have to, it’s probably due to a bad design :S
  74. 74. WHO TESTS THE CLASSES WHICH TEST OUR CLASSES? ➤Exactly, this is why it’s so important our tests follow KISS
  75. 75. Q&A Place your question here! @delr3ves
  76. 76. WHERE I PLACE MY TESTS? ➤Unit tests: ➤Test Class per Class ➤Test Class per SetUp (useful in Xunit frameworks) ➤Important naming convention (<ClassName>Test, <TestSuite>IntegrationTest, …) ➤System tests: ➤Different project
  77. 77. WHERE I PLACE MY TESTS? Java Project (Test Class per Class) MyProject/ src/ main/ java/ com.groupId.artifactId.MyClass.java resources/ test/ java/ com.groupId.artifactId.MyClassTest.java com.groupId.artifactId.it.suite.MyTestCaseIntegrationTest.java resources/ NodeJs Project MyProject/ lib/ myClass.js main.js test/ ut/ /suite it/ lib/ myClassTest.js Java Project (Class per SetUp) MyProject/ src/ main/ … test/ java/ com.groupId.artifactId.myclass.<SetUp1>Test.java com.groupId.artifactId.myclass.<SetUp2>Test.java …
  78. 78. WHERE I PLACE MY TESTS? IOS Project MyIOSProject/ MyIOSProject/ ... app code ... MyIOSProjectTests/ ... test code ... Android Project MyProject/ AndroidManifest.xml res/ ... (resources for main application) src/ main/ … (source code for main application) … test/ … (unit tests) … androidTest/ … (android specific tests / UI, etc) … tests/ AndroidManifest.xml res/ … (resources for tests) src/ ... (source code for tests)
  79. 79. ¿COULDYOUBEABLETOREWRITETHECODEONLYREADINGTHETESTSDEFINITIONS?
 ➤Tests (specially Black Box tests) should tell us an story. ➤Use well defined, and complete scenarios for system tests: ➤Use business vocabulary for acceptance tests: public void testValidaterUser1 { ... } VS public void validate_user_with_no_password_should_throws_error { ... } com.mycompany.artifactId.it.TestSteps ... VS com.mycompany.artifactId.it.usermanagement.UserCreationSteps ...
  80. 80. WHAT IS THE MINIMUM CODE COVERAGE? ➤“… test as little as possible to reach a given level of confidence …” ➤Do not get obsess over test coverage, it’s a metric, not a goal. It depends
  81. 81. Q&A Place your question here! @delr3ves

×