using entry-points instead of module and egg paths

notes.md

@@ -36,3 +36,7 @@ can cause eggs to be installed incorrectly (due to a misdetected root path)
 * support buildout extensions?
 * support inheritance
 * make virtualenv relocatable at the end of the build process
+
+## Tests TODO
+
+* test to allow user paths in uranium script.

scripts/uranium

@@ -89,6 +89,9 @@ def _install_virtualenv(install_dir):
 
 
 def _install_uranium(virtualenv_dir, uranium_dir=None, version=None):
+    if uranium_dir:
+        uranium_dir = os.path.expanduser(uranium_dir)
+
     log_file = os.path.join(virtualenv_dir, 'uranium_install_log.txt')
     pip_executable = os.path.join(virtualenv_dir, 'bin', 'pip')
     uranium_name = uranium_dir or 'uranium'

setup.py

@@ -19,7 +19,7 @@
 ]
 
 setup(name='uranium',
-      version='0.0.48',
+      version='0.0.49',
       description='a build system for python',
       long_description='a build system for python',
       author='Yusuke Tsutsumi',
@@ -45,6 +45,9 @@
       entry_points={
           'console_scripts': [
               'uranium=uranium:main'
+          ],
+          'uranium.plugin': [
+              'default = uranium.example_plugin:ExamplePlugin'
           ]
       },
       tests_require=tests_require

uranium/__init__.py

@@ -15,8 +15,9 @@
 """
 __import__('pkg_resources').declare_namespace(__name__)
 import logging
+import pkg_resources
 from contextlib import contextmanager
-from pip._vendor import pkg_resources
+from pip._vendor import pkg_resources as pip_pkg_resources
 from docopt import docopt
 from virtualenv import make_environment_relocatable
 from .uranium import Uranium
@@ -75,28 +76,33 @@ def _activate_virtualenv(uranium_dir):
     # we modify the executable directly, because pip invokes this to install packages.
     sys.executable = os.path.join(uranium_dir, 'bin', 'python')
 
+    for _pkg_resources in [pkg_resources, pip_pkg_resources]:
+        _clean_package_resources(_pkg_resources, old_prefix)
+
+    # in the past, an incorrect real_prefix directory was being
+    # generated when using uranium. it looks like sys.prefix
+    # works as a replacement, so let's use that.
+    sys.real_prefix = sys.prefix
+
+
+def _clean_package_resources(_pkg_resources, old_prefix):
     # this is a workaround for pip. Pip utilizes pkg_resources
     # and the path to determine what's installed in the current
     # sandbox
     #
     # we remove the requirements that are installed
     # from the parent environment, so pip will detect
     # the requirement from the current virtualenv
-    for name, req in list(pkg_resources.working_set.by_key.items()):
+    for name, req in list(_pkg_resources.working_set.by_key.items()):
         if old_prefix in req.location:
-            del pkg_resources.working_set.by_key[name]
+            del _pkg_resources.working_set.by_key[name]
 
     # ensure that pkg_resources only searches the
     # existing sys.path. These variables are set on
     # initialization, so we have to reset them
     # when activating a sandbox.
     pkg_resources.working_set.entries = sys.path
 
-    # in the past, an incorrect real_prefix directory was being
-    # generated when using uranium. it looks like sys.prefix
-    # works as a replacement, so let's use that.
-    sys.real_prefix = sys.prefix
-
 LOGGING_NAMES = [__name__]
 
 

uranium/buildout_adapter.py

@@ -40,7 +40,7 @@ def install_part(part):
             LOGGER.error(str(e))
 
     def _get_recipe_class(self, recipe_name):
-        return self._classloader.get_class(recipe_name)
+        return self._classloader.get_entry_point(recipe_name, "zc.buildout")
 
     def __getitem__(self, key):
         if key == "buildout":

uranium/classloader.py

@@ -1,4 +1,5 @@
 import inspect
+import pkg_resources
 from .compat import import_module
 from .pip_manager import PackageNotFound
 
@@ -19,25 +20,20 @@ class ClassLoader(object):
     def __init__(self, pip_manager):
         self._pip = pip_manager
 
-    def get_class_from_spec(self, class_spec):
-        """
-        resolve a spec string from one of the following options:
-
-        <egg_name>:<module>
-        <module>
-        """
-        egg_name = None
-        module_path = class_spec
-        if ':' in class_spec:
-            egg_name, module_path = class_spec.split(':')
+    def get_entry_point(self, entry_point, group):
+        if ":" in entry_point:
+            dist, name = entry_point.split(":")
+        else:
+            dist, name = entry_point, "default"
 
         try:
-            import_module(module_path)
+            import_module(dist)
         except ImportError:
-            if egg_name:
-                self._install_egg(egg_name)
+            self._install_egg(dist)
 
-        return self.get_class(module_path)
+        return pkg_resources.load_entry_point(
+            dist, group, name
+        )
 
     def get_class(self, class_module_path):
         """

uranium/isotope_runner.py

@@ -24,4 +24,6 @@ def remove_part(isotope):
         pass
 
     def _get_isotope_class(self, isotope_name):
-        return self._classloader.get_class_from_spec(isotope_name)
+        return self._classloader.get_entry_point(
+            isotope_name, "uranium.plugin"
+        )

uranium/tests/test_classloader.py

@@ -9,14 +9,7 @@ class TestClassLoader(object):
     def setUp(self):
         self._classloader = ClassLoader(None)
 
-    def test_find_example_plugin(self):
-        eq_(self._classloader.get_class_from_spec('uranium.example_plugin'),
+    def test_get_entry_point(self):
+        eq_(self._classloader.get_entry_point("uranium",
+                                              "uranium.plugin"),
             ExamplePlugin)
-
-    def test_find_example_plugin_with_eggname(self):
-        self._classloader._install_egg = Mock()
-        eq_(self._classloader.get_class_from_spec('uranium:uranium.example_plugin'),
-            ExamplePlugin)
-        # the behaviour here only downloads an egg if it doesn't already
-        # exist.
-        # self._classloader._install_egg.assert_called_with('uranium')

uranium/tests/test_uranium.py

@@ -14,7 +14,7 @@ def setUp(self):
             },
             'parts': {
                 'platform-versions': {
-                    'isotope': 'uranium.example_plugin',
+                    'isotope': 'uranium',
                     'versions': {
                         'nose': '1.1.0'
                     }