I am looking into Test Driven Development (TDD) these days for the reasons I mention in this post, and I came across a seemingly famous book called, Test-Driven iOS Development. I have to say this… Stay away.

Maybe I am enjoying this critic business, but I also like to share my findings and try to raise the expectations for content that users consume. Basically, I found a few flaws in the book that I would like to point out:

Being a Critic

The thing that really bewildered me is Chapter 3, which presents an example on how to write a simple unit tests in iOS. I mean, this is the most basic example, it should be 100% perfect in every way, since:

  1. People reading it will probably fresh to the idea, and accept anything thrown at them.
  2. It easily sets a minimum basic standard and norm on how to write tests.

So, what is the problem?

The book tries to describe how you one should choose test cases for a temperature unit conversion app:

[…] I can see that I might want to test conversions at absolute zero (– 273.15 ° C/– 459.67 ° F) and the boiling point of water (100 ° C/ 212 ° F) to ensure that the conversion method works across a wide choice of input values. – Test-Driven iOS Development.

I totally agree with “to ensure that the conversion method works across a wide choice of input values”. What I totally refuse is the choice of tests!! It doesn’t freakin matter what the boiling point of water is! I hope I don’t have to look up from wikipedia those numbers to write tests one day…

It should be completely systematic, objective, and … systematic! So, what you would want to test here is, a positive integer, a negative floating point number, … etc. Those are the values that would make much more sense to actually test.


I have been reading books, not as much as I should, but I read a few… Most of them were an utter and complete waste of time. I realize that some authors write a book for the sake of writing a book. That is sad.

On the other hand, when you look at a book like Effective Programming: More Than Just Writing Code, which is a compilation of blog posts written deep from within the heart and soul of the author, you actually find invaluable riches.

I know, it seems like this book is the only thing I ever talk about, but I recently realized why I thought I hated reading books. I am hopeful to find more great books that deliver content in such unique manner.