Add to your .vimrc file:
function! GnoFmt()
cexpr system('gofmt -e -w ' . expand('%')) "or replace with gofumpt
edit!
endfunction
command! GnoFmt call GnoFmt()
augroup gno_autocmd
autocmd!
autocmd BufNewFile,BufRead *.gno set filetype=go
autocmd BufWritePost *.gno GnoFmt
augroup END
TODO: other vim tweaks to make work with vim-go etc.
Install go-mode.el.
Add to your emacs configuration file:
(add-to-list 'auto-mode-alist '("\\.gno\\'" . go-mode))