Design Tech Talk Series Presents: OO Design for Testability

Google Tech Talk
October 6, 2009

ABSTRACT

Presented by Miško Hevery.

We design our code for performance, maintenance, simplicity, extensibility and other goals, but most of us do not think about testability as a design goal, yet verifying the correctness of our code is of great importance. What does it mean to have testable code, and what kind of trade offs does one have to think about when designing for testability. Turns out that testable code is well designed code, and it has many of the characteristics we search for such as low cohesion, separation of concerns, proper encapsulation and many others.

Category:

Science & Technology

Tags:

• google
• tech
• talk
• software
• testing

[neohubris]

Misko thank you very much for doing these talks. Your clean code talks has helped my work tremendously.

[espinchi]

Great talk!

[vaulttech]

I've searched for the other 3 talks (since this is the fourh) but I couldn't find them. Can someone please give me the link?

[SKOMonster]

I meant LoginPage, sorry.

[SKOMonster]

@edovale

Well I think he refered to the latter case as "the class with singleton lifetime" and not a singleton (I noticed this ambiguity only when he talked about the Login_class). And he did not say it was problematic to test because it had singleton lifetime, he said it was problematic owing to it's dependencies, and therefore that particular class might have been better as short-lived class with different dependencies, that wouldn't force it to break the law of Demeter.Am I getting it right?

[edovale]

Very nice talk. A bit ambiguous with the term singleton. There is the singleton pattern as described in the Gof4 book which is the one that is problematic to test and there is the single instance of a class throughout the life of the application. There is nothing wrong with the latter IMO.

[spamero2]

Misko Hevery for president!

[saip106]

Thanks for the great presentation. 

[pereznels]

Awesome presentation!