Software LEIC/LETI. Lecture 3

Transcription

1 Software LEIC/LETI Lecture 3

2 Last Lecture System Build Continuous Integration

3 Today Test Automation Verification and Validation Human Error, Fault, Error, Failure Verification vs Validation

4 Test automation

5 During builds we run tests, so we need a tool that help us to automate the testing

6 How can we test a system?

7 through the user interface How can we test a system?

8 through the user interface writing code in the main How can we test a system?

9 through the user interface writing code in the main DISADVANTAGES? How can we test a system?

10 Difficult to manage how to set the state of the system before the test? how to reset the effects of the test in the state after test execution?

11 Expensive to repeat need to interact again through the user interface rewrite the main method for each new test case

12 So, we need a tool

13 So, we need a tool - that stores the test cases

14 So, we need a tool - that stores the test cases - that sets and cleans the context of tests

15 JUnit

16 The tester focus on testing

17 The framework does the plumbing

18 for each test setup context run the test collect results clean the context present results

19 for each test setup context run the test never crashes! collect results clean the context present results

20 @Before public void setup() throws Exception { bank = new Bank( International ); public void deposit() { Account euaccount = new Account( João, EUR ); bank.addaccount(euaccount); euaccount.deposit(new Money(12, EUR )); } asserttrue(euaccount.getbalance().getvalue() == 12); assertequals( EUR, = IncorrectCurrencyException.class) public void depositinadifferentcurrency() { Account swaccount = new Account( Jean, CHF ); bank.addaccount(swaccount); } swaccount.deposit(new Money(12, EUR public void teardown() { for (Account account : bank.getaccounts()) { account.remove(); } bank.remove(); }

21 @Before public void setup() throws Exception { bank = new Bank( International ); } public void deposit() { Account euaccount = new Account( João, EUR ); bank.addaccount(euaccount); euaccount.deposit(new Money(12, EUR )); } asserttrue(euaccount.getbalance().getvalue() == 12); assertequals( EUR, = IncorrectCurrencyException.class) public void depositinadifferentcurrency() { Account swaccount = new Account( Jean, CHF ); bank.addaccount(swaccount); } swaccount.deposit(new Money(12, EUR public void teardown() { for (Account account : bank.getaccounts()) { account.remove(); } bank.remove(); }

22 @Before public void setup() throws Exception { bank = new Bank( International ); } public void deposit() { Account euaccount = new Account( João, EUR ); bank.addaccount(euaccount); euaccount.deposit(new Money(12, EUR )); run } asserttrue(euaccount.getbalance().getvalue() == 12); assertequals( EUR, = IncorrectCurrencyException.class) public void depositinadifferentcurrency() { Account swaccount = new Account( Jean, CHF ); bank.addaccount(swaccount); } swaccount.deposit(new Money(12, EUR public void teardown() { for (Account account : bank.getaccounts()) { account.remove(); } bank.remove(); }

23 @Before public void setup() throws Exception { bank = new Bank( International ); } public void deposit() { Account euaccount = new Account( João, EUR ); bank.addaccount(euaccount); euaccount.deposit(new Money(12, EUR )); run } asserttrue(euaccount.getbalance().getvalue() == 12); assertequals( EUR, = IncorrectCurrencyException.class) public void depositinadifferentcurrency() { Account swaccount = new Account( Jean, CHF ); bank.addaccount(swaccount); } swaccount.deposit(new Money(12, EUR public void teardown() { for (Account account : bank.getaccounts()) { account.remove(); } bank.remove(); } clean

24 @Before public void setup() throws Exception { bank = new Bank( International ); public void deposit() { Account euaccount = new Account( João, EUR ); bank.addaccount(euaccount); euaccount.deposit(new Money(12, EUR )); setup run setup } asserttrue(euaccount.getbalance().getvalue() == 12); assertequals( EUR, = IncorrectCurrencyException.class) public void depositinadifferentcurrency() { Account swaccount = new Account( Jean, CHF ); bank.addaccount(swaccount); } swaccount.deposit(new Money(12, EUR public void teardown() { for (Account account : bank.getaccounts()) { account.remove(); } bank.remove(); } clean

25 @Before public void setup() throws Exception { bank = new Bank( International ); public void deposit() { Account euaccount = new Account( João, EUR ); bank.addaccount(euaccount); euaccount.deposit(new Money(12, EUR )); setup run setup } asserttrue(euaccount.getbalance().getvalue() == 12); assertequals( EUR, = IncorrectCurrencyException.class) public void depositinadifferentcurrency() { Account swaccount = new Account( Jean, CHF ); bank.addaccount(swaccount); run } swaccount.deposit(new Money(12, EUR public void teardown() { for (Account account : bank.getaccounts()) { account.remove(); } bank.remove(); } clean

26 @Before public void setup() throws Exception { bank = new Bank( International ); public void deposit() { Account euaccount = new Account( João, EUR ); bank.addaccount(euaccount); euaccount.deposit(new Money(12, EUR )); setup run setup } asserttrue(euaccount.getbalance().getvalue() == 12); assertequals( EUR, = IncorrectCurrencyException.class) public void depositinadifferentcurrency() { Account swaccount = new Account( Jean, CHF ); bank.addaccount(swaccount); run } swaccount.deposit(new Money(12, EUR public void teardown() { for (Account account : bank.getaccounts()) { account.remove(); } bank.remove(); } clean clean

27 In the cases that an exception occurs we may want to verify that the state didn't change

28 @Test(expected = IncorrectCurrencyException.class) public void deposit() { Account swaccount = new Account( Jean, CHF ); bank.addaccount(swaccount); } swaccount.deposit(new Money(12, EUR ));

29 @Test(expected = IncorrectCurrencyException.class) public void deposit() { Account swaccount = new Account( Jean, CHF ); bank.addaccount(swaccount); } swaccount.deposit(new Money(12, EUR )); vs

30 @Test(expected = IncorrectCurrencyException.class) public void deposit() { Account swaccount = new Account( Jean, CHF ); bank.addaccount(swaccount); } swaccount.deposit(new Money(12, EUR )); public void deposit() { Account swaccount = new Account( Jean, CHF ); bank.addaccount(swaccount); } try { swaccount.deposit(new Money(12, EUR )); fail(); } catch(incorrectcurrencyexception e) { assertequals(0, swaccount.getbalance()); }

31 Tests in the project

32 two different trees that share the same naming structure

33 Bank Module * Operation 1 String reference OperationType type int value DateTime time 1 Bank * String code String name 1 Client String ID String name 1 * * Account String IBAN int balance

34

35 pt.ulisboa.tecnico.softeng.bank.domain

36 pt.ulisboa.tecnico.softeng.bank.domain one test class for each method

37

38

39 easier to show the code using eclipse

40 Activity Module ActivityProvider 1 * Activity 1 * ActivityOffer 1 * Booking String name String code String name String code int minage int maxage int capacity LocalDate begin LocalDate end int capacity String reference

41 let s show the code using eclipse

42 Hotel Module Hotel 1 * Room 1 * Booking String code String name String number RoomType type String reference LocalDate arrival LocalDate departure

43 let s show the code using eclipse

44 Broker Module Broker String code Sting name 1 * Adventure String ID LocalDate begin LocalDate end int age String IBAN int amount String bankpayment String roombooking String activitybooking 1 1 AdventureState int raeerrors InitialState PayedState ConfirmedState CanceledState

45 let s show the code using eclipse

46 Software Testing To Err is Human

47 Software has bugs!

48 Why?

49 Why?

50 To err is human

51 Humans write software

52 Computers execute software

53 Human Error

54 Human Error creates

55 Human Error creates Fault

56 Human Error creates Fault generates

57 Human Error creates Fault generates Error

58 Human Error creates Fault generates Error... generates more errors

59 Human Error creates Fault generates Error... generates more errors Failure

60 Human Error creates Fault generates Identify faults Error... generates more errors Failure

61 Human Error creates Fault Identify faults generates Error D I S T... generates more errors A N C E Failure

62 Human Error creates Fault Identify faults generates Error D I S T Time since it was created... generates more errors A N C E Failure

63 Human Error creates Fault generates D Time since it I was created Error S Identify faults T A... generates more errors N C Number of errors before E failure Failure

64 Failure

65 Failure... identify

66 Failure... identify Fault

67 Failure... identify Fault

68 Failure... identify Fault cause

69 Failure... identify Fault cause Human Error

70 Failure... identify Fault cause Human Error

71 Failure... identify Fault cause Human Error infer more

72 Failure... identify Fault cause Human Error infer more Fault

73 Failure... identify Identify the cause of bugs Fault cause Human Error infer more Fault

74 Failure... identify Identify the cause of bugs Fault cause Human Error infer more Fault It helps to identify other faults that have the same cause

75

76 Human Error - an human action which produces software faults

77 Human Error - an human action which produces software faults Fault - an omission, a defect, in the software cause of a human error

78 Human Error - an human action which produces software faults Fault - an omission, a defect, in the software cause of a human error Error - an unexpected change in the system behaviour caused by a fault

79 Human Error - an human action which produces software faults Fault - an omission, a defect, in the software cause of a human error Error - an unexpected change in the system behaviour caused by a fault Failure - an observable error

80 Is it a bug or a feature?

81 Did we build the right product?

82 Did we build the product right?

83 back to basics...

84 Software is language

85 How can we write the right product?

86 problem specification vs client needs

87 Verification - we did it right, according to the specification

88 Validation - we did it according to the client needs

89 Developer

90 Developer builds according to the specification

91 Developer builds according to the specification Software System

92 Developer builds according to the specification Software System Client

93 Developer builds according to the specification Software System uses according to their needs Client

94 Developer builds according to the specification Software System may be a mismatch uses according to their needs Client

95 Software System

96 Software System tests according to the specification

97 Software System tests according to the specification Developer (tester)

98 Software System tests according to the specification tests according to their needs Developer (tester)

99 Software System tests according to the specification tests according to their needs Developer Client (tester)

100 There is a mismatch between the problem specification and the client needs language transformations

101 How can we solve this mismatch?

102 Work with the client there is no problem specification less transformations

103 Is it always possible? if we do not have a client in the team

104 Have precise specifications small transformations

105 So is it a bug or a feature?

106 What can I test?

107 source code

108 source code requirement documents

109 source code requirement documents models

110 source code requirement documents models solution specifications

111 source code requirement documents... models solution specifications

112 source code requirement documents... models solution specifications Tests, reviews, inspections,

113

114 All software development artefacts!

115 How do I test?

116 As a mathematician

117 Prove that the software is correct

118 It is driven by the specification

119 As an accountant

120 Inspect the software

121 It is driven by experience and standards

122 as an engineer

123 run the software enough times

124 When is enough, enough?

125 Both, static (reviews and inspections) and dynamic (tests) verification and validation is important!

126 When should we apply each technique?

127 Reviews and Inspections can be applied to all descriptions humans are good at reading descriptions

128 Tests runtime behaviour of the system computers are good at executing descriptions