macro for validating ecto schema fields

validate_schema_fields_and_types.ex

  defmacro validate_schema_fields_and_types(schema, expected_schemas_and_types) do
    quote do
      test "#{unquote(schema)}: it has the correct fields and types" do
        schema = unquote(schema)
        expected_schemas_and_types = unquote(expected_schemas_and_types)

        actual_fields_with_types =
          for field <- schema.__schema__(:fields) do
            type = field_type(schema, field)

            {field, type}
          end

        assert Enum.sort(actual_fields_with_types) ==
                 Enum.sort(expected_schemas_and_types)
      end
    end
  end

  def field_type(module, field) do
    case module.__schema__(:type, field) do
      {:parameterized, Ecto.Embedded, %Ecto.Embedded{related: embedded_type}} ->
        {:embedded_schema, embedded_type}

      {:parameterized, Ecto.Enum, enum_data} ->
        {Ecto.Enum, Keyword.keys(enum_data.mappings)}

      anything_else ->
        anything_else
    end
  end

I typically paste this code into my DataCase