99 problems of slow tests

A presentation at Paris.rb in in Paris, France by Vladimir Dementyev

Writing tests is a significant part of the Ruby development process.

The test suite’s run time increases as the application evolves. We don’t care until we found ourselves wasting too much time waiting for the green light.

What makes tests slow and how to heal them? Let’s answer these questions.

I would like to start the talk by answering several questions, e.g., “Do you write tests?”, “How long does your test suite run?”, etc. Some stats & charts.

In the first part of the I would like to share a few real-life stories: “Our tests were slow, we did some investigation, and the reason was X.” Most of these reasons are related to incorrect environment configuration for tests.

The second part of the talk is answering the question: how to find bottlenecks in your tests?

I’m going to introduce the tool called TestProf–a toolbox for profiling test suites and a set of ready-made recipes to write faster tests and fix your existing slow codebase.

Let’s make tests faster!

Video

Resources

The following resources were mentioned during the presentation or are useful additional information.

Buzz and feedback

Here’s what was said about this presentation on Twitter.