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

test/mv_web/member_live/index_live_region_test.exs

@@ -0,0 +1,68 @@
+defmodule MvWeb.MemberLive.IndexLiveRegionTest do
+  @moduledoc """
+  §1.9 — The polite live region announces the exact total matching count,
+  computed via a count query for the active filter set.
+  §1.10 — The live region element exists in the DOM before it is filled, and the
+  table region carries `aria-busy`.
+  """
+  use MvWeb.ConnCase, async: false
+
+  import Phoenix.LiveViewTest
+
+  alias Mv.Helpers.SystemActor
+
+  defp seed(n) do
+    actor = SystemActor.get_system_actor()
+
+    Enum.each(1..n, fn i ->
+      idx = String.pad_leading(Integer.to_string(i), 3, "0")
+
+      {:ok, _} =
+        Mv.Membership.create_member(
+          %{first_name: "Lr#{idx}", last_name: "Region", email: "lr#{idx}@example.com"},
+          actor: actor
+        )
+    end)
+  end
+
+  test "polite live region exists on first render and announces the exact total", %{conn: conn} do
+    seed(60)
+    conn = conn_with_oidc_user(conn)
+    {:ok, view, _html} = live(conn, ~p"/members")
+
+    # Present-before-fill: the live region element is in the initial DOM.
+    assert has_element?(view, "#members-result-count[aria-live='polite']")
+    # Exact total, not the loaded page size (60 matched, only 50 loaded).
+    region = view |> element("#members-result-count") |> render()
+    assert region =~ "60 members"
+  end
+
+  test "table region binds aria-busy to the loading flag (settled after load)", %{conn: conn} do
+    conn = conn_with_oidc_user(conn)
+    {:ok, view, _html} = live(conn, ~p"/members")
+
+    # aria-busy is bound to @loading? (`to_string(@loading?)`), not hardcoded: once
+    # the page has loaded the region is not busy. It is set true across a
+    # filter/sort/search reload patch (push_reload/2, §1.10).
+    assert has_element?(view, "[data-testid='members-table-scroll'][aria-busy='false']")
+  end
+
+  test "count reflects the active filter set, not the whole table", %{conn: conn} do
+    actor = SystemActor.get_system_actor()
+
+    {:ok, _} =
+      Mv.Membership.create_member(
+        %{first_name: "Findme", last_name: "Unique", email: "findme@example.com"},
+        actor: actor
+      )
+
+    seed(5)
+    conn = conn_with_oidc_user(conn)
+    {:ok, view, _html} = live(conn, ~p"/members?query=Findme")
+
+    # Only the single matching member is counted (1 of 6 total).
+    region = view |> element("#members-result-count") |> render()
+    assert region =~ "1 member"
+    refute region =~ "6 member"
+  end
+end