CheckHealth

- Use execute() instead of redir
- Fixed logic on suboptimal pyenv/virtualenv checks.
- Move system calls from strings to lists. Fixes #5218
- Add highlighting
- Automatically discover health checkers
- Add tests

Helped-by: Shougo Matsushita <Shougo.Matsu@gmail.com>
Helped-by: Tommy Allen <tommy@esdf.io>

Closes #4932

7 files changed, 821 insertions, 446 deletions

diff --git a/runtime/autoload/health.vim b/runtime/autoload/health.vim
index 0a698e6492..edcb3d792d 100644
--- a/runtime/autoload/health.vim
+++ b/runtime/autoload/health.vim
@@ -1,468 +1,199 @@
-function! s:trim(s) abort
-  return substitute(a:s, '^\_s*\|\_s*$', '', 'g')
-endfunction
-
-
-" Simple version comparison.
-function! s:version_cmp(a, b) abort
-  let a = split(a:a, '\.')
-  let b = split(a:b, '\.')
-
-  for i in range(len(a))
-    if a[i] > b[i]
-      return 1
-    elseif a[i] < b[i]
-      return -1
-    endif
-  endfor
-
-  return 0
-endfunction
-
-
-" Fetch the contents of a URL.
-function! s:download(url) abort
-  let content = ''
-  if executable('curl')
-    let content = system('curl -sL "'.a:url.'"')
-  endif
-
-  if empty(content) && executable('python')
-    let script = "
-          \try:\n
-          \    from urllib.request import urlopen\n
-          \except ImportError:\n
-          \    from urllib2 import urlopen\n
-          \\n
-          \try:\n
-          \    response = urlopen('".a:url."')\n
-          \    print(response.read().decode('utf8'))\n
-          \except Exception:\n
-          \    pass\n
-          \"
-    let content = system('python -c "'.script.'" 2>/dev/null')
-  endif
-
-  return content
-endfunction
-
-
-" Get the latest Neovim Python client version from PyPI.  The result is
-" cached.
-function! s:latest_pypi_version()
-  if exists('s:pypi_version')
-    return s:pypi_version
-  endif
-
-  let s:pypi_version = 'unknown'
-  let pypi_info = s:download('https://pypi.python.org/pypi/neovim/json')
-  if !empty(pypi_info)
-    let pypi_data = json_decode(pypi_info)
-    let s:pypi_version = get(get(pypi_data, 'info', {}), 'version', 'unknown')
-    return s:pypi_version
-  endif
-endfunction
-
-
-" Get version information using the specified interpreter.  The interpreter is
-" used directly in case breaking changes were introduced since the last time
-" Neovim's Python client was updated.
-function! s:version_info(python) abort
-  let pypi_version = s:latest_pypi_version()
-  let python_version = s:trim(system(
-        \ printf('"%s" -c "import sys; print(''.''.join(str(x) '
-        \ . 'for x in sys.version_info[:3]))"', a:python)))
-  if empty(python_version)
-    let python_version = 'unknown'
-  endif
-  
-  let nvim_path = s:trim(system(printf('"%s" -c "import sys, neovim;'
-        \ . 'print(neovim.__file__)" 2>/dev/null', a:python)))
-  if empty(nvim_path)
-    return [python_version, 'not found', pypi_version, 'unknown']
-  endif
-
-  let nvim_version = 'unknown'
-  let base = fnamemodify(nvim_path, ':h')
-  for meta in glob(base.'-*/METADATA', 1, 1) + glob(base.'-*/PKG-INFO', 1, 1)
-    for meta_line in readfile(meta)
-      if meta_line =~# '^Version:'
-        let nvim_version = matchstr(meta_line, '^Version: \zs\S\+')
-      endif
-    endfor
-  endfor
-
-  let version_status = 'unknown'
-  if nvim_version != 'unknown' && pypi_version != 'unknown'
-    if s:version_cmp(nvim_version, pypi_version) == -1
-      let version_status = 'outdated'
-    else
-      let version_status = 'up to date'
-    endif
-  endif
-
-  return [python_version, nvim_version, pypi_version, version_status]
-endfunction
-
-
-" Check the Python interpreter's usability.
-function! s:check_bin(bin, notes) abort
-  if !filereadable(a:bin)
-    call add(a:notes, printf('Error: "%s" was not found.', a:bin))
-    return 0
-  elseif executable(a:bin) != 1
-    call add(a:notes, printf('Error: "%s" is not executable.', a:bin))
-    return 0
-  endif
-  return 1
-endfunction
-
-
-" Text wrapping that returns a list of lines
-function! s:textwrap(text, width) abort
-  let pattern = '.*\%(\s\+\|\_$\)\zs\%<'.a:width.'c'
-  return map(split(a:text, pattern), 's:trim(v:val)')
-endfunction
-
+" Dictionary where we keep all of the healtch check functions we've found.
+" They will only be run if the value is true
+let g:health_checkers = get(g:, 'health_checkers', {})
+let s:current_checker = get(s:, 'current_checker', '')
+
+""
+" Function to run the health checkers
+" It manages the output and any file local settings
+function! health#check(bang) abort
+  let l:report = '# Checking health'
 
-" Echo wrapped notes
-function! s:echo_notes(notes) abort
-  if empty(a:notes)
-    return
+  if g:health_checkers == {}
+    call health#add_checker(s:_default_checkers())
   endif
 
-  echo '  Messages:'
-  for msg in a:notes
-    if msg =~# "\n"
-      let msg_lines = []
-      for msgl in filter(split(msg, "\n"), 'v:val !~# ''^\s*$''')
-        call extend(msg_lines, s:textwrap(msgl, 74))
-      endfor
-    else
-      let msg_lines = s:textwrap(msg, 74)
-    endif
+  for l:checker in items(g:health_checkers)
+    " Disabled checkers will not run their registered check functions
+    if l:checker[1]
+      let s:current_checker = l:checker[0]
+      let l:report .= "\n\n--------------------------------------------------------------------------------\n"
+      let l:report .= printf("\n## Checker %s says:\n", s:current_checker)
 
-    if !len(msg_lines)
-      continue
-    endif
-    echo '    *' msg_lines[0]
-    if len(msg_lines) > 1
-      echo join(map(msg_lines[1:], '"      ".v:val'), "\n")
+      let l:report .= capture('call ' . l:checker[0] . '()')
     endif
   endfor
-endfunction
-
-
-" Load the remote plugin manifest file and check for unregistered plugins
-function! s:diagnose_manifest() abort
-  echo 'Checking: Remote Plugins'
-  let existing_rplugins = {}
-
-  for item in remote#host#PluginsForHost('python')
-    let existing_rplugins[item.path] = 'python'
-  endfor
-
-  for item in remote#host#PluginsForHost('python3')
-    let existing_rplugins[item.path] = 'python3'
-  endfor
 
-  let require_update = 0
-  let notes = []
+  let l:report .= "\n--------------------------------------------------------------------------------\n"
 
-  for path in map(split(&rtp, ','), 'resolve(v:val)')
-    let python_glob = glob(path.'/rplugin/python*', 1, 1)
-    if empty(python_glob)
-      continue
-    endif
-
-    let python_dir = python_glob[0]
-    let python_version = fnamemodify(python_dir, ':t')
-
-    for script in glob(python_dir.'/*.py', 1, 1)
-          \ + glob(python_dir.'/*/__init__.py', 1, 1)
-      let contents = join(readfile(script))
-      if contents =~# '\<\%(from\|import\)\s\+neovim\>'
-        if script =~# '/__init__\.py$'
-          let script = fnamemodify(script, ':h')
-        endif
-
-        if !has_key(existing_rplugins, script)
-          let msg = printf('"%s" is not registered.', fnamemodify(path, ':t'))
-          if python_version == 'pythonx'
-            if !has('python2') && !has('python3')
-              let msg .= ' (python2 and python3 not available)'
-            endif
-          elseif !has(python_version)
-            let msg .= printf(' (%s not available)', python_version)
-          else
-            let require_update = 1
-          endif
-
-          call add(notes, msg)
-        endif
-
-        break
-      endif
-    endfor
-  endfor
-
-  echo '  Status: '
-  if require_update
-    echon 'Out of date'
-    call add(notes, 'Run :UpdateRemotePlugins')
+  if a:bang
+    new
+    setlocal bufhidden=wipe
+    set syntax=health
+    set filetype=health
+    call setline(1, split(report, "\n"))
+    setlocal nomodified
   else
-    echon 'Up to date'
+    echo report
+    echo "\nTip: Use "
+    echohl Identifier
+    echon ':CheckHealth!'
+    echohl None
+    echon ' to open this in a new buffer.'
   endif
-
-  call s:echo_notes(notes)
 endfunction
 
-
-function! s:diagnose_python(version) abort
-  let python_bin_name = 'python'.(a:version == 2 ? '' : '3')
-  let pyenv = resolve(exepath('pyenv'))
-  let pyenv_root = exists('$PYENV_ROOT') ? resolve($PYENV_ROOT) : ''
-  let venv = exists('$VIRTUAL_ENV') ? resolve($VIRTUAL_ENV) : ''
-  let host_prog_var = python_bin_name.'_host_prog'
-  let host_skip_var = python_bin_name.'_host_skip_check'
-  let python_bin = ''
-  let python_multiple = []
-  let notes = []
-
-  if exists('g:'.host_prog_var)
-    call add(notes, printf('Using: g:%s = "%s"', host_prog_var, get(g:, host_prog_var)))
-  endif
-
-  let [python_bin_name, pythonx_errs] = provider#pythonx#Detect(a:version)
-  if empty(python_bin_name)
-    call add(notes, 'Warning: No Python interpreter was found with the neovim '
-          \ . 'module.  Using the first available for diagnostics.')
-    if !empty(pythonx_errs)
-      call add(notes, pythonx_errs)
-    endif
-    let old_skip = get(g:, host_skip_var, 0)
-    let g:[host_skip_var] = 1
-    let [python_bin_name, pythonx_errs] = provider#pythonx#Detect(a:version)
-    let g:[host_skip_var] = old_skip
-  endif
-
-  if !empty(python_bin_name)
-    if exists('g:'.host_prog_var)
-      let python_bin = exepath(python_bin_name)
-    endif
-    let python_bin_name = fnamemodify(python_bin_name, ':t')
-  endif
-
-  if !empty(pythonx_errs)
-    call add(notes, pythonx_errs)
-  endif
-
-  if !empty(python_bin_name) && empty(python_bin) && empty(pythonx_errs)
-    if !exists('g:'.host_prog_var)
-      call add(notes, printf('Warning: "g:%s" is not set.  Searching for '
-            \ . '%s in the environment.', host_prog_var, python_bin_name))
-    endif
-
-    if !empty(pyenv)
-      if empty(pyenv_root)
-        call add(notes, 'Warning: pyenv was found, but $PYENV_ROOT '
-              \ . 'is not set.  Did you follow the final install '
-              \ . 'instructions?')
-      else
-        call add(notes, printf('Notice: pyenv found: "%s"', pyenv))
-      endif
-
-      let python_bin = s:trim(system(
-            \ printf('"%s" which %s 2>/dev/null', pyenv, python_bin_name)))
-
-      if empty(python_bin)
-        call add(notes, printf('Warning: pyenv couldn''t find %s.', python_bin_name))
-      endif
-    endif
-
-    if empty(python_bin)
-      let python_bin = exepath(python_bin_name)
-
-      if exists('$PATH')
-        for path in split($PATH, ':')
-          let path_bin = path.'/'.python_bin_name
-          if path_bin != python_bin && index(python_multiple, path_bin) == -1
-                \ && executable(path_bin)
-            call add(python_multiple, path_bin)
-          endif
-        endfor
-
-        if len(python_multiple)
-          " This is worth noting since the user may install something
-          " that changes $PATH, like homebrew.
-          call add(notes, printf('Suggestion: There are multiple %s executables found.  '
-                \ . 'Set "g:%s" to avoid surprises.', python_bin_name, host_prog_var))
-        endif
-
-        if python_bin =~# '\<shims\>'
-          call add(notes, printf('Warning: "%s" appears to be a pyenv shim.  '
-                \ . 'This could mean that a) the "pyenv" executable is not in '
-                \ . '$PATH, b) your pyenv installation is broken.  '
-                \ . 'You should set "g:%s" to avoid surprises.',
-                \ python_bin, host_prog_var))
-        endif
-      endif
+" Report functions {{{
+
+""
+" Start a report section.
+" It should represent a general area of tests that can be understood
+" from the argument {name}
+" To start a new report section, use this function again
+function! health#report_start(name) abort " {{{
+  echo '  - Checking: ' . a:name
+endfunction " }}}
+
+""
+" Format a message for a specific report item
+function! s:format_report_message(status, msg, ...) abort " {{{
+  let l:output = '    - ' . a:status . ': ' . a:msg
+
+  " Check optional parameters
+  if a:0 > 0
+    " Suggestions go in the first optional parameter can be a string or list
+    if type(a:1) == type("")
+      let l:output .= "\n      - SUGGESTIONS:"
+      let l:output .= "\n        - " . a:1
+    elseif type(a:1) == type([])
+      " Report each suggestion
+      let l:output .= "\n      - SUGGESTIONS:"
+      for l:suggestion in a:1
+        let l:output .= "\n        - " . l:suggestion
+      endfor
+    else
+      echoerr "A string or list is required as the optional argument for suggestions"
     endif
   endif
 
-  if !empty(python_bin)
-    if !empty(pyenv) && !exists('g:'.host_prog_var) && !empty(pyenv_root)
-          \ && resolve(python_bin) !~# '^'.pyenv_root.'/'
-      call add(notes, printf('Suggestion: Create a virtualenv specifically '
-            \ . 'for Neovim using pyenv and use "g:%s".  This will avoid '
-            \ . 'the need to install Neovim''s Python client in each '
-            \ . 'version/virtualenv.', host_prog_var))
-    endif
+  return output
+endfunction " }}}
 
-    if !empty(venv) && exists('g:'.host_prog_var)
-      if !empty(pyenv_root)
-        let venv_root = pyenv_root
-      else
-        let venv_root = fnamemodify(venv, ':h')
-      endif
+""
+" Use {msg} to report information in the current section
+function! health#report_info(msg) abort " {{{
+  echo s:format_report_message('INFO', a:msg)
+endfunction " }}}
 
-      if resolve(python_bin) !~# '^'.venv_root.'/'
-        call add(notes, printf('Suggestion: Create a virtualenv specifically '
-              \ . 'for Neovim and use "g:%s".  This will avoid '
-              \ . 'the need to install Neovim''s Python client in each '
-              \ . 'virtualenv.', host_prog_var))
-      endif
-    endif
-  endif
+""
+" Use {msg} to represent the check that has passed
+function! health#report_ok(msg) abort " {{{
+  echo s:format_report_message('SUCCESS', a:msg)
+endfunction " }}}
 
-  if empty(python_bin) && !empty(python_bin_name)
-    " An error message should have already printed.
-    call add(notes, printf('Error: "%s" was not found.', python_bin_name))
-  elseif !empty(python_bin) && !s:check_bin(python_bin, notes)
-    let python_bin = ''
+""
+" Use {msg} to represent a failed health check and optionally a list of suggestions on how to fix it.
+function! health#report_warn(msg, ...) abort " {{{
+  if a:0 > 0 && type(a:1) == type([])
+    echo s:format_report_message('WARNING', a:msg, a:1)
+  else
+    echo s:format_report_message('WARNING', a:msg)
   endif
+endfunction " }}}
 
-  " Check if $VIRTUAL_ENV is active
-  let virtualenv_inactive = 0
-
-  if exists('$VIRTUAL_ENV')
-    if !empty(pyenv)
-      let pyenv_prefix = resolve(s:trim(system(printf('"%s" prefix', pyenv))))
-      if $VIRTUAL_ENV != pyenv_prefix
-        let virtualenv_inactive = 1
-      endif
-    elseif !empty(python_bin_name) && exepath(python_bin_name) !~# '^'.$VIRTUAL_ENV.'/'
-      let virtualenv_inactive = 1
-    endif
+""
+" Use {msg} to represent a critically failed health check and optionally a list of suggestions on how to fix it.
+function! health#report_error(msg, ...) abort " {{{
+  if a:0 > 0 && type(a:1) == type([])
+    echo s:format_report_message('ERROR', a:msg, a:1)
+  else
+    echo s:format_report_message('ERROR', a:msg)
   endif
+endfunction " }}}
 
-  if virtualenv_inactive
-    call add(notes, 'Warning: $VIRTUAL_ENV exists but appears to be '
-          \ . 'inactive.  This could lead to unexpected results.  If you are '
-          \ . 'using Zsh, see: http://vi.stackexchange.com/a/7654/5229')
-  endif
+" }}}
+" Health checker management {{{
 
-  " Diagnostic output
-  echo 'Checking: Python' a:version
-  echo '  Executable:' (empty(python_bin) ? 'Not found' : python_bin)
-  if len(python_multiple)
-    for path_bin in python_multiple
-      echo '     (other):' path_bin
+""
+" Add a single health checker
+" It does not modify any values if the checker already exists
+function! s:add_single_checker(checker_name) abort " {{{
+  if has_key(g:health_checkers, a:checker_name)
+    return
+  else
+      let g:health_checkers[a:checker_name] = v:true
+  endif
+endfunction " }}}
+
+""
+" Enable a single health checker
+" It will modify the values if the checker already exists
+function! s:enable_single_checker(checker_name) abort " {{{
+  let g:health_checkers[a:checker_name] = v:true
+endfunction " }}}
+
+""
+" Disable a single health checker
+" It will modify the values if the checker already exists
+function! s:disable_single_checker(checker_name) abort " {{{
+  let g:health_checkers[a:checker_name] = v:false
+endfunction " }}}
+
+
+""
+" Add at least one health checker
+" {checker_name} can be specified by either a list of strings or a single string.
+" It does not modify any values if the checker already exists
+function! health#add_checker(checker_name) abort " {{{
+  if type(a:checker_name) == type('')
+    call s:add_single_checker(a:checker_name)
+  elseif type(a:checker_name) == type([])
+    for checker in a:checker_name
+      call s:add_single_checker(checker)
     endfor
   endif
-
-  if !empty(python_bin)
-    let [pyversion, current, latest, status] = s:version_info(python_bin)
-    if a:version != str2nr(pyversion)
-      call add(notes, 'Warning: Got an unexpected version of Python.  '
-            \ . 'This could lead to confusing error messages.  Please '
-            \ . 'consider this before reporting bugs to plugin developers.')
-    endif
-    if a:version == 3 && str2float(pyversion) < 3.3
-      call add(notes, 'Warning: Python 3.3+ is recommended.')
-    endif
-
-    echo '  Python Version:' pyversion
-    echo printf('  %s-neovim Version: %s', python_bin_name, current)
-
-    if current == 'not found'
-      call add(notes, 'Error: Neovim Python client is not installed.')
-    endif
-
-    if latest == 'unknown'
-      call add(notes, 'Warning: Unable to fetch latest Neovim Python client version.')
-    endif
-
-    if status == 'outdated'
-      echon ' (latest: '.latest.')'
-    else
-      echon ' ('.status.')'
-    endif
+endfunction " }}}
+
+""
+" Enable at least one health checker
+" {checker_name} can be specified by either a list of strings or a single string.
+function! health#enable_checker(checker_name) abort " {{{
+  if type(a:checker_name) == type('')
+    call s:enable_single_checker(a:checker_name)
+  elseif type(a:checker_name) == type([])
+    for checker in a:checker_name
+      call s:enable_single_checker(checker)
+    endfor
   endif
-
-  call s:echo_notes(notes)
-endfunction
-
-
-function! s:diagnose_ruby() abort
-  echo 'Checking: Ruby'
-  let ruby_vers = systemlist('ruby -v')[0]
-  let ruby_prog = provider#ruby#Detect()
-  let notes = []
-
-  if empty(ruby_prog)
-    let ruby_prog = 'not found'
-    let prog_vers = 'not found'
-    call add(notes, 'Suggestion: Install the neovim RubyGem using ' .
-          \ '`gem install neovim`.')
-  else
-    silent let prog_vers = systemlist(ruby_prog . ' --version')[0]
-
-    if v:shell_error
-      let prog_vers = 'outdated'
-      call add(notes, 'Suggestion: Install the latest neovim RubyGem using ' .
-            \ '`gem install neovim`.')
-    elseif s:version_cmp(prog_vers, "0.2.0") == -1
-      let prog_vers .= ' (outdated)'
-      call add(notes, 'Suggestion: Install the latest neovim RubyGem using ' .
-            \ '`gem install neovim`.')
-    endif
+endfunction " }}}
+
+""
+" Disable at least one health checker
+" {checker_name} can be specified by either a list of strings or a single string.
+function! health#disable_checker(checker_name) abort " {{{
+  if type(a:checker_name) == type('')
+    call s:disable_single_checker(a:checker_name)
+  elseif type(a:checker_name) == type([])
+    for checker in a:checker_name
+      call s:disable_single_checker(checker)
+    endfor
   endif
+endfunction " }}}
 
-  echo '  Ruby Version: ' . ruby_vers
-  echo '  Host Executable: ' . ruby_prog
-  echo '  Host Version: ' . prog_vers
-
-  call s:echo_notes(notes)
-endfunction
+function! s:change_file_name_to_health_checker(name) abort " {{{
+  return substitute(substitute(substitute(a:name, ".*autoload/", "", ""), "\\.vim", "#check", ""), "/", "#", "g")
+endfunction " }}}
 
+function! s:_default_checkers() abort " {{{
+  " Get all of the files that are in autoload/health/ folders with a vim
+  " suffix
+  let checker_files = globpath(&runtimepath, 'autoload/health/*.vim', 1, 1)
+  let temp = checker_files[0]
 
-function! health#check(bang) abort
-  redir => report
-  try
-    silent call s:diagnose_python(2)
-    silent echo ''
-    silent call s:diagnose_python(3)
-    silent echo ''
-    silent call s:diagnose_ruby()
-    silent echo ''
-    silent call s:diagnose_manifest()
-    silent echo ''
-  finally
-    redir END
-  endtry
-
-  if a:bang
-    new
-    setlocal bufhidden=wipe
-    call setline(1, split(report, "\n"))
-    setlocal nomodified
-  else
-    echo report
-    echo "\nTip: Use "
-    echohl Identifier
-    echon ":CheckHealth!"
-    echohl None
-    echon " to open this in a new buffer."
-  endif
-endfunction
+  let checkers_to_source = []
+  for file_name in checker_files
+    call add(checkers_to_source, s:change_file_name_to_health_checker(file_name))
+  endfor
+  return checkers_to_source
+endfunction " }}}
+" }}}
diff --git a/runtime/autoload/health/nvim.vim b/runtime/autoload/health/nvim.vim
new file mode 100644
index 0000000000..e6092f1a86
--- /dev/null
+++ b/runtime/autoload/health/nvim.vim
@@ -0,0 +1,426 @@
+" Script variables
+let s:bad_responses = [
+            \ 'unable to parse python response',
+            \ 'unable to parse',
+            \ 'unable to get pypi response',
+            \ 'unable to get neovim executable',
+            \ 'unable to find neovim version'
+            \ ]
+
+""
+" Check if the string is a bad response
+function! s:is_bad_response(s) abort
+    return index(s:bad_responses, a:s) >= 0
+endfunction
+
+function! s:trim(s) abort
+  return substitute(a:s, '^\_s*\|\_s*$', '', 'g')
+endfunction
+
+" Simple version comparison.
+function! s:version_cmp(a, b) abort
+  let a = split(a:a, '\.')
+  let b = split(a:b, '\.')
+
+  for i in range(len(a))
+    if a[i] > b[i]
+      return 1
+    elseif a[i] < b[i]
+      return -1
+    endif
+  endfor
+
+  return 0
+endfunction
+
+
+" Fetch the contents of a URL.
+function! s:download(url) abort
+  let content = ''
+  if executable('curl')
+    let content = system(['curl', '-sL', "'", a:url, "'"])
+  endif
+
+  if empty(content) && executable('python')
+    let script = "
+          \try:\n
+          \    from urllib.request import urlopen\n
+          \except ImportError:\n
+          \    from urllib2 import urlopen\n
+          \\n
+          \try:\n
+          \    response = urlopen('".a:url."')\n
+          \    print(response.read().decode('utf8'))\n
+          \except Exception:\n
+          \    pass\n
+          \"
+    let content = system(['python', '-c', "'", script, "'", '2>/dev/null'])
+  endif
+
+  return content
+endfunction
+
+
+" Get the latest Neovim Python client version from PyPI.  The result is
+" cached.
+function! s:latest_pypi_version() abort
+  if exists('s:pypi_version')
+    return s:pypi_version
+  endif
+
+  let s:pypi_version = 'unable to get pypi response'
+  let pypi_info = s:download('https://pypi.python.org/pypi/neovim/json')
+  if !empty(pypi_info)
+    let pypi_data = json_decode(pypi_info)
+    let s:pypi_version = get(get(pypi_data, 'info', {}), 'version', 'unable to parse')
+    return s:pypi_version
+  endif
+endfunction
+
+
+""
+" Get version information using the specified interpreter.  The interpreter is
+" used directly in case breaking changes were introduced since the last time
+" Neovim's Python client was updated.
+"
+" Returns [
+"           python executable version,
+"           current nvim version,
+"           current pypi nvim status,
+"           installed version status
+"         ]
+function! s:version_info(python) abort
+  let pypi_version = s:latest_pypi_version()
+  let python_version = s:trim(system([
+        \ a:python,
+        \ '-c',
+        \ 'import sys; print(".".join(str(x) for x in sys.version_info[:3]))',
+        \ ]))
+
+  if empty(python_version)
+    let python_version = 'unable to parse python response'
+  endif
+
+  let nvim_path = s:trim(system([
+        \ a:python,
+        \ '-c',
+        \ 'import neovim; print(neovim.__file__)',
+        \ '2>/dev/null']))
+
+  let nvim_path = s:trim(system([
+        \ 'python3',
+        \ '-c',
+        \ 'import neovim; print(neovim.__file__)'
+        \ ]))
+        " \ '2>/dev/null']))
+
+  if empty(nvim_path)
+    return [python_version, 'unable to find neovim executable', pypi_version, 'unable to get neovim executable']
+  endif
+
+  let nvim_version = 'unable to find neovim version'
+  let base = fnamemodify(nvim_path, ':h')		
+  for meta in glob(base.'-*/METADATA', 1, 1) + glob(base.'-*/PKG-INFO', 1, 1)		
+    for meta_line in readfile(meta)		
+      if meta_line =~# '^Version:'		
+        let nvim_version = matchstr(meta_line, '^Version: \zs\S\+')		
+      endif		
+    endfor		
+  endfor
+
+  let version_status = 'unknown'
+  if !s:is_bad_response(nvim_version) && !s:is_bad_response(pypi_version)
+    if s:version_cmp(nvim_version, pypi_version) == -1
+      let version_status = 'outdated'
+    else
+      let version_status = 'up to date'
+    endif
+  endif
+
+  return [python_version, nvim_version, pypi_version, version_status]
+endfunction
+
+
+" Check the Python interpreter's usability.
+function! s:check_bin(bin) abort
+  if !filereadable(a:bin)
+    call health#report_error(printf('"%s" was not found.', a:bin))
+    return 0
+  elseif executable(a:bin) != 1
+    call health#report_error(printf('"%s" is not executable.', a:bin))
+    return 0
+  endif
+  return 1
+endfunction
+
+
+
+
+" Load the remote plugin manifest file and check for unregistered plugins
+function! s:check_manifest() abort
+  call health#report_start('Remote Plugins')
+  let existing_rplugins = {}
+
+  for item in remote#host#PluginsForHost('python')
+    let existing_rplugins[item.path] = 'python'
+  endfor
+
+  for item in remote#host#PluginsForHost('python3')
+    let existing_rplugins[item.path] = 'python3'
+  endfor
+
+  let require_update = 0
+
+  for path in map(split(&runtimepath, ','), 'resolve(v:val)')
+    let python_glob = glob(path.'/rplugin/python*', 1, 1)
+    if empty(python_glob)
+      continue
+    endif
+
+    let python_dir = python_glob[0]
+    let python_version = fnamemodify(python_dir, ':t')
+
+    for script in glob(python_dir.'/*.py', 1, 1)
+          \ + glob(python_dir.'/*/__init__.py', 1, 1)
+      let contents = join(readfile(script))
+      if contents =~# '\<\%(from\|import\)\s\+neovim\>'
+        if script =~# '/__init__\.py$'
+          let script = fnamemodify(script, ':h')
+        endif
+
+        if !has_key(existing_rplugins, script)
+          let msg = printf('"%s" is not registered.', fnamemodify(path, ':t'))
+          if python_version ==# 'pythonx'
+            if !has('python2') && !has('python3')
+              let msg .= ' (python2 and python3 not available)'
+            endif
+          elseif !has(python_version)
+            let msg .= printf(' (%s not available)', python_version)
+          else
+            let require_update = 1
+          endif
+
+          call health#report_warn(msg)
+        endif
+
+        break
+      endif
+    endfor
+  endfor
+
+  if require_update
+    call health#report_warn('Out of date', ['Run `:UpdateRemotePlugins`'])
+  else
+    call health#report_ok('Up to date')
+  endif
+endfunction
+
+
+function! s:check_python(version) abort
+  let python_bin_name = 'python'.(a:version == 2 ? '2' : '3')
+  let pyenv = resolve(exepath('pyenv'))
+  let pyenv_root = exists('$PYENV_ROOT') ? resolve($PYENV_ROOT) : 'n'
+  let venv = exists('$VIRTUAL_ENV') ? resolve($VIRTUAL_ENV) : ''
+  let host_prog_var = python_bin_name.'_host_prog'
+  let host_skip_var = python_bin_name.'_host_skip_check'
+  let python_bin = ''
+  let python_multiple = []
+
+  call health#report_start('Python ' . a:version . ' Configuration')
+
+  if exists('g:'.host_prog_var)
+    call health#report_info(printf('Using: g:%s = "%s"', host_prog_var, get(g:, host_prog_var)))
+  endif
+
+  let [python_bin_name, pythonx_errs] = provider#pythonx#Detect(a:version)
+  if empty(python_bin_name)
+    call health#report_warn('No Python interpreter was found with the neovim '
+            \ . 'module.  Using the first available for diagnostics.')
+
+    " TODO: Not sure what to do about these errors, or if this is the right
+    " type.
+    if !empty(pythonx_errs)
+      call health#report_warn(pythonx_errs)
+    endif
+    let old_skip = get(g:, host_skip_var, 0)
+    let g:[host_skip_var] = 1
+    let [python_bin_name, pythonx_errs] = provider#pythonx#Detect(a:version)
+    let g:[host_skip_var] = old_skip
+  endif
+
+  if !empty(python_bin_name)
+    if exists('g:'.host_prog_var)
+      let python_bin = exepath(python_bin_name)
+    endif
+    let python_bin_name = fnamemodify(python_bin_name, ':t')
+  endif
+
+  if !empty(pythonx_errs)
+    call health#report_error('Provier python has reported errors:', pythonx_errs)
+  endif
+
+  if !empty(python_bin_name) && empty(python_bin) && empty(pythonx_errs)
+    if !exists('g:'.host_prog_var)
+      call health#report_warn(printf('"g:%s" is not set.  Searching for '
+            \ . '%s in the environment.', host_prog_var, python_bin_name))
+    endif
+
+    if !empty(pyenv)
+      if empty(pyenv_root)
+        call health#report_warn(
+              \ 'pyenv was found, but $PYENV_ROOT is not set.',
+              \ ['Did you follow the final install instructions?']
+              \ )
+      else
+        call health#report_ok(printf('pyenv found: "%s"', pyenv))
+      endif
+
+      let python_bin = s:trim(system(
+            \ printf('"%s" which %s 2>/dev/null', pyenv, python_bin_name)))
+
+      if empty(python_bin)
+        call health#report_warn(printf('pyenv couldn''t find %s.', python_bin_name))
+      endif
+    endif
+
+    if empty(python_bin)
+      let python_bin = exepath(python_bin_name)
+
+      if exists('$PATH')
+        for path in split($PATH, ':')
+          let path_bin = path.'/'.python_bin_name
+          if path_bin != python_bin && index(python_multiple, path_bin) == -1
+                \ && executable(path_bin)
+            call add(python_multiple, path_bin)
+          endif
+        endfor
+
+        if len(python_multiple)
+          " This is worth noting since the user may install something
+          " that changes $PATH, like homebrew.
+          call health#report_info(printf('There are multiple %s executables found.  '
+                \ . 'Set "g:%s" to avoid surprises.', python_bin_name, host_prog_var))
+        endif
+
+        if python_bin =~# '\<shims\>'
+          call health#report_warn(printf('"%s" appears to be a pyenv shim.', python_bin), [
+                      \ 'The "pyenv" executable is not in $PATH,',
+                      \ 'Your pyenv installation is broken. You should set '
+                      \ . '"g:'.host_prog_var.'" to avoid surprises.',
+                      \ ])
+        endif
+      endif
+    endif
+  endif
+
+  if !empty(python_bin)
+    if empty(venv) && !empty(pyenv) && !exists('g:'.host_prog_var)
+          \ && !empty(pyenv_root) && resolve(python_bin) !~# '^'.pyenv_root.'/'
+      call health#report_warn('pyenv is not set up optimally.', [
+            \ printf('Suggestion: Create a virtualenv specifically '
+            \ . 'for Neovim using pyenv and use "g:%s".  This will avoid '
+            \ . 'the need to install Neovim''s Python client in each '
+            \ . 'version/virtualenv.', host_prog_var)
+            \ ])
+    elseif !empty(venv) && exists('g:'.host_prog_var)
+      if !empty(pyenv_root)
+        let venv_root = pyenv_root
+      else
+        let venv_root = fnamemodify(venv, ':h')
+      endif
+
+      if resolve(python_bin) !~# '^'.venv_root.'/'
+        call health#report_warn('Your virtualenv is not set up optimally.', [
+              \ printf('Suggestion: Create a virtualenv specifically '
+              \ . 'for Neovim and use "g:%s".  This will avoid '
+              \ . 'the need to install Neovim''s Python client in each '
+              \ . 'virtualenv.', host_prog_var)
+              \ ])
+      endif
+    endif
+  endif
+
+  if empty(python_bin) && !empty(python_bin_name)
+    " An error message should have already printed.
+    call health#report_error(printf('"%s" was not found.', python_bin_name))
+  elseif !empty(python_bin) && !s:check_bin(python_bin)
+    let python_bin = ''
+  endif
+
+  " Check if $VIRTUAL_ENV is active
+  let virtualenv_inactive = 0
+
+  if exists('$VIRTUAL_ENV')
+    if !empty(pyenv)
+      let pyenv_prefix = resolve(s:trim(system([pyenv, 'prefix'])))
+      if $VIRTUAL_ENV != pyenv_prefix
+        let virtualenv_inactive = 1
+      endif
+    elseif !empty(python_bin_name) && exepath(python_bin_name) !~# '^'.$VIRTUAL_ENV.'/'
+      let virtualenv_inactive = 1
+    endif
+  endif
+
+  if virtualenv_inactive
+    let suggestions = [
+          \ 'If you are using Zsh, see: http://vi.stackexchange.com/a/7654/5229',
+          \ ]
+    call health#report_warn(
+          \ '$VIRTUAL_ENV exists but appears to be inactive. '
+          \ . 'This could lead to unexpected results.',
+          \ suggestions)
+  endif
+
+  " Diagnostic output
+  call health#report_info('Executable:' . (empty(python_bin) ? 'Not found' : python_bin))
+  if len(python_multiple)
+    for path_bin in python_multiple
+      call health#report_info('Other python executable: ' . path_bin)
+    endfor
+  endif
+
+  if !empty(python_bin)
+    let [pyversion, current, latest, status] = s:version_info(python_bin)
+    if a:version != str2nr(pyversion)
+      call health#report_warn('Got an unexpected version of Python.' .
+                  \ ' This could lead to confusing error messages.')
+    endif
+    if a:version == 3 && str2float(pyversion) < 3.3
+      call health#report_warn('Python 3.3+ is recommended.')
+    endif
+
+    call health#report_info('Python Version: ' . pyversion)
+    call health#report_info(printf('%s-neovim Version: %s', python_bin_name, current))
+
+    if s:is_bad_response(current)
+      let suggestions = [
+            \ 'Error found was: ' . current,
+            \ 'Use the command `$ pip' . a:version . ' install neovim`',
+            \ ]
+      call health#report_error(
+            \ 'Neovim Python client is not installed.',
+            \ suggestions)
+    endif
+
+    if s:is_bad_response(latest)
+      call health#report_warn('Unable to fetch latest Neovim Python client version.')
+    endif
+
+    if s:is_bad_response(status)
+      call health#report_warn('Latest Neovim Python client versions: ('.latest.')')
+    else
+      call health#report_ok('Latest Neovim Python client is installed: ('.status.')')
+    endif
+  endif
+
+endfunction
+
+
+function! health#nvim#check() abort
+  silent call s:check_python(2)
+  silent echo ''
+  silent call s:check_python(3)
+  silent echo ''
+  silent call s:check_manifest()
+  silent echo ''
+endfunction
diff --git a/runtime/doc/pi_health.txt b/runtime/doc/pi_health.txt
new file mode 100644
index 0000000000..d61c42bc06
--- /dev/null
+++ b/runtime/doc/pi_health.txt
@@ -0,0 +1,146 @@
+*pi_health.txt*   Check the status of your Neovim system
+
+Author: TJ DeVries <devries.timothyj@gmail.com>
+
+==============================================================================
+1. Contents					 *health.vim-contents*
+
+	1. Contents				: |health.vim-contents|
+	2. Health.vim introduction		: |health.vim-intro|
+	3. Health.vim manual			: |health.vim-manual|
+		3.1 Health.vim commands		: |health.vim-commands|
+	4. Making a new checker			: |health.vim-checkers|
+
+==============================================================================
+2. Health.vim introduction			*health.vim-intro*
+
+Debugging common issues is a time consuming task that many developers would
+like to eliminate, and where elimination is impossible, minimize. Many common
+questions and difficulties could be answered by a simple check of an
+environment variable or a setting that the user has made. However, even with
+FAQs and other manuals, it can be difficult to suggest the path a user should
+take without knowing some information about their system.
+
+Health.vim aims to solve this problem in two ways for both core and plugin
+maintainers.
+
+The way this is done is to provide an interface that users will know to check
+first before posting question in the issue tracker, dev channels, etc.  This
+is similar to how |:help| functions currently. The user experiencing
+difficulty can run |:CheckHealth| to view the status of one's system.
+
+The aim of |:CheckHealth| is two-fold.
+
+The first aim is to provide maintainers with an overview of the user's working
+environment. This skips large amounts of time where the maintainer must
+instruct the user on which steps to take to get debug information, and allows
+the maintainer to extend existing health scripts as more helpful debug
+information is found.
+
+The second aim is to provide maintainers a way of automating the answering of
+frequently encountered question. A common occurrence with Neovim is that the
+user has not installed the necessary Python modules to interact with Python
+remote plugins. A simple check of whether the Neovim remote plugin is
+installed can lead to a suggestion of >
+
+	You have not installed the Neovim Python module
+	You might want to try `$ pip install Neovim`
+
+< 
+With these possibilities, it allows the maintainer of a plugin to spend more
+time on active development, rather than trying to spend time on debugging
+common issues many times.
+
+==============================================================================
+3. Health.vim manual					*health.vim-manual*
+
+3.1 Commands
+------------
+
+:CheckHealth[!]						*:CheckHealth*
+	Run all health checkers found in g:health_checkers
+
+	It will check your setup for common problems that may be keeping a
+	plugin from functioning correctly.  Include the output of this command
+	in bug reports to help reduce the amount of time it takes to address
+	your issue.  With "!" the output will be placed in a new buffer which
+	can make it easier to save to a file or copy to the clipboard.
+
+
+3.2 Functions						*health.functions*
+-------------
+
+3.2.1 Report Functions					*health.report_functions*
+----------------------
+
+The |health.report_functions| are used by the plugin maintainer to remove the
+hassle of formatting multiple different levels of output. Not only does it
+remove the hassle of formatting, but it also provides users with a consistent
+interface for viewing the health information about the system.
+
+These functions are also expected to have the capability to produce output in
+multiple different formats. For example, if parsing of the results were to be
+done by a remote plugin, the results could be output in a valid JSON format
+and then the remote plugin could parse the results easily.
+
+health#report_start({name})				*health.funcs.report_start*
+	Start a report section.  It should represent a general area of tests
+	that can be understood from the argument {name} To start a new report
+	section, use this function again
+
+health#report_info({msg})				*health.funcs.report_info*
+	Use {msg} to report information in the current section
+
+health#report_ok({msg})					*health.funcs.report_ok*
+	Use {msg} to represent the check that has passed
+
+health#report_warn({msg}, ...)				*health.funcs.report_warn*
+	Use {msg} to represent a failed health check and optionally a list of
+	suggestions on how to fix it.
+
+health#report_error({msg}, ...)				*health.funcs.report_error*
+	Use {msg} to represent a critically failed health check and optionally
+	a list of suggestions on how to fix it.
+
+3.3 User Functions					*health.user_functions*
+------------------
+
+health#{my_plug}#check()				*health.user_checker*
+	A user defined function to run all of the checks that are required for
+	either debugging or suggestion making. An example might be something
+	like: >
+
+	function! health#my_plug#check() abort
+		silent call s:check_environment_vars()
+		silent call s:check_python_configuration()
+	endfunction
+<
+	This function will be found, sourced, and automatically called when
+	the user invokes |:CheckHealth|.
+
+	All output will be captured from the health checker. It is recommended
+	that the plugin maintainer uses the calls described in
+	|health.report_functions|. The benefits these functions provide are
+	described in the same section.
+
+
+==============================================================================
+4. Making a new checker				*health.vim-checkers*
+
+Health checkers are the scripts that check the health of the system. Neovim
+has built in checkers, which can be found in `runtime/autoload/health/`. To
+add a checker for a plugin, add a `health` folder in the `autoload` directory
+of your plugin. It is then suggested that the name of your script be
+`{plug_name}.vim`. For example, the health checker for `my_plug` might be
+placed in: >
+
+	$PLUGIN_BASE/autoload/health/my_plug.vim
+>
+
+Inside this script, a function must be specified to run. This function is
+described in |health.user_checker|.
+
+
+==============================================================================
+
+vim:tw=78:ts=8:ft=help:fdm=marker
diff --git a/runtime/doc/provider.txt b/runtime/doc/provider.txt
index 7380fb9346..63dbb00896 100644
--- a/runtime/doc/provider.txt
+++ b/runtime/doc/provider.txt
@@ -79,14 +79,6 @@ TROUBLESHOOTING					*python-trouble*
 If you have trouble with a plugin that uses the `neovim` Python client, use
 the |:CheckHealth| command to diagnose your setup.
 
-								 *:CheckHealth*
-:CheckHealth[!]	  Check your setup for common problems that may be keeping a
-		  plugin from functioning correctly.  Include the output of
-		  this command in bug reports to help reduce the amount of
-		  time it takes to address your issue.  With "!" the output
-		  will be placed in a new buffer which can make it easier to
-		  save to a file or copy to the clipboard.
-
 ==============================================================================
 Ruby integration		    	      *provider-ruby*
 
diff --git a/runtime/plugin/health.vim b/runtime/plugin/health.vim
index db094a03a4..04345781a6 100644
--- a/runtime/plugin/health.vim
+++ b/runtime/plugin/health.vim
@@ -1 +1,3 @@
+
+" call health#add_checker('health#nvim#check')
 command! -bang CheckHealth call health#check(<bang>0)
diff --git a/runtime/syntax/health.vim b/runtime/syntax/health.vim
new file mode 100644
index 0000000000..1e8e522b4d
--- /dev/null
+++ b/runtime/syntax/health.vim
@@ -0,0 +1,20 @@
+if exists("b:current_syntax")
+    finish
+endif
+
+syntax keyword healthError ERROR
+highlight link healthError Error
+
+syntax keyword healthWarning WARNING
+highlight link healthWarning Todo
+
+syntax keyword healthInfo INFO
+highlight link healthInfo Identifier
+
+syntax keyword healthSuccess SUCCESS
+highlight link healthSuccess Function
+
+syntax keyword healthSuggestion SUGGESTION
+highlight link healthSuggestion String
+
+let b:current_syntax = "health"
diff --git a/test/functional/plugin/health_spec.lua b/test/functional/plugin/health_spec.lua
new file mode 100644
index 0000000000..972cabd662
--- /dev/null
+++ b/test/functional/plugin/health_spec.lua
@@ -0,0 +1,58 @@
+local helpers = require('test.functional.helpers')(after_each)
+local plugin_helpers = require('test.functional.plugin.helpers')
+
+describe('health.vim', function()
+  before_each(function()
+    plugin_helpers.reset()
+  end)
+
+  it('should echo the results when using the basic functions', function()
+    helpers.execute("call health#report_start('Foo')")
+    local report = helpers.redir_exec([[call health#report_start('Check Bar')]])
+      .. helpers.redir_exec([[call health#report_ok('Bar status')]])
+      .. helpers.redir_exec([[call health#report_ok('Other Bar status')]])
+      .. helpers.redir_exec([[call health#report_warn('Zub')]])
+      .. helpers.redir_exec([[call health#report_start('Baz')]])
+      .. helpers.redir_exec([[call health#report_warn('Zim', ['suggestion 1', 'suggestion 2'])]])
+
+    local expected_contents = {
+      'Checking: Check Bar',
+      'SUCCESS: Bar status',
+      'WARNING: Zub',
+      'SUGGESTIONS:',
+      '- suggestion 1',
+      '- suggestion 2'
+    }
+
+    for _, content in ipairs(expected_contents) do
+      assert(string.find(report, content))
+    end
+  end)
+
+
+  describe('CheckHealth', function()
+    -- Run the health check and store important results
+    -- Run it here because it may take awhile to complete, depending on the system
+    helpers.execute([[CheckHealth!]])
+    local report = helpers.curbuf_contents()
+    local health_checkers = helpers.redir_exec("echo g:health_checkers")
+
+    it('should find the default checker upon execution', function()
+      assert(string.find(health_checkers, "'health#nvim#check': v:true"))
+    end)
+
+    it('should alert the user that health#nvim#check is running', function()
+      assert(string.find(report, '# Checking health'))
+      assert(string.find(report, 'Checker health#nvim#check says:'))
+      assert(string.find(report, 'Checking:'))
+    end)
+  end)
+
+  it('should allow users to disable checkers', function()
+    helpers.execute("call health#disable_checker('health#nvim#check')")
+    helpers.execute("CheckHealth!")
+    local health_checkers = helpers.redir_exec("echo g:health_checkers")
+
+    assert(string.find(health_checkers, "'health#nvim#check': v:false"))
+  end)
+end)