Merge #4980 'Support legacy `:ruby` commands'.

11 files changed, 412 insertions, 16 deletions

diff --git a/.ci/install.sh b/.ci/install.sh
index cb2362a70e..93c9a930ac 100755
--- a/.ci/install.sh
+++ b/.ci/install.sh
@@ -29,3 +29,6 @@ if [[ "${TRAVIS_OS_NAME}" == osx ]]; then
 else
   CC=cc pip3.3 -q install --user --upgrade neovim
 fi
+
+echo "Install neovim RubyGem."
+gem install --no-document --version ">= 0.2.0" neovim
diff --git a/runtime/autoload/health.vim b/runtime/autoload/health.vim
index dc362577a6..0a698e6492 100644
--- a/runtime/autoload/health.vim
+++ b/runtime/autoload/health.vim
@@ -404,6 +404,39 @@ function! s:diagnose_python(version) abort
 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+      let prog_vers = 'outdated'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+      let prog_vers .= ' (outdated)'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
+  endif
+
+  echo '  Ruby Version: ' . ruby_vers
+  echo '  Host Executable: ' . ruby_prog
+  echo '  Host Version: ' . prog_vers
+
+  call s:echo_notes(notes)
+endfunction
+
+
 function! health#check(bang) abort
   redir => report
   try
@@ -411,6 +444,8 @@ function! health#check(bang) abort
     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
diff --git a/runtime/autoload/provider/ruby.vim b/runtime/autoload/provider/ruby.vim
index aad8c09d28..e9130b98c1 100644
--- a/runtime/autoload/provider/ruby.vim
+++ b/runtime/autoload/provider/ruby.vim
@@ -1,12 +1,18 @@
 " The Ruby provider helper
-if exists('s:loaded_ruby_provider')
+if exists('g:loaded_ruby_provider')
   finish
 endif
+let g:loaded_ruby_provider = 1
 
-let s:loaded_ruby_provider = 1
+function! provider#ruby#Detect() abort
+  return exepath('neovim-ruby-host')
+endfunction
+
+function! provider#ruby#Prog()
+  return s:prog
+endfunction
 
 function! provider#ruby#Require(host) abort
-  " Collect registered Ruby plugins into args
   let args = []
   let ruby_plugins = remote#host#PluginsForHost(a:host.name)
 
@@ -16,19 +22,43 @@ function! provider#ruby#Require(host) abort
 
   try
     let channel_id = rpcstart(provider#ruby#Prog(), args)
-
-    if rpcrequest(channel_id, 'poll') == 'ok'
+    if rpcrequest(channel_id, 'poll') ==# 'ok'
       return channel_id
     endif
   catch
     echomsg v:throwpoint
     echomsg v:exception
   endtry
-
-  throw remote#host#LoadErrorForHost(a:host.orig_name,
-        \ '$NVIM_RUBY_LOG_FILE')
+  throw remote#host#LoadErrorForHost(a:host.orig_name, '$NVIM_RUBY_LOG_FILE')
 endfunction
 
-function! provider#ruby#Prog() abort
-  return 'neovim-ruby-host'
+function! provider#ruby#Call(method, args)
+  if s:err != ''
+    echoerr s:err
+    return
+  endif
+
+  if !exists('s:host')
+    try
+      let s:host = remote#host#Require('legacy-ruby-provider')
+    catch
+      let s:err = v:exception
+      echohl WarningMsg
+      echomsg v:exception
+      echohl None
+      return
+    endtry
+  endif
+  return call('rpcrequest', insert(insert(a:args, 'ruby_'.a:method), s:host))
 endfunction
+
+let s:err = ''
+let s:prog = provider#ruby#Detect()
+let s:plugin_path = expand('<sfile>:p:h') . '/script_host.rb'
+
+if empty(s:prog)
+  let s:err = 'Cannot find the neovim RubyGem. Try :CheckHealth'
+endif
+
+call remote#host#RegisterClone('legacy-ruby-provider', 'ruby')
+call remote#host#RegisterPlugin('legacy-ruby-provider', s:plugin_path, [])
diff --git a/runtime/autoload/provider/script_host.rb b/runtime/autoload/provider/script_host.rb
new file mode 100644
index 0000000000..1dade766c7
--- /dev/null
+++ b/runtime/autoload/provider/script_host.rb
@@ -0,0 +1,8 @@
+begin
+  require "neovim/ruby_provider"
+rescue LoadError
+  warn(
+    "Your neovim RubyGem is missing or out of date. " +
+    "Install the latest version using `gem install neovim`."
+  )
+end
diff --git a/runtime/doc/if_ruby.txt b/runtime/doc/if_ruby.txt
new file mode 100644
index 0000000000..fdd63501ea
--- /dev/null
+++ b/runtime/doc/if_ruby.txt
@@ -0,0 +1,185 @@
+*if_ruby.txt*
+
+
+		  VIM REFERENCE MANUAL    by Shugo Maeda
+
+The Ruby Interface to Vim				*ruby* *Ruby*
+
+
+1. Commands			|ruby-commands|
+2. The VIM module		|ruby-vim|
+3. VIM::Buffer objects		|ruby-buffer|
+4. VIM::Window objects		|ruby-window|
+5. Global variables		|ruby-globals|
+
+			*E266* *E267* *E268* *E269* *E270* *E271* *E272* *E273*
+
+The home page for ruby is http://www.ruby-lang.org/.  You can find links for
+downloading Ruby there.
+
+==============================================================================
+1. Commands						*ruby-commands*
+
+							*:ruby* *:rub*
+:rub[y] {cmd}		Execute Ruby command {cmd}.  A command to try it out: >
+				:ruby print "Hello"
+
+:rub[y] << {endpattern}
+{script}
+{endpattern}
+			Execute Ruby script {script}.
+			{endpattern} must NOT be preceded by any white space.
+			If {endpattern} is omitted, it defaults to a dot '.'
+			like for the |:append| and |:insert| commands.  This
+			form of the |:ruby| command is mainly useful for
+			including ruby code in vim scripts.
+			Note: This command doesn't work when the Ruby feature
+			wasn't compiled in.  To avoid errors, see
+			|script-here|.
+
+Example Vim script: >
+
+	function! RedGem()
+	ruby << EOF
+	class Garnet
+		def initialize(s)
+			@buffer = VIM::Buffer.current
+			vimputs(s)
+		end
+		def vimputs(s)
+			@buffer.append(@buffer.count,s)
+		end
+	end
+	gem = Garnet.new("pretty")
+	EOF
+	endfunction
+<
+
+						*:rubydo* *:rubyd* *E265*
+:[range]rubyd[o] {cmd}	Evaluate Ruby command {cmd} for each line in the
+			[range], with $_ being set to the text of each line in
+			turn, without a trailing <EOL>.  Setting $_ will change
+			the text, but note that it is not possible to add or
+			delete lines using this command.
+			The default for [range] is the whole file: "1,$".
+
+							*:rubyfile* *:rubyf*
+:rubyf[ile] {file}	Execute the Ruby script in {file}.  This is the same as
+			":ruby load 'file'", but allows file name completion.
+
+Executing Ruby commands is not possible in the |sandbox|.
+
+==============================================================================
+2. The VIM module					*ruby-vim*
+
+Ruby code gets all of its access to vim via the "VIM" module.
+
+Overview >
+	print "Hello"			      # displays a message
+	VIM.command(cmd)		      # execute an Ex command
+	num = VIM::Window.count		      # gets the number of windows
+	w = VIM::Window[n]		      # gets window "n"
+	cw = VIM::Window.current	      # gets the current window
+	num = VIM::Buffer.count		      # gets the number of buffers
+	b = VIM::Buffer[n]		      # gets buffer "n"
+	cb = VIM::Buffer.current	      # gets the current buffer
+	w.height = lines		      # sets the window height
+	w.cursor = [row, col]		      # sets the window cursor position
+	pos = w.cursor			      # gets an array [row, col]
+	name = b.name			      # gets the buffer file name
+	line = b[n]			      # gets a line from the buffer
+	num = b.count			      # gets the number of lines
+	b[n] = str			      # sets a line in the buffer
+	b.delete(n)			      # deletes a line
+	b.append(n, str)		      # appends a line after n
+	line = VIM::Buffer.current.line       # gets the current line
+	num = VIM::Buffer.current.line_number # gets the current line number
+	VIM::Buffer.current.line = "test"     # sets the current line number
+<
+
+Module Functions:
+
+							*ruby-message*
+VIM::message({msg})
+	Displays the message {msg}.
+
+							*ruby-set_option*
+VIM::set_option({arg})
+	Sets a vim option.  {arg} can be any argument that the ":set" command
+	accepts.  Note that this means that no spaces are allowed in the
+	argument!  See |:set|.
+
+							*ruby-command*
+VIM::command({cmd})
+	Executes Ex command {cmd}.
+
+							*ruby-evaluate*
+VIM::evaluate({expr})
+	Evaluates {expr} using the vim internal expression evaluator (see
+	|expression|).  Returns the expression result as a string.
+	A |List| is turned into a string by joining the items and inserting
+	line breaks.
+
+==============================================================================
+3. VIM::Buffer objects					*ruby-buffer*
+
+VIM::Buffer objects represent vim buffers.
+
+Class Methods:
+
+current		Returns the current buffer object.
+count		Returns the number of buffers.
+self[{n}]	Returns the buffer object for the number {n}.  The first number
+		is 0.
+
+Methods:
+
+name		Returns the name of the buffer.
+number		Returns the number of the buffer.
+count		Returns the number of lines.
+length		Returns the number of lines.
+self[{n}]	Returns a line from the buffer. {n} is the line number.
+self[{n}] = {str}
+		Sets a line in the buffer. {n} is the line number.
+delete({n})	Deletes a line from the buffer. {n} is the line number.
+append({n}, {str})
+		Appends a line after the line {n}.
+line		Returns the current line of the buffer if the buffer is
+		active.
+line = {str}    Sets the current line of the buffer if the buffer is active.
+line_number     Returns the number of the current line if the buffer is
+		active.
+
+==============================================================================
+4. VIM::Window objects					*ruby-window*
+
+VIM::Window objects represent vim windows.
+
+Class Methods:
+
+current		Returns the current window object.
+count		Returns the number of windows.
+self[{n}]	Returns the window object for the number {n}.  The first number
+		is 0.
+
+Methods:
+
+buffer		Returns the buffer displayed in the window.
+height		Returns the height of the window.
+height = {n}	Sets the window height to {n}.
+width		Returns the width of the window.
+width = {n}	Sets the window width to {n}.
+cursor		Returns a [row, col] array for the cursor position.
+cursor = [{row}, {col}]
+		Sets the cursor position to {row} and {col}.
+
+==============================================================================
+5. Global variables					*ruby-globals*
+
+There are two global variables.
+
+$curwin		The current window object.
+$curbuf		The current buffer object.
+
+==============================================================================
+ vim:tw=78:ts=8:ft=help:norl:
diff --git a/runtime/doc/provider.txt b/runtime/doc/provider.txt
index db5c61879c..7380fb9346 100644
--- a/runtime/doc/provider.txt
+++ b/runtime/doc/provider.txt
@@ -88,6 +88,25 @@ the |:CheckHealth| command to diagnose your setup.
 		  save to a file or copy to the clipboard.
 
 ==============================================================================
+Ruby integration		    	      *provider-ruby*
+
+Nvim supports the Vim legacy |ruby-vim| interface via external Ruby
+interpreters connected via |RPC|.
+
+
+RUBY QUICKSTART ~
+
+To use Vim Ruby plugins with Nvim, just install the latest `neovim` RubyGem: >
+    $ gem install neovim
+
+
+RUBY PROVIDER CONFIGURATION ~
+						*g:loaded_ruby_provider*
+To disable Ruby support: >
+    let g:loaded_ruby_provider = 1
+
+
+==============================================================================
 Clipboard integration 			      *provider-clipboard* *clipboard*
 
 Nvim has no direct connection to the system clipboard. Instead it is
diff --git a/runtime/doc/vim_diff.txt b/runtime/doc/vim_diff.txt
index e536ea873a..a5b1cbf9b1 100644
--- a/runtime/doc/vim_diff.txt
+++ b/runtime/doc/vim_diff.txt
@@ -202,13 +202,12 @@ Additional differences:
 
 ==============================================================================
 5. Missing legacy features				 *nvim-features-missing*
-				     *if_ruby* *if_lua* *if_perl* *if_mzscheme* *if_tcl*
+				     *if_lua* *if_perl* *if_mzscheme* *if_tcl*
 
 These legacy Vim features may be implemented in the future, but they are not
 planned for the current milestone.
 
 - vim.bindeval() (new feature in Vim 7.4 Python interface)
-- |if_ruby|
 - |if_lua|
 - |if_perl|
 - |if_mzscheme|
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 55fa974797..47d44b148a 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -22344,7 +22344,10 @@ bool eval_has_provider(char *name)
     } \
   }
 
-  static int has_clipboard = -1, has_python = -1, has_python3 = -1;
+  static int has_clipboard = -1;
+  static int has_python = -1;
+  static int has_python3 = -1;
+  static int has_ruby = -1;
 
   if (!strcmp(name, "clipboard")) {
     check_provider(clipboard);
@@ -22355,6 +22358,9 @@ bool eval_has_provider(char *name)
   } else if (!strcmp(name, "python")) {
     check_provider(python);
     return has_python;
+  } else if (!strcmp(name, "ruby")) {
+    check_provider(ruby);
+    return has_ruby;
   }
 
   return false;
diff --git a/src/nvim/ex_cmds.lua b/src/nvim/ex_cmds.lua
index 76191d5a56..3f5d9b3244 100644
--- a/src/nvim/ex_cmds.lua
+++ b/src/nvim/ex_cmds.lua
@@ -2170,19 +2170,19 @@ return {
     command='ruby',
     flags=bit.bor(RANGE, EXTRA, NEEDARG, CMDWIN),
     addr_type=ADDR_LINES,
-    func='ex_script_ni',
+    func='ex_ruby',
   },
   {
     command='rubydo',
     flags=bit.bor(RANGE, DFLALL, EXTRA, NEEDARG, CMDWIN),
     addr_type=ADDR_LINES,
-    func='ex_ni',
+    func='ex_rubydo',
   },
   {
     command='rubyfile',
     flags=bit.bor(RANGE, FILE1, NEEDARG, CMDWIN),
     addr_type=ADDR_LINES,
-    func='ex_ni',
+    func='ex_rubyfile',
   },
   {
     command='rviminfo',
diff --git a/src/nvim/ex_cmds2.c b/src/nvim/ex_cmds2.c
index b56b1cf013..6d24ba91f2 100644
--- a/src/nvim/ex_cmds2.c
+++ b/src/nvim/ex_cmds2.c
@@ -897,6 +897,21 @@ void ex_pydo(exarg_T *eap)
   script_host_do_range("python", eap);
 }
 
+void ex_ruby(exarg_T *eap)
+{
+  script_host_execute("ruby", eap);
+}
+
+void ex_rubyfile(exarg_T *eap)
+{
+  script_host_execute_file("ruby", eap);
+}
+
+void ex_rubydo(exarg_T *eap)
+{
+  script_host_do_range("ruby", eap);
+}
+
 void ex_python3(exarg_T *eap)
 {
   script_host_execute("python3", eap);
diff --git a/test/functional/provider/ruby_spec.lua b/test/functional/provider/ruby_spec.lua
new file mode 100644
index 0000000000..7b0e17688d
--- /dev/null
+++ b/test/functional/provider/ruby_spec.lua
@@ -0,0 +1,96 @@
+local helpers = require('test.functional.helpers')(after_each)
+
+local eq = helpers.eq
+local feed = helpers.feed
+local clear = helpers.clear
+local funcs = helpers.funcs
+local meths = helpers.meths
+local insert = helpers.insert
+local expect = helpers.expect
+local command = helpers.command
+local write_file = helpers.write_file
+local curbufmeths = helpers.curbufmeths
+
+do
+  clear()
+  command('let g:prog = provider#ruby#Detect()')
+  local prog = meths.get_var('prog')
+
+  if prog == '' then
+    pending(
+      "Cannot find the neovim RubyGem. Try :CheckHealth",
+      function() end)
+    return
+  end
+end
+
+before_each(function()
+  clear()
+end)
+
+describe('ruby feature test', function()
+  it('works', function()
+    eq(1, funcs.has('ruby'))
+  end)
+end)
+
+describe(':ruby command', function()
+  it('evaluates ruby', function()
+    command('ruby VIM.command("let g:set_by_ruby = [100, 0]")')
+    eq({100, 0}, meths.get_var('set_by_ruby'))
+  end)
+
+  it('supports nesting', function()
+    command([[ruby VIM.command('ruby VIM.command("let set_by_nested_ruby = 555")')]])
+    eq(555, meths.get_var('set_by_nested_ruby'))
+  end)
+end)
+
+describe(':rubyfile command', function()
+  it('evaluates a ruby file', function()
+    local fname = 'rubyfile.rb'
+    write_file(fname, 'VIM.command("let set_by_rubyfile = 123")')
+    command('rubyfile rubyfile.rb')
+    eq(123, meths.get_var('set_by_rubyfile'))
+    os.remove(fname)
+  end)
+end)
+
+describe(':rubydo command', function()
+  it('exposes the $_ variable for modifying lines', function()
+    insert('abc\ndef\nghi\njkl')
+    expect([[
+      abc
+      def
+      ghi
+      jkl]])
+
+    feed('ggjvj:rubydo $_.upcase!<CR>')
+    expect([[
+      abc
+      DEF
+      GHI
+      jkl]])
+  end)
+
+  it('operates on all lines when not given a range', function()
+    insert('abc\ndef\nghi\njkl')
+    expect([[
+      abc
+      def
+      ghi
+      jkl]])
+
+    feed(':rubydo $_.upcase!<CR>')
+    expect([[
+      ABC
+      DEF
+      GHI
+      JKL]])
+  end)
+
+  it('does not modify the buffer if no changes are made', function()
+    command('normal :rubydo 42')
+    eq(false, curbufmeths.get_option('modified'))
+  end)
+end)