Elixir Testing

ExUnit is built into Elixir and fits naturally with immutable data and explicit behavior checks.

ExUnit

Use ExUnit for assertions, setup blocks, and expressive test organization.

Test boundaries

Test public behavior, not private implementation details, unless a low-level rule must be protected.

Behavior checks

Focus on stable outputs, error paths, and the contract between modules.

Practice

  1. Write one ExUnit test skeleton.
  2. Identify one behavior instead of an implementation detail.
  3. Write one note about why immutable data improves test clarity.