add support for RubyGems

README.rst

@@ -122,6 +122,13 @@ Check `PyPI <https://pypi.python.org/>`_ for updates.
 pypi
   The name used on PyPI, e.g. ``PySide``.
 
+Check RubyGems
+--------------
+Check `RubyGems <https://rubygems.org/>`_ for updates.
+
+gems
+  The name used on RubyGems, e.g. ``sass``.
+
 Check Local Pacman Database
 ---------------------------
 This is used when you run ``nvchecker`` on an Arch Linux system and the program always keeps up with a package in your configured repositories for `Pacman <https://wiki.archlinux.org/index.php/Pacman>`_.

nvchecker/get_version.py

@@ -3,7 +3,7 @@ from importlib import import_module
 
 logger = logging.getLogger(__name__)
 handler_precedence = (
-  'github', 'aur', 'pypi', 'archpkg', 'pacman',
+  'github', 'aur', 'pypi', 'archpkg', 'gems', 'pacman',
   'cmd', 'gcode_hg', 'regex', 'manual',
 )
 

nvchecker/source/gems.py

@@ -0,0 +1,17 @@
+import json
+from functools import partial
+
+from tornado.httpclient import AsyncHTTPClient
+
+GEMS_URL = 'https://rubygems.org/api/v1/versions/%s.json'
+
+def get_version(name, conf, callback):
+  repo = conf.get('gems') or name
+  url = GEMS_URL % repo
+  AsyncHTTPClient().fetch(url, user_agent='lilydjwg/nvchecker',
+                          callback=partial(_gems_done, name, callback))
+
+def _gems_done(name, callback, res):
+  data = json.loads(res.body.decode('utf-8'))
+  version = data[0]['number']
+  callback(name, version)