Running unsaved JavaScript though Node.js with TextMate 2 Notes: It's basically 2 files, one created with the bundle editor (See the tmCommand), and the actual node runner. This also requires an environment variable to be setup pointing to the node command line utility: TM_NODE=/usr/local/bin/node for node installed via homebrew

node_mate.rb

require "#{ENV["TM_SUPPORT_PATH"]}/lib/scriptmate"

class NodeScript < UserScript
  def lang; "JavaScript" end
  def default_extension; ".js" end
  def args
    []
  end
  def executable; @hashbang || ENV['TM_NODE'] || 'node' end
  def version_string
    path = ENV['PATH'].split(':').find { |e| File.exists? File.join(e, executable) }
    node_path = File.join(path.to_s, executable)
    res = %x{ #{executable} -v }.split[0..2].join %{ }
    res + " (#{node_path})"
  end
end

class NodeMate < ScriptMate
  def filter_stderr(str)
    # strings from stderr are passed through this method before printing
    super(str).
    gsub(/(#\d+ )((.+?)\((\d+)\)): /) {
      $1 + '<a href="txmt://open?' + (ENV.has_key?('TM_FILEPATH') ? "url=file://#{$3}&amp;" : '') + 'line=' + $4 + '"> ' + $2 + '</a>: '
    }.
    gsub(/in (.+?) on line (\d+)(<br>$)?/) {
      'in <a href="txmt://open?' + (ENV.has_key?('TM_FILEPATH') ? "url=file://#{$1}&amp;" : '') + 'line=' + $2 + '"> ' + $1 + ' on line ' + $2 + '</a>' + $3.to_s
    }
  end

  def filter_stdout(str)
    # strings from stderr are passed through this method before printing
    super(str).gsub(/\[([^\]]+?) line (\d+)\]<br>$/) {
      '[<a href="txmt://open?' + (ENV.has_key?('TM_FILEPATH') ? "url=file://#{$1}&amp;" : '') + 'line=' + $2 + '">' + $1 + ' line ' + $2 + '</a>]<br>'
    }
  end
end

script = NodeScript.new(STDIN.read)
NodeMate.new(script).emit_html

runJsInNode.tmCommand

<!--
The script is really just this (much like the PHP runner), but the 

#!/bin/sh
/usr/bin/env ruby -- "$TM_BUNDLE_SUPPORT/lib/node_mate.rb"
-->

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>beforeRunningCommand</key>
	<string>nop</string>
	<key>command</key>
	<string>#!/bin/sh
/usr/bin/env ruby -- "$TM_BUNDLE_SUPPORT/lib/node_mate.rb"
</string>
	<key>input</key>
	<string>selection</string>
	<key>inputFormat</key>
	<string>text</string>
	<key>keyEquivalent</key>
	<string>@R</string>
	<key>name</key>
	<string>Run In Node.js</string>
	<key>outputCaret</key>
	<string>afterOutput</string>
	<key>outputFormat</key>
	<string>html</string>
	<key>outputLocation</key>
	<string>newWindow</string>
	<key>scope</key>
	<string>source.js</string>
	<key>uuid</key>
	<string>1DBDEAB4-E18D-4FAD-AC13-318ABEACA3B3</string>
	<key>version</key>
	<integer>2</integer>
</dict>
</plist>