Vim, ALE and lightline-ale

ALE is a plugin for Vim 8 that provides linting while you edit, and where the linter in use supports autofixing ALE will do that for you too, or we can specify an alternate for the fixing. Read more about ALE here: https://github.com/w0rp/ale

The default linter for JSON is jsonlint, https://github.com/zaach/jsonlint, which doesn't come with any options to fix lint errors, but we can install fixjson to handle that for us https://github.com/rhysd/fixjson, all together:

npm install -g jsonlint fixjson

and in .vimrc:

let g:ale_fixers = {}
let g:ale_fixers['json'] = ['fixjson']

Another option here would be to use prettier, which lints and fixes, but that would be too easy, and defeat the purpose of this post; read more about prettier here https://github.com/prettier/prettier

This is incredibly useful to me as I spend a lot of time in JSON configs and whatnot, and in Vim I have auto lint fixing mapped to space d, so it's very simple to fix any errors, again in .vimrc:

" set the leader to <space>
:let mapleader = " " 
nmap <leader>d <Plug>(ale_fix)

Finally, as the cherry on the cake to all that, I have lightline.vim installed which adds some simple status line messages to my Vim window, https://github.com/itchyny/lightline.vim, and which also has available an ALE plugin to show lint status https://github.com/maximbaz/lightline-ale. Install as per the instructions in the link but note that the config should start with:

let g:lightline = {}

For more on the leader in Vim read http://learnvimscriptthehardway.stevelosh.com/chapters/06.html