1 files changed, 65 insertions, 0 deletions
diff --git a/test/support/model_case.ex b/test/support/model_case.ex
new file mode 100644
index 0000000..9f16428
--- /dev/null
+++ b/test/support/model_case.ex
@@ -0,0 +1,65 @@
+defmodule TheTranscriberBackend.ModelCase do
+  @moduledoc """
+  This module defines the test case to be used by
+  model tests.
+
+  You may define functions here to be used as helpers in
+  your model tests. See `errors_on/2`'s definition as reference.
+
+  Finally, if the test case interacts with the database,
+  it cannot be async. For this reason, every test runs
+  inside a transaction which is reset at the beginning
+  of the test unless the test case is marked as async.
+  """
+
+  use ExUnit.CaseTemplate
+
+  using do
+    quote do
+      alias TheTranscriberBackend.Repo
+
+      import Ecto
+      import Ecto.Changeset
+      import Ecto.Query
+      import TheTranscriberBackend.ModelCase
+    end
+  end
+
+  setup tags do
+    :ok = Ecto.Adapters.SQL.Sandbox.checkout(TheTranscriberBackend.Repo)
+
+    unless tags[:async] do
+      Ecto.Adapters.SQL.Sandbox.mode(TheTranscriberBackend.Repo, {:shared, self()})
+    end
+
+    :ok
+  end
+
+  @doc """
+  Helper for returning list of errors in a struct when given certain data.
+
+  ## Examples
+
+  Given a User schema that lists `:name` as a required field and validates
+  `:password` to be safe, it would return:
+
+      iex> errors_on(%User{}, %{password: "password"})
+      [password: "is unsafe", name: "is blank"]
+
+  You could then write your assertion like:
+
+      assert {:password, "is unsafe"} in errors_on(%User{}, %{password: "password"})
+
+  You can also create the changeset manually and retrieve the errors
+  field directly:
+
+      iex> changeset = User.changeset(%User{}, password: "password")
+      iex> {:password, "is unsafe"} in changeset.errors
+      true
+  """
+  def errors_on(struct, data) do
+    struct.__struct__.changeset(struct, data)
+    |> Ecto.Changeset.traverse_errors(&TheTranscriberBackend.ErrorHelpers.translate_error/1)
+    |> Enum.flat_map(fn {key, errors} -> for msg <- errors, do: {key, msg} end)
+  end
+end