style: import UserError and use Recipe().install()

- import UserError from zc.buildout for shorter usage
- use Recipe(...).install() one-liner when recipe varible is uncessary

rubygems.py

@@ -8,10 +8,10 @@ import os
 import re
 import stat
 import subprocess
-import zc.buildout
 
 import six.moves.urllib as urllib
 
+from zc.buildout import UserError
 from zc.buildout.easy_install import allow_picked_versions
 from slapos.recipe import rmtree
 from slapos.recipe.downloadunpacked import Recipe as Download
@@ -42,13 +42,12 @@ class Recipe(object):
         if self.gems:
             self.gems = self.gems.split()
         else:
-            raise zc.buildout.UserError(
-                "Configuration error, 'gems' option is missing")
+            raise UserError("Configuration error, 'gems' option is missing")
 
         self.url = options.get('url')
         if(self.url and options.get('version')):
-            raise zc.buildout.UserError(
-                "Configuration error, 'url' and 'version' options are mutually exclusive")
+            raise UserError("Configuration error, "
+                            "'url' and 'version' options are mutually exclusive")
 
         # Allow to define specific ruby executable. If not, take just 'ruby'
         self.ruby_executable = options.get('ruby-executable', 'ruby')
@@ -67,17 +66,14 @@ class Recipe(object):
         try:
             return subprocess.check_output(cmd, env=env, universal_newlines=True)
         except OSError as e:
-            raise zc.buildout.UserError(
-                'System error, command failed: %s: %s' % (e, cmd))
+            raise UserError('System error, command failed: %s: %s' % (e, cmd))
         except subprocess.CalledProcessError as e:
             self.log.error(e.output)
             if e.returncode < 0:
-                raise zc.buildout.UserError(
-                    'System error, command received signal %s: %s'
-                    % (-e.returncode, e.cmd)
-                )
+                raise UserError('System error, command received signal %s: %s'
+                                 % (-e.returncode, e.cmd))
             elif e.returncode > 0:
-                raise zc.buildout.UserError(
+                raise UserError(
                     'System error, command failed with exit code %s: %s' 
                     % (e.returncode, e.cmd)
                 )
@@ -124,11 +120,11 @@ class Recipe(object):
                 % (' '.join(cons_dict.values()), dep_dict['gemname'],  gemname)
             )
 
-        raise zc.buildout.UserError(
+        raise UserError(
             'Configuration error, version %s for gem %s '
             'does not satisfy dependency constraint %s of gem %s' 
             % (dep_dict['version'], dep_dict['gemname'],
-              ' '.join(cons_dict.values()), gemname)
+               ' '.join(cons_dict.values()), gemname)
         )
 
     def _join_paths(self, *paths):
@@ -141,10 +137,8 @@ class Recipe(object):
                 map(strip, line.split('=', 1)) for line in env
             ]])
         except ValueError:  # Unpacking impossible
-            raise zc.buildout.UserError(
-                'Configuration error, '
-                'every environment line should contain a "=" sign'
-            )
+            raise UserError('Configuration error, '
+                            'every environment line should contain a "=" sign')
         return env
 
     def _get_env(self):
@@ -195,7 +189,7 @@ class Recipe(object):
                 f.close()
         if r:
             return url or r.group(0), r.group(1)
-        raise zc.buildout.UserError("Can't find rubygems version.")
+        raise UserError("Can't find rubygems version.")
 
     def _install_rubygems(self, url, version):
         srcdir = os.path.join(self.buildout['buildout']['parts-directory'],
@@ -204,8 +198,7 @@ class Recipe(object):
             'url': url,
             'destination': srcdir,
         }
-        recipe = Download(self.buildout, self.name, options)
-        recipe.install()
+        Download(self.buildout, self.name, options).install()
 
         current_dir = os.getcwd()
         os.chdir(srcdir)
@@ -313,7 +306,7 @@ class Recipe(object):
 
             url, version = self._get_rubygems_url_and_version()
             if int(version.split(".")[0]) < 2:
-                raise zc.buildout.UserError("Rubygems version must be >= 2.0.0")
+                raise UserError("Rubygems version must be >= 2.0.0")
 
             self._install_rubygems(url, version)
             gem_executable = glob.glob(os.path.join(bindir, 'gem*'))[0]
@@ -322,7 +315,7 @@ class Recipe(object):
             for gem_dict in gem_dict_list:
                 if self.deployment:
                     if 'version' not in gem_dict:
-                        raise zc.buildout.UserError(
+                        raise UserError(
                             'Configuration error, '
                             'version for gem %s is missing' % gem_dict['gemname']
                         )
@@ -333,7 +326,7 @@ class Recipe(object):
                         match = [gem_d for gem_d in gem_dict_list
                                   if dep_dict['gemname'] == gem_d['gemname']]
                         if not match:
-                            raise zc.buildout.UserError(
+                            raise UserError(
                                 'Configuration error, '
                                 'version for dependency %s is missing'
                                 % dep_dict['gemname']

tests/test_rubygems.py

@@ -13,7 +13,7 @@ import re
 
 from six import BytesIO
 
-import zc.buildout
+from zc.buildout import UserError
 
 import rubygems
 
@@ -135,8 +135,7 @@ class RubyGemsTestCase(unittest.TestCase):
 class RubyGemsDefaultTestCase(RubyGemsTestCase):
     @fixture({'recipe': {'gems': 'sass'}})
     def test_success(self, path, patches, buildout, name, options, version):
-        recipe = rubygems.Recipe(buildout, name, options)
-        recipe.install()
+        rubygems.Recipe(buildout, name, options).install()
 
         expected_install_arg_list_list = [
             [
@@ -151,7 +150,7 @@ class RubyGemsDefaultTestCase(RubyGemsTestCase):
     @fixture({'recipe': {}})
     def test_missing_gems(self, path, patches, buildout, name, options, version):
         self.assertRaisesRegexp(
-            zc.buildout.UserError,
+            UserError,
             "Configuration error, 'gems' option is missing",
             rubygems.Recipe, buildout, name, options
         )
@@ -159,48 +158,43 @@ class RubyGemsDefaultTestCase(RubyGemsTestCase):
     @fixture({'recipe': {'gems': 'sass'}})
     def test_oserror(self, path, patches, buildout, name, options, version):
         patches['check_output'].side_effect = OSError
-        recipe = rubygems.Recipe(buildout, name, options)
         self.assertRaisesRegexp(
-            zc.buildout.UserError,
+            UserError,
             'System error, command failed: .*',
-            recipe.install
+            rubygems.Recipe(buildout, name, options).install,
         )
 
     @fixture({'recipe': {'gems': 'sass'}})
     def test_signal_received(self, path, patches, buildout, name, options, version):
         exception = subprocess.CalledProcessError(-1, '')
         patches['check_output'].side_effect = exception
-        recipe = rubygems.Recipe(buildout, name, options)
         self.assertRaisesRegexp(
-            zc.buildout.UserError,
+            UserError,
             'System error, command received signal 1: .*',
-            recipe.install
+            rubygems.Recipe(buildout, name, options).install,
         )
 
     @fixture({'recipe': {'gems': 'sass'}})
     def test_non_zero_exitcode(self, path, patches, buildout, name, options, version):
         exception = subprocess.CalledProcessError(1, '')
         patches['check_output'].side_effect = exception
-        recipe = rubygems.Recipe(buildout, name, options)
         self.assertRaisesRegexp(
-            zc.buildout.UserError,
+            UserError,
             'System error, command failed with exit code 1: .*',
-            recipe.install
+            rubygems.Recipe(buildout, name, options).install,
         )
 
     @fixture({'recipe': {'gems': 'sass'}})
     def test_update(self, path, patches, buildout, name, options, version):
-        recipe = rubygems.Recipe(buildout, name, options)
-        recipe.update()
+        rubygems.Recipe(buildout, name, options).update()
 
     @fixture({'recipe': {'gems': 'sass', 'environment': 'invalid'}})
     def test_invalid_environment(self, path, patches, buildout, name, options, version):
-        recipe = rubygems.Recipe(buildout, name, options)
         self.assertRaisesRegexp(
-          zc.buildout.UserError,
-          'Configuration error, '
-          'every environment line should contain a "=" sign',
-          recipe.install
+            UserError,
+            'Configuration error, '
+            'every environment line should contain a "=" sign',
+            rubygems.Recipe(buildout, name, options).install,
         )
 
     @fixture({'recipe': {
@@ -209,21 +203,19 @@ class RubyGemsDefaultTestCase(RubyGemsTestCase):
                 % RUBYGEMS_DEFAULT_VERSION,
     }})
     def test_version_from_url(self, path, patches, buildout, name, options, version):
-        recipe = rubygems.Recipe(buildout, name, options)
-        recipe.install()
+        rubygems.Recipe(buildout, name, options).install()
 
     @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()
+        rubygems.Recipe(buildout, name, options).install()
 
     @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,
+        self.assertRaisesRegexp(
+            UserError,
             "Can't find rubygems version.",
-            recipe.install
+            rubygems.Recipe(buildout, name, options).install,
         )
 
     @fixture({'recipe': {'gems': 'sass'}})
@@ -234,9 +226,8 @@ class RubyGemsDefaultTestCase(RubyGemsTestCase):
 
     @fixture({'recipe': {'gems': 'sass==1.0'}})
     def test_pinned_versions(self, path, patches, buildout, name, options, version):
-        recipe = rubygems.Recipe(buildout, name, options)
         touch(path / 'rubygems/bin/gem')
-        recipe.install()
+        rubygems.Recipe(buildout, name, options).install()
 
         args = patches['check_output'].mock_calls[1][1]
         for arg in args[0]:
@@ -256,8 +247,7 @@ class RubyGemsDefaultTestCase(RubyGemsTestCase):
             rubygems_setup_output = fd.read()
         patches['check_output'].return_value = rubygems_setup_output
 
-        recipe = rubygems.Recipe(buildout, name, options)
-        recipe.install()
+        rubygems.Recipe(buildout, name, options).install()
 
     @fixture({'recipe': {
         'gems': 'sass',
@@ -267,7 +257,7 @@ class RubyGemsDefaultTestCase(RubyGemsTestCase):
     }})
     def test_version_and_url(self, path, patches, buildout, name, options, version):
         self.assertRaisesRegexp(
-            zc.buildout.UserError,
+            UserError,
             "Configuration error, 'url' and 'version' options are mutually exclusive",
             rubygems.Recipe, buildout, name, options
         )
@@ -334,32 +324,29 @@ class RubyGemsDeploymentTestCase(RubyGemsTestCase):
     @deployment_fixture({'recipe': {'gems': 'sass'}})
     def test_deployment_not_pinned_version_error(
             self, path, patches, buildout, name, options, version):
-        recipe = rubygems.Recipe(buildout, name, options)
         self.assertRaisesRegexp(
-            zc.buildout.UserError,
+            UserError,
             'Configuration error, version for gem sass is missing',
-            recipe.install
+            rubygems.Recipe(buildout, name, options).install,
         )
 
     @deployment_fixture({'recipe': {'gems': 'rash==0.1.0'}})
     def test_deployment_not_pinned_dependency_error(
             self, path, patches, buildout, name, options, version):
-        recipe = rubygems.Recipe(buildout, name, options)
         self.assertRaisesRegexp(
-            zc.buildout.UserError,
+            UserError,
             'Configuration error, version for dependency hashie is missing',
-            recipe.install
+            rubygems.Recipe(buildout, name, options).install,
         )
 
     @deployment_fixture({'recipe': {'gems': 'rash==0.1.0 hashie==0.3.0'}})
     def test_deployment_more_or_equal_constraint_error(
             self, path, patches, buildout, name, options, version):
-        recipe = rubygems.Recipe(buildout, name, options)
         self.assertRaisesRegexp(
-            zc.buildout.UserError,
+            UserError,
             'Configuration error, version 0.3.0 for gem hashie '
             'does not satisfy dependency constraint >= 0.3.1 of gem rash',
-            recipe.install
+            rubygems.Recipe(buildout, name, options).install,
         )
 
     @deployment_fixture({'recipe': {'gems': 'rash==0.1.0 hashie==0.3.1'}})
@@ -371,12 +358,11 @@ class RubyGemsDeploymentTestCase(RubyGemsTestCase):
     @deployment_fixture({'recipe': {'gems': 'rash==0.3.0 hashie==1.1.0'}})
     def test_deployment_similar_constraint_error(
             self, path, patches, buildout, name, options, version):
-        recipe = rubygems.Recipe(buildout, name, options)
         self.assertRaisesRegexp(
-            zc.buildout.UserError,
+            UserError,
             'Configuration error, version 1.1.0 for gem hashie '
             'does not satisfy dependency constraint < 1.1 of gem rash',
-            recipe.install
+            rubygems.Recipe(buildout, name, options).install,
         )
 
     @deployment_fixture({'recipe': {'gems': 'rash==0.3.0 hashie==1.0.0'}})
@@ -393,13 +379,12 @@ class RubyGemsDeploymentTestCase(RubyGemsTestCase):
     }})
     def test_deployment_more_or_equal_constraint_error(
             self, path, patches, buildout, name, options, version):
-        recipe = rubygems.Recipe(buildout, name, options)
         self.assertRaisesRegexp(
-            zc.buildout.UserError,
+            UserError,
             'Configuration error, version 9.0.2 for gem cucumber-messages '
             'does not satisfy dependency constraint >= 9.0.3 '
             'of gem cucumber-gherkin',
-            recipe.install
+            rubygems.Recipe(buildout, name, options).install,
         )
 
     @deployment_fixture({'recipe': {
@@ -416,12 +401,11 @@ class RubyGemsDeploymentTestCase(RubyGemsTestCase):
     @deployment_fixture({'recipe': {'gems': 'hoe==3.4.0 rake==11.0.0'}})
     def test_deployment_less_constraint_error(
             self, path, patches, buildout, name, options, version):
-        recipe = rubygems.Recipe(buildout, name, options)
         self.assertRaisesRegexp(
-            zc.buildout.UserError,
+            UserError,
             'Configuration error, version 11.0.0 for gem rake '
             'does not satisfy dependency constraint < 11.0 of gem hoe',
-            recipe.install
+            rubygems.Recipe(buildout, name, options).install,
         )
 
     @deployment_fixture({'recipe': {'gems': 'hoe==3.4.0 rake==10.0.1'}})
@@ -436,12 +420,11 @@ class RubyGemsDeploymentTestCase(RubyGemsTestCase):
     }})
     def test_deployment_not_pinned_subdependency_error(
             self, path, patches, buildout, name, options, version):
-        recipe = rubygems.Recipe(buildout, name, options)
         self.assertRaisesRegexp(
-            zc.buildout.UserError,
+            UserError,
             'Configuration error, version for dependency '
             'cucumber-messages is missing',
-            recipe.install
+            rubygems.Recipe(buildout, name, options).install,
         )
 
     @deployment_fixture({'recipe': {
@@ -463,13 +446,12 @@ class RubyGemsDeploymentTestCase(RubyGemsTestCase):
     }})
     def test_deployment_subdependency_constraint_error(
             self, path, patches, buildout, name, options, version):
-        recipe = rubygems.Recipe(buildout, name, options)
         self.assertRaisesRegexp(
-            zc.buildout.UserError,
+            UserError,
             'Configuration error, version 12.2.0 for gem cucumber-messages '
             'does not satisfy dependency constraint >= 12.3 '
             'of gem cucumber-gherkin',
-            recipe.install
+            rubygems.Recipe(buildout, name, options).install,
         )
 
     @deployment_fixture({'recipe': {
@@ -493,12 +475,11 @@ class RubyGemsDeploymentTestCase(RubyGemsTestCase):
     }})
     def test_deployment_similar_second_constraint_error(
             self, path, patches, buildout, name, options, version):
-        recipe = rubygems.Recipe(buildout, name, options)
         self.assertRaisesRegexp(
-            zc.buildout.UserError,
+            UserError,
             'Configuration error, version 15.0.0 for gem cucumber-gherkin '
             'does not satisfy dependency constraint < 15 of gem cucumber-core',
-            recipe.install
+            rubygems.Recipe(buildout, name, options).install,
         )
 
     @deployment_fixture({'recipe': {
@@ -517,12 +498,11 @@ class RubyGemsDeploymentTestCase(RubyGemsTestCase):
     }})
     def test_deployment_version_exclusion_constraint_error(
             self, path, patches, buildout, name, options, version):
-        recipe = rubygems.Recipe(buildout, name, options)
         self.assertRaisesRegexp(
-            zc.buildout.UserError,
+            UserError,
             'Configuration error, version 1.0.0 for gem hashie '
             'does not satisfy dependency constraint != 1.0.0 of gem sass',
-            recipe.install
+            rubygems.Recipe(buildout, name, options).install,
         )
 
     @deployment_fixture({'recipe': {