Ensure user toggles on board edit page are cached properly

Not including the disabled flag as part of the cache resulted in
issues like the one described in #1992

test/controllers/boards_controller_test.rb

@@ -166,4 +166,28 @@ class BoardsControllerTest < ActionDispatch::IntegrationTest
     assert_select "button:not([disabled])", text: "Select all"
     assert_select "button:not([disabled])", text: "Select none"
   end
+
+  test "access toggle disabled state is cached correctly" do
+    board = boards(:writebook)
+    david = users(:david)
+
+    with_actionview_partial_caching do
+      # privileged user
+      assert users(:kevin).can_administer_board?(board)
+
+      get edit_board_path(board)
+
+      assert_response :success
+      assert_select "input.switch__input[name='user_ids[]'][value='#{david.id}']:not([disabled])"
+
+      # unprivileged user
+      logout_and_sign_in_as :jz
+      assert_not users(:jz).can_administer_board?(board)
+
+      get edit_board_path(board)
+
+      assert_response :success
+      assert_select "input.switch__input[name='user_ids[]'][value='#{david.id}'][disabled]"
+    end
+  end
 end