TDD Is Fun

Today DHH published a blog post about TDD being dead (to him at least). It’s really not that surprising since from what I know (please correct me if I’m wrong) David’s experience is mostly based on building web apps with Rails. I get that, I really...

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Common Pitfalls Of Code Metrics

Code metrics and code metric tools can be both helpful and harmful. The difference between the two is learning to interpret the results and use the feedback to improve yourself and your code.

I have a lot of experience with code metric tools. Over...

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TDD and ActiveRecord in Rails

I don’t have exact numbers but I believe TDD isn’t really popular amongst rails developers. This shouldn’t be a surprise given that the two of the most complex elements in the rails stack, models and controllers, are very convoluted concepts and are...

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Virtus 1.0.0 Released

I’m happy to announce that after 1486 commits Virtus 1.0.0 has been released. It comes with a lot of neat changes, improvements and new features.

Here’s a quick summary of my favorite additions and changes.

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Mutation testing with Mutant

When working on DataMapper and its libraries we put a lot of effort into testing. Our libraries must have 100% code coverage and even that is not enough. What we want to achieve eventually is full mutation coverage. What is that? If you’ve ever heard...

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DataMapper 2 Status and Roadmap

UPDATE: This article is outdated. DataMapper 2 was renamed to Ruby Object Mapper (ROM). For more info check out

We’ve been really busy working on the mapper part of DataMapper 2 for the last few months. This gives us more clarity about...

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Subclassing Module For Fun and Profit

You think you’ve done everything with Ruby? How about subclassing Module? It’s an interesting technique that I’ve been experimenting with lately. One of the downsides of using modules in Ruby is that a module doesn’t have a state. When you mix it into...

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