function test_resize_window()
  App.resize(200, 400)
  -- ugly; resize switches to real, non-test margins
  -- TODO: how to make assertions about when App.update got past the early exit?
end
  check_eq(App.screen.width, 200, 'width')
  check_eq(App.screen.height, 400, 'height')
  check_eq(Editor_state.left, Margin_left, 'left_margin')
  check_eq(Editor_state.right, 200-Margin_right, 'right_margin')
  check_eq(Editor_state.width, 200-Margin_left-Margin_right, 'drawing_width')
  App.screen.init{width=300, height=300}
  Editor_state.filename = 'foo'
  check_eq(App.screen.width, 300, 'baseline/width')
  check_eq(App.screen.height, 300, 'baseline/height')
  check_eq(Editor_state.left, Test_margin_left, 'baseline/left_margin')
  check_eq(Editor_state.right, 300 - Test_margin_right, 'baseline/left_margin')
  Editor_state = edit.initialize_test_state()

  -- maximizing on iOS breaks text rendering: https://github.com/deltadaedalus/vudu/issues/7
  -- no point second-guessing window dimensions on mobile
  App.screen.width, App.screen.height, App.screen.flags = App.screen.size()

  -- determine default dimensions and flags
  App.screen.width, App.screen.height, App.screen.flags = App.screen.size()
  -- set up desired window dimensions
  App.screen.flags.resizable = true
  App.screen.flags.minwidth = math.min(App.screen.width, 200)
  App.screen.flags.minheight = math.min(App.screen.height, 200)
  App.screen.width, App.screen.height = Settings.width, Settings.height
  App.screen.resize(App.screen.width, App.screen.height, App.screen.flags)
  App.screen.move(Settings.x, Settings.y, Settings.displayindex)

  run.initialize_window_geometry(App.width(em))

function run.initialize_window_geometry(em_width)
  local os = love.system.getOS()
  if os == 'Android' or os == 'iOS' then
    -- maximizing on iOS breaks text rendering: https://github.com/deltadaedalus/vudu/issues/7
    -- no point second-guessing window dimensions on mobile
    App.screen.width, App.screen.height, App.screen.flags = App.screen.size()
    return
  end
  -- maximize window
  App.screen.resize(0, 0)  -- maximize
  App.screen.width, App.screen.height, App.screen.flags = App.screen.size()
  -- shrink height slightly to account for window decoration
  App.screen.height = App.screen.height-100
  App.screen.width = 40*em_width
  App.screen.flags.resizable = true
  App.screen.flags.minwidth = math.min(App.screen.width, 200)
  App.screen.flags.minheight = math.min(App.screen.height, 200)
  App.screen.resize(App.screen.width, App.screen.height, App.screen.flags)
end
function run.resize(w, h)
--?   print(("Window resized to width: %d and height: %d."):format(w, h))
  App.screen.width, App.screen.height = w, h
  Text.redraw_all(Editor_state)
  Editor_state.selection1 = {}  -- no support for shift drag while we're resizing
  Editor_state.right = App.screen.width-Margin_right
  Editor_state.width = Editor_state.right-Editor_state.left
  Text.tweak_screen_top_and_cursor(Editor_state, Editor_state.left, Editor_state.right)
end

    x=Settings.x, y=Settings.y, displayindex=Settings.displayindex,
    width=App.screen.width, height=App.screen.height,

    load_file_from_source_or_save_directory('run_tests.lua')