Unit Testing 101

Unit Testing 101 - Presentation Transcript

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