Use with auto-sessions breaks beacon.

[BerkeleyTrue]

I use rmagatti/auto-session to manage nvim sessions. Beacon seems to work great without a fresh session, but when ever resuming a session beacon throws errors due to invalid buffer ids

Error executing vim.schedule lua callback: ...eytrue/.local/share/nvim/lazy/beacon.nvim/lua/beacon.lua:38: Invalid buffer id: 2
stack traceback:
	[C]: in function 'nvim_open_win'
	...eytrue/.local/share/nvim/lazy/beacon.nvim/lua/beacon.lua:38: in function 'create_window'
	...eytrue/.local/share/nvim/lazy/beacon.nvim/lua/beacon.lua:76: in function <...eytrue/.local/share/nvim/lazy/beacon.nvim/lua/beacon.lua:56>

Maybe a race condition? Maybe auto-session is removing buffers that don't exist in the session?

[f-leeske]

The problem is the incorrect buffer id of beacon's fake buffer that it uses to play the animation, in beacon.lua, l.31:

local fake_buffer = vim.api.nvim_create_buf(false, true)

local function create_window(cfg)
  local window = vim.api.nvim_open_win(fake_buffer, false, {  -- <-- fake_buffer is off if session was loaded with at least one buffer
    relative = 'cursor',
    row = 0,
    col = 0,
    width = cfg.width,
    height = 1,
    style = 'minimal',
    focusable = false,
    noautocmd = true,
  })

My workaround is to lazy-load beacon on the "CursorMoved" event, and I haven't encountered any issues so far:

return {
    "danilamihailov/beacon.nvim",
    event = "CursorMoved",
}