LobstersFriday · May 15, 2026FREE

How do I write Elixir tests?

elixirtestingexunit

The article, published on Lobsters by hauleth, offers practical advice for writing tests in Elixir using the built-in ExUnit framework. Key points include organizing tests into describe blocks for readability, using test names that describe expected behavior, and preferring pattern matching in assertions for clarity. The author advises against testing private functions directly and suggests using mocks sparingly, favoring dependency injection. For asynchronous code, the article recommends using `async: true` with caution and ensuring test isolation. Concrete examples demonstrate how to test GenServers, Ecto queries, and Phoenix controllers. The author also touches on property-based testing with StreamData and the importance of running tests in CI. The tone is instructional, aimed at intermediate Elixir developers looking to improve their testing practices.

// why it matters

Improves test quality and maintainability in Elixir projects.

Sources

Primary · Lobsters
▸ Read original at hauleth.dev