Caleb Jenkins
developingUX.com
ProactionMentors.com @calebjenkins

I’ll be
leaving
my
clothes
on
CODING Naked!

Development Engineering Process
Object Orientation Automated Tests Agile, Lean, XP
SOLID Source Control Team Dynamics
Patterns Automated Builds Continuous Learning
Secure Coding

Is TDD
only for
coding
elites?

or something for
every developer?

How do we make Automated
Tests the norm?

make coding without
tests as
uncomfortable as coding
naked

and as fun as playing
with Legos

* this is not me

Development
…and you build the Legos!

Building Better
Legos

Do you write after the fact Tests
or design with executable
specifications?
A test confirms what was done
blue prints or specifications
define what needs to be done.
Automated Unit Tests do both!

What was
What
should be
Discuss: done
done
Building Inspector
vs
Architect Designer
Which are you?
Which do you need?
What’s the difference?
Unit Tests
do both

what are the 4 big parts of unit tests?
16

Code Tests
Test Framework Test Runner
17

your application
Code
what you want to test
Tests
Test Framework Test Runner
18

your test code
the code that tests the
Code Tests
code that you wrote or are
going to write
Test Framework Test Runner
19

Code Tests
attributes and asserts
the framework provides
the attributes and asserts
Test Framework
so we know what the tests Test Runner
are doing.
Examples: nUnit jUnit
cppUnit
20

Code Tests
runs the tests
often associated with the
test framework; is
Test Framework Test Runner
distinctly separate.
sometime integrated in
IDE, CI Server or stand
alone exe
21

Code Tests
Test Framework Test Runner
22

Test Runner
Tests
Test Framework
Tests
Code
Tests
Tests
Tests
24

1 Have a runner

Pick a Test
1 Framework

Test Framework
27

Pick a Test
2 Runner

Test Runners
nUnit Test Runner
29

Test Runners
nUnit Test Runner
Visual Studio (VS Test)
30

Test Runners
nUnit Test Runner
Visual Studio (VS Test)
CodeRush / ReSharper
31

Test Runners
nUnit Test Runner
Visual Studio (VS Test)
CodeRush / ReSharper
32 Continuous Integration (Team City)

Write Test
3 Code

Test Code … 3 A’s
Arrange Act Assert
Arrange– Set up the scenario and the initial input values.
Often in a common [TestFixtureSetup] or [Setup] method
Act - Action that creates the outcome that is being tests, usually
calling some method in your code to test the result.
Assert – Is a boolean statement to your testing framework to
declare the expected outcome. Results in Pass or Fail
34

Building better Lego’s
UI
UI Logic Tests are small
App Domain Domain Validation
Tests are fast
Integration Service Proxy Tests focus on one thing
Data Logic
Data Access

Simple Tests (return values) with no dependencies…
Test Runner
Test Code
UI Logic
App Domain Domain Validation
Unit Tests focus on a Unit
Test a unit in isolation from other units
Control input => Testable output

Demo
Let’s write
some tests!

2 Set the Scene
context makes all the difference!

Discussion
Defining Behavior
as a <role>,
I will <function>
so that <value>

Discussion
what if our “tests”
given <class> to test
when <setup> scenario
should <test> outcome
matched our
language?

Discussion
BDD

Resources & Frameworks
BDD
more than TDD done right
http://neelnarayan.blogspot.com/2010/07/bdd-is-more-than-tdd-done-right.html
behavior driven, test driven, domain driven
http://lucisferre.net/2011/02/05/behavior-driven-test-driven-domain-driven-design/
nBehave, nSpec, SpecFlow,
StoryQ, mSpec, StorEvil
introducing BDD
http://dannorth.net/introducing-bdd/

3 Handle your
dependencies

Dependencies
“The single greatest thing that you can do
to make your code more testable and
healthy is to start taking a Dependency
Injection approach to writing software”
Real World .NET, C# and Silverlight
Caleb Jenkins (Wrox Press 2012)

How do you test this
UI
UI Logic
App Domain Domain Validation
Integration Service Proxy
Data Logic with these
Data Access dependencies

UI
UI Logic
App Domain Domain Validation
Integration Service Proxy
Data Logic
Data Access

Test Runner
Test Code
UI Logic
App Domain Domain Validation
Integration Service Proxy
Dependency Injection + Interfaces
Faked dependencies to increase unit isolation
Leverage mocking frameworks makes life better

Note:
Dependency Injection
will turn you in to a complete
coding Ninja, however the
full scope of DI with any of
the many DI frameworks is
beyond the scope of this talk

http://developingUX.com/DI/

Mocking Framework
“A mocking framework allows you to create fake classes on
the fly in-line with your test code. That is a bit of a
simplification, mocking frameworks use a combination of
emits, reflection and generics to create run-time instance
implementations of .NET Interfaces – whew, that’s a mouthful
- it’s a whole lot easier to say that they create fake classes on
the fly!”
Real World .NET, C# and Silverlight
Caleb Jenkins (Wrox Press 2012)

Mocking in .NET

Bringing DI together

IData mockData = MockRepository.GenerateMock<IData>();
mockData.Expect(x => x.getAll<account>())
.Return(sampleAccounts).Repeat.Once();
IAccountServices accountService
= new AcmeAccountService(mockData);
var act = accountService.GetAccount(known_account_id);
mockData.VerifyAllExpectations();

IData mockData = MockRepository.GenerateMock<IData>();
mockData.Expect(x => x.getAll<account>())
.Return(sampleAccounts).Repeat.Once();
IAccountServices accountService
= new AcmeAccountService(mockData);
var act = accountService.GetAccount(known_account_id);
mockData.VerifyAllExpectations();

IData mockData = MockRepository.GenerateMock<IData>();
mockData.Expect(x => x.getAll<account>())
.Return(sampleAccounts).Repeat.Once();
IAccountServices accountService
= new AcmeAccountService(mockData);
var act = accountService.GetAccount(known_account_id);
mockData.VerifyAllExpectations();

Demo
Mocking
Confidential

the problem with edges

UI Business Data

Edges are
Hard to Test
UI Business Data

Testing edges
can be like
testing to see if
you’re good at
cliff jumping
Confidential

That’s not me
Confidential

You’re either an
expert and it works…
..or you’re
stuff on a rock.
Confidential

Edges are
Hard to Test
UI UI Data
Business Data
Logic
Logic

Edges are still
Edges are
Hard to Test
Data
UI Data
UI
Business
Logic Logic
by separating UI/Data edges from
UI/Data logic we’re increasing the testable area

Edges are still
Edges are
Hard to Test
Data
UI Data
UI
Business
Logic Logic
we’ve also made it easier to implement
by separating UI/Data edges from
various UI and Data platforms
UI/Data logic we’re increasing the testable area
without affecting the application logic

MVC
MVP
M-V-VM
72

MVC
MVP
M-V-VM
73

Model View Controller (MVC)
• All input is routed to a controller
• Example Web Scenarios
• ASP.NET MVC Framework
Model View Presenter (MVP)
• View initiates Presenter
• UI Logic is contained in Presenter
• Example WinApp & ASP.NET Webform apps
Model View ViewModel (MVVM)
• ViewModel is a view specific model
• VM is can mash up application models
• UI logic contained in ViewModel
• Example Rich Data binding Scenarios
(WPF / Silverlight)
74

Application
UI Layer
Business Layer
Data Layer (IRepository)
Data Logic
IRepository
Repository handles the CRUD and “bare metal” Data Interactions.
Consider ADO.NET, nHibernate, EF, LinqToSQL
Data Base 76

1 Have a runner

1 Have a runner
2 Set the Scene

1 Have a runner
2 Set the Scene
3 Handle your
Dependencies

Development Team Work Process
Object Orientation Automated Tests Agile, Lean, XP
SOLID Source Control Team Dynamics
Patterns Automated Builds Continuous Learning
Secure Coding

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@calebjenkins http://developingux.com
@proactionmentor caleb@calebjenkins.com