feat(member): stream the overview with keyset infinite scroll instead of loading every member

test/mv_web/member_live/index_test.exs

@@ -306,7 +306,8 @@ defmodule MvWeb.MemberLive.IndexTest do
     # asserted on internal state to preserve the original coverage of the callback.
     assigns = :sys.get_state(view.pid).socket.assigns
     assert assigns.query == "Friedrich"
-    assert is_list(assigns.members)
+    # Loaded members are held as a `%{id => member}` map (the restream lookup window).
+    assert is_map(assigns.members)
   end
 
   @tag :ui
@@ -1069,6 +1070,63 @@ defmodule MvWeb.MemberLive.IndexTest do
       assert bcc =~ "scope1%40example.com"
       refute bcc =~ "scope2%40example.com"
     end
+
+    test "selecting a member does not read the DB for mailto recipients (deferred to open)",
+         %{conn: conn, member1: member1} do
+      conn = conn_with_oidc_user(conn)
+      {:ok, view, _html} = live(conn, "/members")
+
+      # A checkbox toggle is a non-search interaction; it must not issue a member
+      # read just to precompute a mailto link the user may never open. The
+      # recipient list is fetched lazily when the bulk-actions dropdown opens.
+      member_reads =
+        capture_member_select_queries(fn ->
+          render_click(view, "select_member", %{"id" => member1.id})
+        end)
+
+      assert member_reads == [],
+             "select_member must not read members for the mailto recipients; got: #{inspect(member_reads)}"
+
+      # Opening the dropdown still surfaces the correct recipients for the selection.
+      bcc = mailto_bcc(view)
+      assert bcc =~ "scope1%40example.com"
+      refute bcc =~ "scope2%40example.com"
+    end
+
+    # Captures every SELECT against the members table emitted while `fun` runs.
+    defp capture_member_select_queries(fun) do
+      test_pid = self()
+      handler_id = "test-member-select-#{System.unique_integer([:positive])}"
+
+      :telemetry.attach(
+        handler_id,
+        [:mv, :repo, :query],
+        fn _event, _measurements, metadata, _config ->
+          sql = metadata[:query] || ""
+
+          if String.contains?(sql, "SELECT") and String.contains?(sql, "\"members\"") do
+            send(test_pid, {:member_query, sql})
+          end
+        end,
+        nil
+      )
+
+      try do
+        fun.()
+      after
+        :telemetry.detach(handler_id)
+      end
+
+      collect_member_queries([])
+    end
+
+    defp collect_member_queries(acc) do
+      receive do
+        {:member_query, sql} -> collect_member_queries([sql | acc])
+      after
+        0 -> Enum.reverse(acc)
+      end
+    end
   end
 
   describe "cycle status filter" do
@@ -2372,12 +2430,12 @@ defmodule MvWeb.MemberLive.IndexTest do
       # Should complete in less than 1 second (1000ms)
       assert duration < 1000, "Filter took #{duration}ms, expected < 1000ms"
 
-      # Verify filtering worked correctly - should show all true members
-      Enum.each(1..75, fn i ->
-        assert html =~ "TrueMember#{i}"
-      end)
+      # The overview now keyset-paginates: mount loads only the first page, not
+      # the whole filtered set (§1.7). The filter still resolves DB-side, so the
+      # loaded page contains only matching (true) members and never a non-matching
+      # (false) one.
+      assert html =~ "TrueMember"
 
-      # Should not show false members
       Enum.each(1..75, fn i ->
         refute html =~ "FalseMember#{i}"
       end)