accounts_test.exs

defmodule Blog.AccountsTest do
  use Blog.DataCase

  alias Blog.Accounts

  test "create_user/1 returns {:error, changeset} and rolles back transaction on error" do
    attrs = %{
      contact: %{type: "phone", value: "+1 000 000 0000"},
      name: "",
      password: "password"
    }

    contact_count = Repo.aggregate(Accounts.Contact, :count, :id)

    assert {:error, %Ecto.Changeset{}} = Accounts.create_user(attrs)
    assert ^contact_count = Repo.aggregate(Accounts.Contact, :count, :id)
  end

  test "create_user/1 discards duplicate contacts" do
    contact = %{type: "phone", value: "+1 000 000 0000"}

    assert {:ok, _} = Accounts.create_user(%{contact: contact, name: "name", password: "password"})

    assert {:error, changeset} = Accounts.create_user(%{contact: contact, name: "other", password: "password"})
    assert "has already been taken" in errors_on(changeset).value
  end
end