You need
some tests yo!
Dave Bouwman // CTO // DTSAgile

the “big” ideas

prove
code
works

prove
design
works

catch
regression

unit testing
101

Instantiate class under test…
Call Method…
Check Results…
Call Method…
Check Results…

good tests are…
independent
repeatable
self-contained*
professional

good tests are…
focused

tools!

“unit testing
on crack”
Scott Hanselman
www.hanselman.com

writing
tests

simple methods
with simple signatures
mean simple tests

complex methods
with complex signatures
mean…
complex tests

most
ArcObjects
applications
fall in this
category

for testing
design we must

separation
of concerns

a class has
single
purpose

stay
inside
its
box

user interface
(events + logic + data access)

private void ButtonOn_Click(){
//read values from controls
//apply business logic
//connect to database
//update data
//update interface
}

user interface
objects
business
objects
data access
objects

Private void ButtonOn_Click(){
//read values from controls
//apply business logic
//send changes to DAL
//connect to database
//update data
//update interface
}

n-tier
architecture

user interface WPF/Silverlight
objects
business
objects
unit
tests
data access
objects

design
patterns yo

model
view
controller

ASP.NET MVC
released!!
http://asp.net/mvc

dependency
management

dependencies

1
created
by the
constructor

private IAccountRepository _accountRepository;
private IFormsAuthentication _formsAuthentication;
private ILogService _logger;
public AccountController()
{
_accountRepository =
new AccountRepository(_connectionString);
_logger = new Logger();
_formsAuthentication = new FormsAuthentication();
}

what about
testing

good tests are…
independent
repeatable
self-contained*
professional

“tight coupling”
external
dependencies
in the
tests

internal
dependencies

and
separate
them

2 pass
dependencies
into the
constructor

dependency
injection

private IAccountRepository _accountRepository;
private IFormsAuthentication _formsAuthentication;
private ILogService _logger;
public AccountController(IAccountRepository accountRepository,
IFormsAuthentication formsAuthentication,
ILogService logger)
{
_accountRepository = accountRepository;
_formsAuthentication = formsAuthentication;
_logger = logger;
}

pushed
the
problem
up a
level

inversion
of control

I need an
AccountController!
configuration
Global.asax.cs

Castle Windsor
Spring.NET
mvccontrib IoC
StructureMap
Unity
http://mvccontrib.codeplex.com

back to
unit testing…

isolated
testing

&
mock
fakes
stubs

code you
wrote generated
on-the-fly

fake
objects

stub/mock
objects

tools!

rhinomocks
http://ayende.com/projects/rhino-mocks.aspx

ArcMap
development

not
our
box

separate
logic
from
wiring

emulate
events
fromArcMap

my code
sinks…

in
ArcMap
Business
IEditEvents Shim
Logic
ArcMap

under
test
Business
Test
Logic

test
your
code
not
ESRI’s

ArcEngine
Applications

it’s
our
box

design
matters.

ArcGIS
Server

testing
Web ADF…

custom
services

COM
Utilities
SOC
COM
Utility
WebService
ArcGIS Server

Server
Object
Extensions SOC
SOE
WebService
ArcGIS Server

testable
classes
IServerObjectExtension
COM COM
SOE
Utility Utility
(ArcObjects) (ArcObjects)

but i’m too
cool for COM…

jsunit
D.O.H. Unit Testing
FlexUnit
Silverlight Harness

http://mbunit.com
http://testdriven.net
resources http://ASP.NET/mvc
http://mvccontrib.codeplex.com
http://castleproject.org
http://ayende.com/projects/rhino-mocks.aspx

i’m in teh codez
writin teztz!

and nao u
can too!

http://blog.davebouwman.net
dbouwman@dtsagile.com
questions
http://twitter.com/dbouwman
http://slideshare.com/dbouwman