Curiosum TILs

How to run tests in Elixir IEx shell

Hey! Have you ever wondered about tests running inside the IEx shell? For a long time, I was convinced that it’s not really possible. And as it turns out - that’s not really straightforward. You won’t easily find information about that in the documentation.

How to safely handle related database operations with Ecto Multi

Sometimes you need to do some database operations at once. A simple example: User-A transfers money to User-B. Updating just one balance at the time creates a risk of data desynchronization. What if the first DB operation goes well but updating the second user’s data fails? Sounds like a hard to catch vulnerability.