keeping your users happy with testable apps - greg shackles

Greg ShacklesOLO@gshacklesgreg@gregshackles.com

github.com/gshackles

Keeping Your Users Happy

With Testable Apps

Thursday, May 9, 13

TDD

Thursday, May 9, 13

TDDKISSSOLID

BDDDRY

SOC

YAGNI

DDD

SRP OCPLSP ISP

DIPXP

IOC CQS

Thursday, May 9, 13

Thursday, May 9, 13

Why Test?

Thursday, May 9, 13

Stability

Thursday, May 9, 13

Stability

•Obvious, but important

Thursday, May 9, 13

Stability

•Obvious, but important

•Refactor and iterate with a safety net

Thursday, May 9, 13

Stability

•Obvious, but important

•Refactor and iterate with a safety net

•Compilation is only the first unit test

Thursday, May 9, 13

Stability

•Obvious, but important

•Refactor and iterate with a safety net

•Compilation is only the first unit test

•Verify cross-platform compatibility

Thursday, May 9, 13

“I don’t have time to write tests!”

Thursday, May 9, 13

“I don’t have time to NOT write tests!”

Thursday, May 9, 13

Once It’s Out, It’s Out

Thursday, May 9, 13

Once It’s Out, It’s Out

•This isn’t the web

Thursday, May 9, 13

Once It’s Out, It’s Out

•This isn’t the web

•Difficult and expensive to

fix

Thursday, May 9, 13

Once It’s Out, It’s Out

•This isn’t the web

•Difficult and expensive to

fix

•Quality bar has been

Thursday, May 9, 13

The Happy Path

Thursday, May 9, 13

•Improves design

The Happy Path

Thursday, May 9, 13

•Improves design

•More shared code (not just mobile apps)

The Happy Path

Thursday, May 9, 13

•Improves design

•More shared code (not just mobile apps)

•Optimize independently of a platform

The Happy Path

Thursday, May 9, 13

•Improves design

•More shared code (not just mobile apps)

•Optimize independently of a platform

•IterationSpeed++

The Happy Path

Thursday, May 9, 13

•Improves design

•More shared code (not just mobile apps)

•Optimize independently of a platform

•IterationSpeed++

•FACT: Green tests are good for the soul

The Happy Path

Thursday, May 9, 13

What To Test?

Thursday, May 9, 13

What to Test?

Thursday, May 9, 13

What to Test?

•100% code coverage != the goal

Thursday, May 9, 13

What to Test?

•100% code coverage != the goal

•Test parts that provide value

Thursday, May 9, 13

What to Test?

•100% code coverage != the goal

•Test parts that provide value

•Testing platform code can be difficult

Thursday, May 9, 13

What to Test?

•100% code coverage != the goal

•Test parts that provide value

•Testing platform code can be difficult

•Start small

Thursday, May 9, 13

Thursday, May 9, 13

!!Unit  Tests

Thursday, May 9, 13

!!

!!

Unit  Tests

Integra-on  Tests

Thursday, May 9, 13

!!

!!

!!

Unit  Tests

Integra-on  Tests

UI  /  UX  Tests

Thursday, May 9, 13

!!

!!

!!

Unit  Tests

Integra-on  Tests

UI  /  UX  Tests Mixed

Automated

Thursday, May 9, 13

Unit / Integration Tests

Thursday, May 9, 13

Unit / Integration Tests

•Automated

Thursday, May 9, 13

Unit / Integration Tests

•Automated

•Low friction

Thursday, May 9, 13

Unit / Integration Tests

•Automated

•Low friction

•Leverage tooling

Thursday, May 9, 13

Unit / Integration Tests

•Automated

•Low friction

•Leverage tooling

•NUnit (Lite)

Thursday, May 9, 13

Unit / Integration Tests

•Automated

•Low friction

•Leverage tooling

•NUnit (Lite)

•Run on all

platforms

Thursday, May 9, 13

Unit / Integration Tests

•Automated

•Low friction

•Leverage tooling

•NUnit (Lite)

•Run on all

platforms

•Simulator vs

Device

Thursday, May 9, 13

Mocking

Thursday, May 9, 13

Mocking

•Limited options

Thursday, May 9, 13

Mocking

•Limited options

•Manual mocking

Thursday, May 9, 13

Mocking

•Limited options

•Manual mocking

•Code generation, T4

github.com/gshackles/

Muntz

Thursday, May 9, 13

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Mocking

interface IService{! string Foo(string bar);}!class MockService : IService{! public Func<string> FooBody { get; set; }! !! public Foo(string bar)! {! ! return FooBody();! }}

Thursday, May 9, 13

Manual Testing

Thursday, May 9, 13

Manual Testing

•User feedback is

critical

Thursday, May 9, 13

Manual Testing

•User feedback is

critical

•UX testing

Thursday, May 9, 13

Manual Testing

•User feedback is

critical

•UX testing

•Exploratory testing

Thursday, May 9, 13

MVVM

Thursday, May 9, 13

MVVM

•MvvmCross

Thursday, May 9, 13

MVVM

•MvvmCross

•Shared, testable view models

Thursday, May 9, 13

MVVM

•MvvmCross

•Shared, testable view models

• Improved IoC support

Thursday, May 9, 13

MVVM

•MvvmCross

•Shared, testable view models

• Improved IoC support

•Databinding keeps views thin

Thursday, May 9, 13

DEMOThursday, May 9, 13

Q&AThursday, May 9, 13