pull down from top alacritty (like iTerm2)

alacritty.yml

window:
  # Window dimensions (changes require restart)
  #
  # Number of lines/columns (not pixels) in the terminal. The number of columns
  # must be at least `2`, while using a value of `0` for columns and lines will
  # fall back to the window manager's recommended size.
  dimensions:
    columns: 500
    lines: 30

  # Window position (changes require restart)
  #
  # Specified in number of pixels.
  # If the position is not set, the window manager will handle the placement.
  position:
    x: 0
    y: 0

  # Window padding (changes require restart)
  #
  # Blank space added around the window in pixels. This padding is scaled
  # by DPI and the specified value is always added at both opposing sides.
  #padding:
  #  x: 0
  #  y: 0

  # Spread additional padding evenly around the terminal content.
  #dynamic_padding: false

  # Window decorations
  #
  # Values for `decorations`:
  #     - full: Borders and title bar
  #     - none: Neither borders nor title bar
  #
  # Values for `decorations` (macOS only):
  #     - transparent: Title bar, transparent background and title bar buttons
  #     - buttonless: Title bar, transparent background and no title bar buttons
  decorations: none
  
key_bindings:
  - { key: Return,          mods: Command,                    action: ToggleSimpleFullscreen }

init.lua

local spaces = require('hs._asm.undocumented.spaces') -- https://github.com/asmagill/hs._asm.undocumented.spaces

-- Switch alacritty
hs.hotkey.bind({'alt'}, 'space', function ()
  local APP_NAME = 'Alacritty'
  function moveWindow(alacritty, space, mainScreen)
    -- move to main space
    local win = nil
    while win == nil do
      win = alacritty:mainWindow()
    end
    print(win)
    print(space)
    print(win:screen())
    print(mainScreen)
    local fullScreen = not win:isStandard()
    if fullScreen then
      hs.eventtap.keyStroke('cmd', 'return', 0, alacritty)
    end
    winFrame = win:frame()
    scrFrame = mainScreen:fullFrame()
    print(winFrame)
    print(scrFrame)
    winFrame.w = scrFrame.w
    winFrame.y = scrFrame.y
    winFrame.x = scrFrame.x
    print(winFrame)
    win:setFrame(winFrame, 0)
    print(win:frame())
    win:spacesMoveTo(space)
    if fullScreen then
      hs.eventtap.keyStroke('cmd', 'return', 0, alacritty)
    end
    win:focus()
  end
  local alacritty = hs.application.get(APP_NAME)
  if alacritty ~= nil and alacritty:isFrontmost() then
    alacritty:hide()
  else
    local space = spaces.activeSpace()
    local mainScreen = hs.screen.find(spaces.mainScreenUUID())
    if alacritty == nil and hs.application.launchOrFocus(APP_NAME) then
      local appWatcher = nil
      print('create app watcher')
      appWatcher = hs.application.watcher.new(function(name, event, app)
        print(name)
        print(event)
        if event == hs.application.watcher.launched and name == APP_NAME then
          app:hide()
          moveWindow(app, space, mainScreen)
          appWatcher:stop()
        end
      end)
      print('start watcher')
      appWatcher:start()
    end
    if alacritty ~= nil then
      moveWindow(alacritty, space, mainScreen)
    end
  end
end)

I have rewrite this script to use latest hs.spaces module, and replace get app_name to get bundle id to avoid mismatching with browser title and I works fine with hammerspoon Version 0.9.100(6815):
check my fork for details: https://gist.github.com/truebit/31396bb2f48c75285d724c9e9e037bcd

And here is the Kitty implementation: https://gist.github.com/truebit/d79b8018666d65e95970f208d8f5d149