refactor(member): share Ash error formatting across member-show components

test/mv_web/helpers/ash_error_helpers_test.exs

@@ -0,0 +1,63 @@
+defmodule MvWeb.Helpers.AshErrorHelpersTest do
+  @moduledoc """
+  Tests for format_error/1, the shared Ash error formatter used by the
+  member show LiveComponents.
+  """
+  use Mv.DataCase, async: true
+
+  import MvWeb.Helpers.AshErrorHelpers
+
+  describe "format_error/1" do
+    test "joins messages of an Ash.Error.Invalid with commas" do
+      error = %Ash.Error.Invalid{
+        errors: [%{message: "exit_date must be after join_date"}, %{message: "another"}]
+      }
+
+      assert format_error(error) == "exit_date must be after join_date, another"
+    end
+
+    test "falls back to inspect for invalid sub-errors without a message" do
+      error = %Ash.Error.Invalid{errors: [:boom]}
+
+      assert format_error(error) == inspect(:boom)
+    end
+
+    test "returns a localized message for an Ash.Error.Forbidden" do
+      assert format_error(%Ash.Error.Forbidden{}) =~ "allowed"
+    end
+
+    test "passes through a plain binary unchanged" do
+      assert format_error("custom message") == "custom message"
+    end
+
+    test "returns a generic localized message for anything else" do
+      assert format_error(:unexpected) == "An error occurred"
+    end
+
+    test "renders the genuine update_member validation error as a user-facing message" do
+      system_actor = Mv.Helpers.SystemActor.get_system_actor()
+
+      {:ok, member} =
+        Mv.Membership.create_member(
+          %{
+            first_name: "Exit",
+            last_name: "Validation",
+            email: "exit-validation-#{System.unique_integer([:positive])}@example.com",
+            join_date: ~D[2024-01-01]
+          },
+          actor: system_actor
+        )
+
+      # exit_date earlier than join_date triggers the resource validation
+      {:error, %Ash.Error.Invalid{} = error} =
+        Mv.Membership.update_member(member, %{exit_date: ~D[2023-12-31]}, actor: system_actor)
+
+      formatted = format_error(error)
+
+      # The real Ash sub-error must surface its localized :message, not an inspect()'d struct.
+      assert formatted == "cannot be before join date"
+      refute formatted =~ "InvalidAttribute"
+      refute formatted =~ "%{"
+    end
+  end
+end