A practical example of TDD Outside-in (BDD) with Elixir

This is a practical example of practicing Outside-In TDD (BDD) using Elixir. Joe uses Test Driven Development and shows you the ropes.
The Code Kata is called Greeting Service and it can be found at github.com/joebew42/greeting-...
Other solutions of the same code kata can be found here: github.com/joebew42/elixir_ou... (look at the three different branches)
More information about the practice of TDD Outside-In:
- Book: Growing Object Oriented Software Guided By Tests (www.growing-object-oriented-so...)
- Wiki: London school TDD - The Outside-in approach (github.com/testdouble/contrib...)
- Video: Bank Account Kata by Sandro Mancuso ( • Outside In TDD part I )
More on Clean Code, TDD, Refactoring and Working with Legacy Code can be found here: github.com/joebew42/study-path
Joe Bew on Twitter: / joebew42

[@steffenuhlig1970]

Thanks for publishing this in such detailed steps. The console colors red on blue are barely readable for me. Could you perhaps use a different color scheme next time? Keep up the good work!

[@angelleen4369]

Wow. I actually didnt know about this one. Thanks for sharing!

[@hyperrealhank]

I've learned so much about software development from this video. I hope you'll continue making these!

[@JoeBew]

Hi Henry, I am really glad you have found this video of such value. If you look in my channel you will find a few videos about refactoring techniques. Hopefully, more videos will come. In the description of the videos you can find more information.

[@hyperrealhank]

@@JoeBew I really liked this one in particular because it's written in elixir. When watching tdd in other languages I feel less attached to the content because there are so many emotions and intuitions that change when writing in a different kind of language

[@sagyro]

Great video. I'm glad I found it since I'm just getting started in Elixir! Also It's cool that you found my java version of this kata inspiring, thanks for the credits :)

[@JoeBew]

Hi Sagy, glad to hear you liked the video, thanks! I don't remember if I discussed the Dependency Injection, but in Elixir you can inject using the Application.get_env (that seems to be a common way), you can try to repeat the same Code Kata using different styles of dependency injection. Another note: I did not use any mocks for this example, but in Elixir there is a mocking library available, called Mox, and it would be nice to try the code kata using mocks, instead.

[@joseoliveira8423]

Awesome content! Which framework is this?

[@JoeBew]

Hi José, for this screen cast I have used Elixir, with no frameworks.

[@joseoliveira8423]

@@JoeBew Oh, sorry, I was just beginning... But then I noticed. Thank you so much!

[@LordOkamiGameDev]

The animation showed when test passed is postproduction made, isn't it?

[@JoeBew]

Hi, yes they are postproduction animation.

[@lordokamifpv6243]

@@JoeBew Thx, I was thinking it will be awesome to have it in real time 🎇