Hi all,

How do you write your context tests (create_thingy(attrs)) when there are a lot of associations that need to be created first?

Here is a contrived example. Let’s says I have a Door model that I’d like to test the color, material, price, etc..

A Door cannot be created without having to first create a Wall
A Wall cannot be created without having to first create a House
A House cannot be created without having to first create a Blueprint
A Blueprint cannot be created without having to first create a Contract
A Contract cannot be created without having to first create a Client
A Client cannot be created without having to first create a Prospect
and on and on…

I have a method in my Building context that sort of looks like this:

  def create_door(attrs \\ %{}) do
    %Door{}
    |> Door.changeset(attrs)
    |> Repo.insert()
  end

Ideally in my test I’d like to write something like:

{:ok, door} = create_door(%{price: 1_234, material: "wood", color: "white"})
assert door.color == "white"

However I cannot create the Door without passing in a wall_id and since that field cannot be null I’d need to create a Wall. The creation process then has to go all the way up to … create_user. Surely I’ve missed something huge I can do that will still make me confident in the production code, but won’t make testing difficult.

Any tips or suggestions are greatly appreciated.