see screenshot here, is it possible to set a max width of the float window here?
answering my own question. We can config float window opened by lsp using following code. more configuration available via :h vim.lsp.util.open_floating_preview
local orig_util_open_floating_preview = vim.lsp.util.open_floating_preview
function vim.lsp.util.open_floating_preview(contents, syntax, opts, ...)
opts = opts or {}
opts.border = opts.border or 'single'
opts.max_width= opts.max_width or 80
return orig_util_open_floating_preview(contents, syntax, opts, ...)
end