First, some background on our client: Power Home Remodeling (“POWER”) is the nation’s largest exterior home remodeler, specializing in exterior retrofits–including windows, siding, roofing, doors, attic insulation, and solar roofing panels. Both inside and out, it’s clear the company has high standards, so we set out to meet them.
Technically speaking, the project is built on Ruby on Rails and follows the component-based architecture design (aka modular monolith), with dozens of components.
A bird’s eye view of our optimization
To achieve this performance boost, we used a combination of RSpec hackery, profiling mastery (for instance, via Stackprof), and, of course, by using our own TestProf toolkit.
First, we conducted a preliminary examination of the whole test suite using Stackprof. That helped us identify some general things to improve: factories, logging, API calls, and so on. Then, after general optimizations, we switched to local test optimizations, for example, analyzing and refactoring specific test files.
Irina Nazarova CEO at Evil Martians
Overall, we submitted (and merged) three PRs, each of them bringing test suite improvements at different levels. In this post, we’ll walk you through these three optimization milestones.
The three pillars of the testing optimization mindset
So that’s the story, but let’s wait a second before we get too deep. Before optimizing tests, it’s important to understand the mindset required to get significant improvements. This mindset relies on the following three pillars.
First, search for the most valuable things to optimize. For instance, optimizing the users factory which is used across all tests will give much more value than optimizing a single monthly_report_spec.rb file (which is rarely changed or used).
