Fix undefined rubygems version

Traceback (most recent call last):
  ...
    recipe.install()
  File "rubygemsrecipe/rubygems.py", line 347, in install
    gem_executable):
  File "rubygemsrecipe/rubygems.py", line 300, in get_dependency_list
    if self.version[0] < '3':
TypeError: 'NoneType' object has no attribute '__getitem__'

The test that was added in 60b10788 is adapted due to the call to subprocess.checkout .

rubygems.py

@@ -34,6 +34,7 @@ class Recipe(object):
             buildout['buildout']['parts-directory'],
             self.name,
         )
+        self.bindir = os.path.join(self.options['location'], 'bin')
 
         self.gems = options.get('gems')
         if self.gems:
@@ -42,10 +43,12 @@ class Recipe(object):
             raise zc.buildout.UserError(
                 "Configuration error, 'gems' option is missing")
 
-        self.version = options.get('version')
         self.url = options.get('url')
         # Allow to define specific ruby executable. If not, take just 'ruby'
         self.ruby_executable = options.get('ruby-executable', 'ruby')
+        self.version = self.get_rubygems_version()
+        if int(self.version.split(".")[0]) < 2:
+            raise zc.buildout.UserError("Rubygems version must be >= 2.0.0")
 
         deployment = options.get('deployment')
         self.deployment = is_true(deployment) if deployment else not allow_picked_versions()
@@ -172,45 +175,29 @@ class Recipe(object):
             gem_dict['version'] = parsed_gem[1].strip()
         return gem_dict
 
-    def _get_latest_rubygems(self):
-        if self.url:
-            version = self.version
-            if not version:
-                version = (
-                    re.search(r'rubygems-([0-9.]+).zip$', self.url).group(1)
-                )
-            return (self.url, version)
-
-        if self.version:
-            return ('https://rubygems.org/rubygems/'
-                    'rubygems-%s.zip' % self.version, self.version)
+    def _get_rubygems_url(self, version):
+        if version:
+            return 'https://rubygems.org/rubygems/rubygems-%s.zip' % version
 
         f = urllib.request.urlopen('https://rubygems.org/pages/download')
         s = f.read().decode('utf-8')
         f.close()
-        r = re.search(r'https://rubygems.org/rubygems/'
-                      r'rubygems-([0-9.]+).zip', s)
+        r = re.search(r'https://rubygems.org/rubygems/rubygems-([0-9.]+).zip', s)
         if r:
-            url = r.group(0)
-            version = r.group(1)
-            return (url, version)
+            return r.group(0)
         else:
             raise zc.buildout.UserError(
                 'Can\'t find latest rubygems version.')
 
     def _install_rubygems(self):
-        url, version = self._get_latest_rubygems()
-        if int(version.split(".")[0]) < 2:
-            raise zc.buildout.UserError("Rubygems version must be >= 2.0.0")
         srcdir = os.path.join(self.buildout['buildout']['parts-directory'],
-                              'rubygems-' + version)
+                              'rubygems-' + self.version)
         options = {
-            'url': url,
+            'url': self.url,
             'destination': srcdir,
         }
         recipe = Download(self.buildout, self.name, options)
         recipe.install()
-        self.version = version
 
         current_dir = os.getcwd()
         try:
@@ -324,15 +311,22 @@ class Recipe(object):
             ],
         } for match in self.gem_regex.findall(cmd_result)]
 
+    def get_rubygems_version(self):
+      gem_executable = self.get_gem_executable(self.bindir)
+      if gem_executable:
+          return self.run([gem_executable, '--version',])
+
+      if not self.url:
+          self.url = self._get_rubygems_url(self.options.get('version'))
+      return re.search(r'rubygems-([0-9.]+).zip$', self.url).group(1)
+
     def install(self):
         parts = [self.options['location']]
 
-        bindir = os.path.join(self.options['location'], 'bin')
-        gem_executable = self.get_gem_executable(bindir)
-
+        gem_executable = self.get_gem_executable(self.bindir)
         if not gem_executable:
             self._install_rubygems()
-            gem_executable = self.get_gem_executable(bindir)
+            gem_executable = self.get_gem_executable(self.bindir)
 
         gem_dict_list = list(map(self.get_gem_dict, self.gems))
         for gem_dict in gem_dict_list:
@@ -359,11 +353,11 @@ class Recipe(object):
                             constraint, match[0], gem_dict['gemname'])
 
             self.log.info('installing ruby gem "%s"', gem_dict['gemname'])
-            self._install_gem(gem_dict, gem_executable, bindir) 
+            self._install_gem(gem_dict, gem_executable, self.bindir) 
 
-        for executable in os.listdir(bindir):
+        for executable in os.listdir(self.bindir):
             installed_path = self._install_executable(
-                os.path.join(bindir, executable)
+                os.path.join(self.bindir, executable)
             )
             parts.append(installed_path)
 

tests/test_rubygems.py

@@ -17,6 +17,8 @@ import zc.buildout
 
 import rubygems
 
+RUBYGEMS_DEFAULT_VERSION = '2.0.0'
+
 
 def touch(path):
     with path.open('w') as f:
@@ -24,9 +26,31 @@ def touch(path):
 
 
 class fixture(object):
-    def __init__(self, options=None, version='2.0.0'):
+    def __init__(self, options=None, version=RUBYGEMS_DEFAULT_VERSION,
+                 rubygems_installed=False):
         self.options = options or {}
-        self.version = version
+        self.version = self.options.get('return', {}).get('version', version)
+  
+        self.to_patch = (
+            ('check_output', 'rubygems.subprocess.check_output'),
+            ('urlopen', 'rubygems.urllib.request.urlopen'),
+            ('download', 'rubygems.Download'),
+        )
+  
+        self.patch_return_value_dict = {
+            'urlopen': BytesIO(bytes(
+                          ('https://rubygems.org/rubygems/rubygems-%s.zip'
+                            % RUBYGEMS_DEFAULT_VERSION).encode('utf-8')
+                       )),
+        }
+
+        self.to_create = ()
+  
+        if rubygems_installed:
+            self.to_patch.append(
+                ('get_version', 'rubygems.Recipe.get_rubygems_version'))
+            self.patch_return_value_dict['get_version'] = self.version
+            self.to_create.append(path / 'rubygems/bin/gem')
 
     def __call__(self, func):
         @functools.wraps(func)
@@ -53,24 +77,21 @@ class fixture(object):
 
     def set_up(self):
         name = 'rubygems'
-        version = self.options.get('return', {}).get('version', self.version)
  
-        self.patch((
-            ('check_output', 'rubygems.subprocess.check_output'),
-            ('urlopen', 'rubygems.urllib.request.urlopen'),
-            ('download', 'rubygems.Download'),
-        ))
-        self.patches['urlopen'].return_value = BytesIO(
-            b'https://rubygems.org/rubygems/rubygems-2.0.0.zip'
-        )
+        self.patch(self.to_patch)
+        for k, v in self.patch_return_value_dict.items():
+            self.patches[k].return_value = v
 
         self.makedirs((
             'bin',
-            'ruby-' + version,
-            'rubygems-' + version,
+            'ruby-' + self.version,
+            'rubygems-' + self.version,
             'rubygems/bin',
         ))
 
+        for file_path in self.to_create:
+            touch(file_path)
+
         buildout = {'buildout': dict({
             'parts-directory': str(self.tempdir),
             'bin-directory': str(self.tempdir / 'bin'),
@@ -78,7 +99,7 @@ class fixture(object):
 
         options = self.options.get('recipe', {})
 
-        return buildout, name, options, version
+        return buildout, name, options, self.version
 
     def tear_down(self):
         for patcher in self.patchers.values():
@@ -108,8 +129,9 @@ class RubyGemsTestCase(unittest.TestCase):
 
         args = patches['download'].mock_calls[0][1]
         self.assertEqual(args[2], {
-            'url': 'https://rubygems.org/rubygems/rubygems-2.0.0.zip',
-            'destination': str(path / 'rubygems-2.0.0'),
+            'url': 'https://rubygems.org/rubygems/rubygems-%s.zip'
+                    % RUBYGEMS_DEFAULT_VERSION,
+            'destination': str(path / ('rubygems-' + RUBYGEMS_DEFAULT_VERSION)),
         })
 
         expected_install_arg_list_list.insert(0, [
@@ -193,13 +215,14 @@ class RubyGemsDefaultTestCase(RubyGemsTestCase):
 
     @fixture({'recipe': {
         'gems': 'sass',
-        'url': 'https://rubygems.org/rubygems/rubygems-2.0.0.zip',
+        'url': 'https://rubygems.org/rubygems/rubygems-%s.zip'
+                % RUBYGEMS_DEFAULT_VERSION,
     }})
     def test_version_from_url(self, path, patches, buildout, name, options, version):
         recipe = rubygems.Recipe(buildout, name, options)
         recipe.install()
 
-    @fixture({'recipe': {'gems': 'sass'}, 'version': '2.0.0'})
+    @fixture({'recipe': {'gems': 'sass'}, 'version': RUBYGEMS_DEFAULT_VERSION})
     def test_version(self, path, patches, buildout, name, options, version):
         recipe = rubygems.Recipe(buildout, name, options)
         recipe.install()
@@ -207,10 +230,10 @@ class RubyGemsDefaultTestCase(RubyGemsTestCase):
     @fixture({'recipe': {'gems': 'sass'}})
     def test_no_version(self, path, patches, buildout, name, options, version):
         patches['urlopen'].return_value = BytesIO(b'')
-        recipe = rubygems.Recipe(buildout, name, options)
         self.assertRaisesRegexp(zc.buildout.UserError,
             'Can\'t find latest rubygems version.',
-            recipe.install
+            rubygems.Recipe,
+            buildout, name, options
         )
 
     @fixture({'recipe': {'gems': 'sass'}})
@@ -230,10 +253,9 @@ class RubyGemsDefaultTestCase(RubyGemsTestCase):
         touch(pathlib.Path(recipe.options['location']) / 'bin/sass')
         recipe.install()
 
-    @fixture({'recipe': {'gems': 'sass==1.0'}})
+    @fixture({'recipe': {'gems': 'sass==1.0'}, 'rubygems_installed': True})
     def test_pinned_versions(self, path, patches, buildout, name, options, version):
         recipe = rubygems.Recipe(buildout, name, options)
-        touch(path / 'rubygems/bin/gem')
         recipe.install()
 
         args = patches['check_output'].mock_calls[0][1]
@@ -302,10 +324,12 @@ class RubyGemsDeploymentTestCase(RubyGemsTestCase):
         self.install_with_default_rubygems_test(
             path, patches, expected_install_arg_list_list)
 
-    @deployment_fixture({'recipe': {'gems': 'hashie==0.3.1'}})
+    @deployment_fixture({
+        'recipe': {'gems': 'hashie==0.3.1'},
+        'rubygems_installed': True
+    })
     def test_already_installed_rubygems(
             self, path, patches, buildout, name, options, version):
-        touch(path / 'rubygems/bin/gem')
         self.deployment_install_test(
             buildout, name, path, patches, options, version)