😂 Emojimode for Neovim 0.10+ 😂 (Run with `:Emojimode`)

emojimode.lua

local api = vim.api

local is_on = false
local emoji_width = api.nvim_strwidth "😂"
local ns = api.nvim_create_namespace "emojimode"

api.nvim_create_user_command("Emojimode", function()
  is_on = not is_on

  api.nvim_set_decoration_provider(ns, {

    on_win = is_on and function(_, win, buf, topline, botline)
      for line = topline, botline do
        local line_display_len = vim.fn.virtcol({ line + 1, "$" }, 0, win)

        api.nvim_buf_set_extmark(buf, ns, line, 0, {
          ephemeral = true,
          virt_text_pos = "overlay",
          virt_text = { { ("😂"):rep(line_display_len / emoji_width) } },
        })
      end
    end or nil,
  })
end, {})