Improving Elixir Test Suites with Custom Tricks

Jeff Sandberg provides insights into optimizing Elixir test suites by using advanced testing strategies in ExUnit—the built-in test framework in Elixir. He addresses the challenges of redundant setup patterns and offers solutions such as creating __using__ macros, setup functions, and custom assertions. He advocates for the usage of setup functions over universal setup steps to cater to tests with unique configurations and demonstrates leveraging ExUnit's tagging system to fine-tune test setups. Sandberg also introduces the concept of organizing assertions into custom functions or macros, which proves advantageous for cases dealing with HTML element presence checks and event handling in evented Elixir applications. Furthermore, he shares the technique of generating test matrices for testing varied valid and invalid case permutations. Throughout the article, he emphasizes that by understanding that ExUnit tests are 'just Elixir files,' developers can write versatile test code that greatly simplifies and enhances the test-writing process.