Prevent ALE from linting diffs

[bdielman]

I use Vim as my diff and merge tool for Git. When running Gdiff in a file in Vim, I get the split window with diffs displayed with no issues (linting). When I run the difftool alias for Git from the command line, it opens up a similar split, but this time index version of the file is pulling from a temp directory /private/vars/folder and ALE lints the file. It seems that because this file is outside of the repo it doesn't use the rubocop config and seems to pull from a default set of rules.

Ideally, ALE wouldn't lint files when viewed via vimdiff or Gdiff.

[w0rp]

Do you know if there's some way to detect if a Vim buffer is a buffer being used for displaying diffs with common plugins?

[bdielman]

Not that I can see, but I'm still looking into it.

[resolritter]

gina.vim uses &diff

https://github.com/lambdalisue/gina.vim/blob/master/autoload/gina/util.vim#L233

fugitive seems to do the same
https://github.com/tpope/vim-fugitive/blob/master/autoload/fugitive.vim#L3433

[resolritter]

as an extra for gina, it also uses file protocols gina://* and custom filetypes for all of its views (that I know of)

[Christian-Gibbons]

I have an autocommand in my vimrc to at least not open up the loclist for a diff. It's probably not a perfect solution, but it might give you an idea of what to do.

   augroup ale
      autocmd VimEnter * if(&diff) | let g:ale_open_list = 0 | endif
   augroup END

[w0rp]

git pull and try it again. ALE should now avoid checking buffers where &diff is set.