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Next requirement is to check for exceptional cases an throw. I use JUnits ExpectedException Rule to test exceptions and their message. I use more Java8 Streams features to check for the exceptional cases and to build the exception message. As always, I clean up after myself. ► All Kata Episodes: […]

String Calculator Kata 03 – Testing Exceptions (JUnit) & Streams ...

March 7, 2015 in Code Kata / Let's Develop / String Calculator tagged Java 8 / Java Streams / JUnit / TDD by letsdeveloper

Next task in the kata is to allow arbitrary delimiters in our sequence of numbers. Delimiters are specified by an (optional) prefix in the string. Hence, we need some logic to split and interpret both parts. First, I get it to work, then, I refactor to clean up. ► All […]

String Calculator Kata 02 – Specify Delimiters

March 7, 2015 in Code Kata / Let's Develop / String Calculator tagged Java 8 / Java Streams / TDD by letsdeveloper

This kata is about parsing a sequence of numbers from a string and adding them up. I focus on Java 8 streams in the implementation, to explore this particular language feature. In this first episode, I get the basic functionality to run. Test-driven, of course. ► All Kata Episodes: http://goo.gl/xicl9c […]

String Calculator Kata 01 – IntStream

March 7, 2015 in Code Kata / Let's Develop / String Calculator tagged Java 8 / Java Streams / TDD by letsdeveloper

Third step: We want the loop to render the game. This has to happen after the update, otherwise the game might lag. Order is easy to ensure with handcrafted stubs! ► All Game of Life Episodes: http://goo.gl/xc59GX ► Let’s Develop! http://letsdeveloper.com ► Don’t Miss an Episode: http://goo.gl/whzDi1 ► Test-Driving the […]

Conway’s Game of Life #12 – Game Loop – Render

March 2, 2015 in Conway's Game of Life / Let's Develop tagged Game Development / TDD by letsdeveloper

Prime Factors is a simple, yet interesting kata about implementing prime-factor computation. The kata was developed by Uncle Bob, together with his son. I perform it here in Vanilla Java. ► All Kata Episodes: http://goo.gl/uTSO9B ► Let’s Develop! http://letsdeveloper.com ► Don’t Miss an Episode: http://goo.gl/whzDi1 ► Kata: http://butunclebob.com/ArticleS.UncleBob.ThePrimeFactorsKata ► The […]

Code Kata – Prime Factors

March 2, 2015 in Code Kata / Let's Develop tagged TDD by letsdeveloper

Ok, now lets make it a loop. Most time I spend on the test, adapting the test stub and the existing tests to the changes. The test design is evolving and leads the way. ► All Game of Life Episodes: http://goo.gl/xc59GX ► Let’s Develop! http://letsdeveloper.com ► Don’t Miss an Episode: […]

Conway’s Game of Life #11 – Game Loop – Loop

February 24, 2015 in Conway's Game of Life / Let's Develop tagged Game Development / TDD by letsdeveloper

First thing we need is for the loop to update our game state on each iteration. While we write our test, we adjust the design to the new requirements and adapt our test-stub game to support the test we want to write. But hey, it’s not a loop yet! ► […]

Conway’s Game of Life #10 – Game Loop – Update

February 18, 2015 in Conway's Game of Life / Let's Develop tagged Game Development / TDD by letsdeveloper

Using Google’s Guava I can considerably simplify my implementation. I trust Google developers. Those guys generally know their handiwork. After this refactoring, I’m finally content with my implementation. ► All Potter Kata Episodes: http://goo.gl/m9E4vF ► Let’s Develop! http://letsdeveloper.com ► Don’t Miss an Episode: http://goo.gl/whzDi1 ► CodingDojo: http://codingdojo.org/cgi-bin/index.pl?KataPotter ► The Code: […]

Code Kata – Potter #7 – Introducing Google’s Guava

February 14, 2015 in Code Kata / Let's Develop / Potter tagged Guava / TDD by letsdeveloper

Finally, let’s add the discount rule for 5 books. To finish it up, I write some more tests, including an integration example, to see if everything works. All functionality is in the code, but I smell potential for improvements! ► All Potter Kata Episodes: http://goo.gl/m9E4vF ► Let’s Develop! http://letsdeveloper.com ► […]

Code Kata – Potter #6 – Discount for 5 Books ...

February 14, 2015 in Code Kata / Let's Develop / Potter tagged TDD by letsdeveloper