1. Avatars of TDD
Rule of Diversity
Distrust all claims for
“One True Way”
Naresh Jain
naresh@agilefaqs.com
@nashjain
http://nareshjain.com
Copyright © 2013, AgileFAQs. All Rights Reserved.

2. Key Questions
Business Facing
Are we building the right product?
Are we building the product right?
Technology/Implementation Facing
Copyright © 2013, AgileFAQs. All Rights Reserved.

3. Brian Marick’s Test Categorization
Before/While Coding Post Coding
Business Facing
Supports Programming
Critique product
Technology/Implementation Facing
Copyright © 2013, AgileFAQs. All Rights Reserved.

4. It Helps to Think of Tests this way...
Business Facing
Acceptance Testing Exploratory Testing
Drives Development
Critique product
Low-fi prototypes UI and Usability Testing
Performance Testing
Unit Testing
System Tests
Technology/Implementation Facing
Copyright © 2013, AgileFAQs. All Rights Reserved.

5. Business Facing
Drives Development
Inside Out
Critique product
Outside In
Technology/Implementation Facing
Brian Marick’s Test Categorization

6. TDD Rhythm
Test, Code, Refactor
Add a Test
Pass
Run the Test
Fail
Make a little
change
Fail
Run the Test
Pass
Refactor

7. Acceptance Test Driven Development
Iteration
Automated
Acceptance Acceptance Tests P
E
Criteria R
F
O
R
Story Automated M
Unit Test E
T
Automated UI N
E
C
Tests S
E
T
S
Automated
Acceptance Tests
Acceptance
Exploratory Criteria
Testing
Copyright © 2013, AgileFAQs. All Rights Reserved.

8. Commercial Break!

9. Copyright © 2013, AgileFAQs. All Rights Reserved.

10. Tech Talks!

13. It all started with...
Veterinarian
Information System
Copyright © 2013, AgileFAQs. All Rights Reserved.

15. Outside In: ATDD
Fitnesse Document:
Assertions: 17 right, 0 wrong, 0 ignored, 0 exceptions
com.vis.billing.fixtures.PaidCashBill
procedure details on the bill
account details
name cost
account number patient name owner name
Routine Office Visit 250
1001 Fluffy Dave Atkins
Rabies Vaccination 50
procedure details
pay Cash
name cost
patient name? owner name? account number? bill no? payment method? amount paid?
Routine Office Visit 250
Fluffy Dave Atkins 1001 1 Cash 300
Rabies Vaccination 50
bill check paid true
account number? owner name? patient name? total? paid?
1001 Dave Atkins Fluffy 300 false
check total 0

16. Outside In: Output

17. ATDD: Another Example
Acceptance test:
class FluffyTest < Test::Unit::TestCase
def test_examination_and_shots
vet = Veterinarian.new
clinic = Clinic.new "Main Line health"
dave = Owner.new "Dave"
fluffy = Patient.new "Fluffy"
dave.has fluffy
visit = clinic.visit(fluffy, vet) do |v|
v.procedure "Rabies vaccination", 50
end
invoice = visit.invoice
assert_equal invoice.to_s,
<<-INVOICE
Routine visit: $200
Rabies vaccination: $50
Total: $250
INVOICE
receipt = clinic.pay_for visit, 100
assert_equal receipt.to_s,
<<-RECEIPT
Paid $100 for Routine visit
Paid $0 for Rabies vaccination
Outstanding: $150
RECEIPT
end
end

18. Outside In: Output

19. Inside Out: Unit TDD
public class ClinicTest {
private Clinic clinic = new Clinic();
public class BillableTest {
@Test
public void amountOnTheReceiptShouldMatchBillableAmount() throws Exception { private static final Account daveSAccount = new Account(101, "Dave");
Billable billable = new Billable() { private static final List<Service> services = new ArrayList<Service>();
public int totalAmount() { return 0; }
}; @Test
Account dave = new Account(101, "Dave"); public void totalBillableAmountShouldBeZeroIfNoServicesAreProvided() {
Billable bill = new Bill(daveSAccount, services);
Receipt rcpt = clinic.payCash(dave, billable); assertEquals("Total amount is not Zero", 0, bill.totalAmount());
}
assertEquals("Amount on receipt does match procedure cost", billable.totalAmount(), rcpt.getAmount());
}
@Test
@Test public void totalBillableAmountShouldBeTotalOfEachServiceProvided() {
public void customerPayesBillableAmountForCashTransaction() throws Exception { services.add(new Procedure("Rabies Vaccination", 250));
final int billableAmount = 56; services.add(new Procedure("Regular office Visit", 50));
class AmountCharged { int charged; };
final AmountCharged charged = new AmountCharged(); Billable bill = new Bill(daveSAccount, services);
Billable billable = new Billable() { assertEquals("Total Amount is not 300", 300, bill.totalAmount());
public int totalAmount() { }
return billableAmount;
} @After
}; public void cleanUp() {
services.clear();
Account dave = new Account(101, "Dave") { }
public void charge(int amount) { }
charged.charged = amount;
}
};
clinic.payCash(dave, billable);
assertEquals("Account is not charged billable amount", billableAmount,charged.charged);
}
}

20. Inside Out: Output

21. Inside Out: Another Example
public class ChargeAccountForServices {
private static final Billable bill = createMock(Billable.class);
private static final Accountable account = createMock(Accountable.class);
private static final Clinic clinic = new Clinic();
@Before
public void setUp() {
reset(account);
reset(bill);
} @Test
public void shouldHaveZeroAmountDueOnReceiptIfCompletePaymentIsMade() {
@Test expect(bill.amount()).andReturn(300);
public void shouldMakePaymentsAgainstAnAccount() { replay(bill);
account.paid(bill); Receipt receipt = clinic.pay(300, bill, account);
replay(account); verify(bill);
clinic.pay(300, bill, account); assertEquals(300, receipt.amount());
verify(account); assertEquals(0, receipt.amountDue());
} }
@Test
public void shouldDisplayAmountDueOnTheReceiptIfIncompletePaymentIsMade() {
expect(bill.amount()).andReturn(500);
replay(bill);
Receipt receipt = clinic.pay(300, bill, account);
verify(bill);
assertEquals(300, receipt.amount());
assertEquals(200, receipt.amountDue());
}
}

22. Inside Out: Example Continued...
public class CreateBillForClientAccount {
private static final List<Service> services = new ArrayList<Service>();
private static final Accountable account = createMock(Accountable.class);
private Bill bill;
@Before
public void setUp() {
reset(account);
}
@Test
public void shouldThrowExceptionIfAccountIsNotDueForPayment() {
expect(account.isPaymentDue()).andReturn(false);
replay(account); @Test
try { public void shouldCreateABillWithTheTotalCostOfAllTheServices() {
new Bill(account, null); IMocksControl control = createControl();
} catch (NoPaymentDueException e) { Service rabiesVaccination = control.createMock(Service.class);
// expected Service routineVisit = control.createMock(Service.class);
} services.add(rabiesVaccination);
verify(account); services.add(routineVisit);
}
expect(account.isPaymentDue()).andReturn(true);
@After expect(account.unpaidServices()).andReturn(services);
public void cleanUp() { bill();
services.clear();
} expect(rabiesVaccination.cost()).andReturn(250);
expect(routineVisit.cost()).andReturn(50);
control.replay();
assertEquals(300, bill.amount());
control.verify();
}
private void bill() throws NoPaymentDueException {
replay(account);
bill = new Bill(account, null);
verify(account);
}
}

23. Inside Out: Output

24. Where do you Stand?
Unit Test x Acceptance test
API x User Interface
State x Interaction
OO x Procedural
Easy x Core
Narrow x Broad
Drive Design x Validate Design
Copyright © 2013, AgileFAQs. All Rights Reserved.

25. Bonus Calculator
Sales Quota Commission % Tax % Result
1200 1100 10 10 9
1200 1500 10 10 0
1200 1200 10 10 0
Copyright © 2013, AgileFAQs. All Rights Reserved.

26. First Few Tests Inside-Out Tests
@Test
! public void noBonusForLowPerformers() {
! ! whenSalesIs(0).andQuotaIs(100).thenIndividualBonusIs(0);
! }
! @Test
! public void noBonusForAveragePerformers() {
! ! whenSalesIs(100).andQuotaIs(100).thenIndividualBonusIs(0);
! }
! @Test
! public void bonusIsBasedOnCommissionPercentage() {
! ! whenSalesIs(110).andQuotaIs(10).andCommissionIs(100).thenIndividualBonusIs(100);
! ! whenSalesIs(110).andQuotaIs(10).andCommissionIs(10).thenIndividualBonusIs(10);
! }
! @Test
! public void bonusIsBasedOnCommissionPercentageAfterTax() {
! ! whenSalesIs(110).andQuotaIs(10).andCommissionIs(100).andTaxIs(10).thenIndividualBonusIs(90);
! ! whenSalesIs(110.02).andQuotaIs(10.01).andCommissionIs(10).andTaxIs(10).thenIndividualBonusIs(9);
! }
Copyright © 2013, AgileFAQs. All Rights Reserved.

27. Sales Tax
Basic sales tax is applicable at a rate of 10% on all goods, except books, food, and
medical products that are exempt. Import duty is an additional sales tax applicable on
all imported goods at a rate of 5%, with no exemptions.
When I purchase items I receive a receipt which lists the name of all the items and
their price (including tax), finishing with the total cost of the items, and the total
amounts of sales taxes paid.
Write an application that prints out the receipt details for these shopping baskets...
Input 1: Input 2: Input 3:
1 book at 12.49 1 imported box of chocolates at 10.00 1 imported bottle of perfume at 27.99
1 music CD at 14.99 1 bottle of perfume at 18.99
1 imported bottle of perfume at 47.50 1 packet of headache pills at 9.75
1 chocolate bar at 0.85
1 box of imported chocolates at 11.25
Output 2:
Output 1:
1 imported box of chocolates: 10.50 Output 3:
1 book : 12.49
1 imported bottle of perfume: 54.65 1 imported bottle of perfume: 32.19
1 music CD: 16.49 1 bottle of perfume: 20.89
Sales Taxes: 7.65
1 chocolate bar: 0.85 1 packet of headache pills: 9.75
Total: 65.15
Sales Taxes: 1.50 1 imported box of chocolates: 11.85
Total: 29.83 Sales Taxes: 6.70
Total: 74.68
Copyright © 2013, AgileFAQs. All Rights Reserved.

28. First Few Outside-In Tests
@Test
public void checkOutEmptyCart() {
assertTotalIs(0);
}
@Test
public void checkOutAnExemptedDomesticItem() {
cart.add(rs100DomesticBook);
assertTotalIs(100);
}
@Test
public void checkOutTaxableDomesticItem() {
cart.add(rs100DomesticMusicCD);
assertTotalIs(110);
}
@Test
public void checkOutExemptedImportedItem() {
cart.add(rs100ImportedBook);
assertTotalIs(105);
}
@Test
public void checkOutImportedItem() {
cart.add(rs100ImportedMacBook);
assertTotalIs(115);
}
Copyright © 2013, AgileFAQs. All Rights Reserved.

29. Medical System
Age Calculating Program
Age Reported in
Greater than 1 Year <Patient Name> is # Years old
> 1 Month & < 1 Year <Patient Name> is # Months old
> 1 Day & < 1 Month <Patient Name> is # Days old
> 1 Hr & < 1 Day <Patient Name> is # Hours old
Doctors and Nurses might like to add and remove new Durations.
For Ex: If they add Decade, and Patient’s age is greater than 10 years,
then age should be reported as <Patient Name> is # Decades old.
Similarly: If they add Week, and Patient’s age is greater than 7 Day, but less than a month,
then age should be reported as <Patient Name> is # Weeks old.
Copyright © 2013, AgileFAQs. All Rights Reserved.

30. First Few Inside-Out Tests
@RunWith(Parameterized.class)
public class DurationTest extends FixedTimeTestCase {
! private final Date date;
! private final String result; @Test
public void canRegisterAndUnregisterLargestDuration() {
! public DurationTest(Object date, Object result) {
assertEquals("31 Years", Duration.since(may3rd1980));
! ! this.date = (Date) date;
! ! this.result = (String) result;
Duration.register("Decades", MILLISECONDS_PER_YEAR * 10);
! }
assertEquals("3 Decades", Duration.since(may3rd1980));
! @Parameters
Duration.unregister("Decades");
! public static List<Object[]> data() {
! ! return new ArrayList<Object[]>() {
assertEquals("31 Years", Duration.since(may3rd1980));
! ! ! { }
! ! ! ! add(new Object[] { may3rd1980, "31 Years" });
! ! ! ! add(new Object[] { jan1st2011, "9 Months" });
! ! ! ! add(new Object[] { oct1st2011, "10 Days" });
! ! ! ! add(new Object[] { oct11nth2011Afternoon, "0 Hours" });
! ! ! }
! ! }; @Test
! }
public void canRegisterAndUnregisterSmallestDuration() {
! @Test
assertEquals("0 Hours", Duration.since(oct11nth2011Morning));
! public void calculatesDurationSince() {
! ! String value = Duration.since(date);
Duration.register("Minutes", MILLISECONDS_PER_MINUTE);
! ! assertEquals("For " + date, result, value);
assertEquals("2 Minutes", Duration.since(oct11nth2011Morning));
! }
Duration.unregister("Minutes");
! @Override
assertEquals("0 Hours", Duration.since(oct11nth2011Morning));
! protected Date currentTime() { }
! ! return oct11nth2011Afternoon;
! }
} Copyright © 2013, AgileFAQs. All Rights Reserved.

31. Meeting Assistant
Copyright © 2013, AgileFAQs. All Rights Reserved.

32. First Few Outside-In Tests
@Test
public void jackWantsThinkingTime() {
jack().isAvailable(now).forEver(); @Test
firstAvailableSlotFor(THIRTY_MINS).is(now); public void jackIsAvailableLaterForARequiredDuration() {
}
jack().isAvailable(now).forNext(TWENTY_MINS);
jack().isAvailable(inTwoHours).forEver();
@Test
firstAvailableSlotFor(THIRTY_MINS).is(inTwoHours);
public void jackBusyForNextTwoHours() { }
jack().isAvailable(inTwoHours).forEver();
firstAvailableSlotFor(THIRTY_MINS).is(inTwoHours); @Test(expected = RuntimeException.class)
} public void jackHasNoTimeToThink() {
jack().isNotAvailable();
@Test
assistant.firstAvailableTimeFor(participants, THIRTY_MINS);
public void jackAndJillAreAvailableRightNowToMeet() { }
jack().isAvailable(now).forEver();
jill().isAvailable(now).forEver();
between(JACK, JILL).firstAvailableSlotFor(THIRTY_MINS).is(now);
}
Copyright © 2013, AgileFAQs. All Rights Reserved.

33. Where do you Stand?
Unit Test x Acceptance test
API x User Interface
State x Interaction
OO x Procedural
Easy x Core
Narrow x Broad
Drive Design x Validate Design
Copyright © 2013, AgileFAQs. All Rights Reserved.

34. Thank you
Naresh Jain
naresh@agilefaqs.com
Copyright © 2013, AgileFAQs. All Rights Reserved.