SpringOne 2021 Session Title: TDD and the Terminator: An Introduction to Test-Driven Development Speaker: Layla Porter, Developer Advocate, .NET communities at VMware

1. @LaylaCodesIt

2. @LaylaCodesIt

3. @LaylaCodesIt
MICROSOFTMVP
GITHUBSTAR
MK.NETORGANISER
C#LOVER
DEVELOPERADVOCATE@VMWARE
LAYLAPORTER

4. @LaylaCodesIt
WHYTDDANDTHETERMINATOR?

5. @LaylaCodesIt
TDDSUCCESSES
•Acceptance Criteria
•Focus
•Interfaces
•Asynchronous development
•Cleaner code
•Safe refactoring
•Fewer bugs
•Increasing returns
•Living documentation

6. @LaylaCodesIt
BACKTOTHETERMINATOR

7. @LaylaCodesIt
THEPROCESS

8. @LaylaCodesIt
GATHERTHEREQUIREMENTS

9. @LaylaCodesIt

10. @LaylaCodesIt
Terminator Requirements
Scan subjects and determine if they
require further investigation
Investigate subjects of interest and
determine if they are the target -
TERMINATE!

11. @LaylaCodesIt
Scan subjects and determine if
they require further investigation

12. @LaylaCodesIt
STARTWITHFAILINGTESTS

13. @LaylaCodesIt
When you write tests after coding you
may be writing them to fit your code
and not your requirements

14. @LaylaCodesIt
RED/GREENREFACTORPATTERN
• Write a failing test
• Write enough code to get the test to pass
• Refactor!

15. @LaylaCodesIt
OVERTOCODE

16. @LaylaCodesIt
REFACTOR!

17. @LaylaCodesIt
public
bool
InvestigateFurther(ISubject
subject)
{
if
(subject.SubjectName.ToLower()
=
=
"woman")
{
return
true;
}
if
(subject.SubjectName.ToLower()
=
=
"girl")
{
return
true;
}
if
(subject.SubjectName.ToLower()
=
=
"man")
{
return
true;
}
if
(subject.SubjectName.ToLower()
=
=
"boy")
{
return
true;
}
return
false;
}

18. @LaylaCodesIt
public
bool
InvestigateFurther(ISubject
subject)
{
switch
(subject.SubjectName.ToLower())
{
case
"woman":
case
"girl":
case
"man":
case
"boy":
return
true;
default:
return
false;
}
}
public

19. public
bool
InvestigateFurther(ISubject
subject)
{
switch
(subject.SubjectName.ToLower())
{
case
"woman":
case
"girl":
case
"man":
case
"boy":
return
true;
default:
return
false;
}
}
[TestCase("woman")]
[TestCase("girl")]
[TestCase("man")]
[TestCase("boy")]
public
void
TerminatorShould_Determine_ToInvestigate
Further
(string
subjectName)
{
var
subject
=
new
Subject
{SubjectName
=
subject
Name};
var
result
=
_sut.InvestigateFurther(subject);
result.Should().BeTrue();
}
[Test]

20. public
bool
InvestigateFurther(ISubject
subject)
{
switch
(subject.SubjectName.ToLower())
{
case
"woman":
case
"girl":
case
"man":
case
"boy":
return
true;
default:
return
false;
}
}
[TestCase("woman")]
public
void
TerminatorShould_DetermineNot_ToInvestigateFurther()
{
var
subject
=
new
Subject
{SubjectName
=
"T1000"};
var
result
=
_sut.InvestigateFurther(subject);
result.Should().BeFalse();
}

21. @LaylaCodesIt
WITHGOODPRACTICES,CODEMANAGEMENTBECOMESINFINITELYEASIER

22. @LaylaCodesIt
TDDFAILURES
•Underestimating the learning curve
•Confusing TDD with unit testing
•Thinking TDD is enough testing
•Not starting with failing tests
•Not refactoring enough
•Not actually doing TDD!

23. @LaylaCodesIt
IMPLEMENTATIONWITHINYOURORGANIZATION
•Can be controversial and is a significant culture change
•Initial drop in productivity can be disconcerting
•Productivity will go up and reworks reduced
•Increased understanding of requirements and their acceptance criteria

24. @LaylaCodesIt
IFYOUTAKEONETHINGAWAYFROMTHISTALK...

25. @LaylaCodesIt
[Test]
public void
TerminatorShould_Determine_ToInvestigateFurther
(ISubject subject)
{
var subject = new Subject{SubjectName = "woman"};
var result = _sut.InfestigateFurther(subject);
result.Should().BeTrue();
}

26. @LaylaCodesIt
[Test]
public void
TerminatorShould_Determine_ToInvestigateFurther
(ISubject subject)
{
var subject = new Subject{SubjectName = "woman"};
var result = _sut.InfestigateFurther(subject);
result.Should().BeTrue();
}
public bool _sut.InvestigateFurther(ISubject subject)
{
return true;
}

27. @LaylaCodesIt
[Test]
public void
TerminatorShould_Determine_ToInvestigateFurther
(ISubject subject)
{
var subject = new Subject{SubjectName = "woman"};
var result = _sut.InfestigateFurther(subject);
result.Should().BeTrue();
}
public bool _sut.InvestigateFurther(ISubject subject)
{
return true;
}
Write the least amount
of code to get your test
to pass.
Return true!

28. @LaylaCodesIt
Twitter:@LaylaCodesIt
GitHub:Layla-P
Email:laylap@vmware.com
Repo:http://bit.ly/tdd-terminator
Deck:http://bit.ly/tdd-deck
Twitch:twitch.tv/LaylaCodesIt
Yaks:https://bit.ly/shaving-a-yak