Add benchmark for rendering record set list

bench/record_set_live_index.exs

@@ -0,0 +1,77 @@
+alias MusicLibrary.RecordSets
+alias MusicLibraryWeb.RecordSetLive
+alias Phoenix.LiveView.LiveStream
+
+Logger.configure(level: :error)
+
+# --- Data loading ---
+
+default_query = ""
+default_order = :updated_at
+default_page_size = 20
+
+total_sets = RecordSets.count_record_sets(default_query)
+
+sets =
+  RecordSets.search_record_sets(default_query,
+    offset: 0,
+    limit: default_page_size,
+    order: default_order
+  )
+
+# --- Assigns construction ---
+
+list_params = %{
+  page: 1,
+  page_size: default_page_size,
+  query: default_query,
+  order: default_order,
+  total_entries: total_sets,
+  total_pages: max(ceil(total_sets / default_page_size), 1)
+}
+
+empty_list_params = %{list_params | total_entries: 0, total_pages: 1}
+
+stream = LiveStream.new(:record_sets, "0", sets, [])
+empty_stream = LiveStream.new(:record_sets, "0", [], [])
+
+base_assigns = %{
+  __changed__: nil,
+  flash: %{},
+  current_section: :record_sets,
+  live_action: :index,
+  record_set: nil,
+  socket: %Phoenix.LiveView.Socket{
+    endpoint: MusicLibraryWeb.Endpoint,
+    router: MusicLibraryWeb.Router
+  }
+}
+
+assigns_with_data = Map.merge(base_assigns, %{list_params: list_params, streams: %{record_sets: stream}})
+assigns_empty = Map.merge(base_assigns, %{list_params: empty_list_params, streams: %{record_sets: empty_stream}})
+
+# --- Benchmark ---
+
+Benchee.run(
+  %{
+    "data loading (count + search)" =>
+      fn ->
+        total = RecordSets.count_record_sets(default_query)
+
+        RecordSets.search_record_sets(default_query,
+          offset: 0,
+          limit: default_page_size,
+          order: default_order
+        )
+
+        total
+      end,
+    "render/1 (default page, #{length(sets)} sets)" =>
+      fn -> RecordSetLive.Index.render(assigns_with_data) end,
+    "render/1 (empty)" =>
+      fn -> RecordSetLive.Index.render(assigns_empty) end
+  },
+  warmup: 2,
+  time: 5,
+  memory_time: 2
+)