feat: calculate member.email from user.email

lib/membership/member_email_calculation.ex

@@ -0,0 +1,19 @@
+defmodule Mv.Membership.MemberEmailCalculation do
+  use Ash.Resource.Calculation
+
+  @impl true
+  def load(_query, _opts, _context) do
+    # We need member_email and user.email
+    [:member_email, user: [:email]]
+  end
+
+  @impl true
+  def calculate(records, _opts, _context) do
+    Enum.map(records, fn record ->
+      case record.user do
+        %{email: user_email} when is_binary(user_email) -> user_email
+        _ -> record.member_email
+      end
+    end)
+  end
+end