Add JSON fixer using 'python -m json.tool'

[Konstantin-Glukhov]

Implement something similar to the following code:

ftplugin/json.vim:

let b:ale_fixers = ['json_python_fixer] let b:ale_json_python_fixer_options = '--indent 2'

autoload/ale/fixers/json_python_fixer.vim:

" Description: Fix JSON files with "python -m json.tool"
call ale#Set('json_python_fixer_options', '')

function! ale#fixers#json_python_fixer#Fix(buffer) abort
  let l:command = 'python'

  if !executable(l:command)
    echo 'ALEFix: ' . l:command . ' executable not found'
    return {'command': 'REM'}
  endif

  let l:command .= ' -m json.tool'

  let l:options = ale#Var(a:buffer, 'json_python_fixer_options')
  if len(l:options)
    let l:command .= ' ' . l:options
  endif

  return { 'command': l:command . ' -'}
endfunction

[idbrii]

A big advantage of json.tool over alternatives like jsbeautify is that you can sort the keys:

let g:ale_json_python_fixer_options = '--sort-keys'