Before:
    " Switch to the test rails directory.
    let b:path = getcwd()
    silent! cd /testplugin/test/handler
    cd ../ruby_fixtures/valid_rails_app/app/models

    runtime ale_linters/ruby/rails_best_practices.vim

After:
    " Switch back to whatever directory it was that we started on.
    silent! 'cd ' . fnameescape(b:path)
    unlet! b:path

    call ale#linter#Reset()

Execute(The rails_best_practices handler should parse JSON correctly):
  silent file! thing.rb

  AssertEqual
  \  [
  \      {
  \          'lnum': 5,
  \          'text': 'use local variable',
  \          'type': 'W',
  \      },
  \      {
  \          'lnum': 10,
  \          'text': 'other advice',
  \          'type': 'W',
  \      }
  \  ],
  \  ale_linters#ruby#rails_best_practices#Handle(bufnr(''), [
  \  '[',
  \    '{',
  \      '"message": "use local variable",',
  \      '"line_number": "5",',
  \      '"filename": "/testplugin/test/ruby_fixtures/valid_rails_app/app/models/thing.rb"',
  \    '},{',
  \      '"message": "other advice",',
  \      '"line_number": "10",',
  \      '"filename": "/testplugin/test/ruby_fixtures/valid_rails_app/app/models/thing.rb"',
  \    '}',
  \  ']'
  \  ])

Execute(The rails_best_practices handler should parse JSON correctly when there is no output from the tool):
  AssertEqual
  \ [],
  \ ale_linters#ruby#rails_best_practices#Handle(347, [
  \ ])