Test site_libs.

pex/pex.py

@@ -96,12 +96,16 @@ def _extras_paths(cls):
       yield os.path.join(standard_lib, path)
 
   @classmethod
-  def _site_libs(cls):
+  def _get_site_packages(cls):
     try:
       from site import getsitepackages
-      site_libs = set(getsitepackages())
+      return set(getsitepackages())
     except ImportError:
-      site_libs = set()
+      return set()
+
+  @classmethod
+  def site_libs(cls):
+    site_libs = cls._get_site_packages()
     site_libs.update([sysconfig.get_python_lib(plat_specific=False),
                       sysconfig.get_python_lib(plat_specific=True)])
     # On windows getsitepackages() returns the python stdlib too.
@@ -193,7 +197,7 @@ def minimum_sys(cls):
     :returns: (sys.path, sys.path_importer_cache, sys.modules) tuple of a
       bare python installation.
     """
-    site_libs = set(cls._site_libs())
+    site_libs = set(cls.site_libs())
     for site_lib in site_libs:
       TRACER.log('Found site-library: %s' % site_lib)
     for extras_path in cls._extras_paths():

tests/test_pex.py

@@ -2,17 +2,24 @@
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
 import os
+import sys
 import textwrap
 from types import ModuleType
 
 import pytest
+from twitter.common.contextutil import temporary_dir
 
-from pex.compatibility import to_bytes
+from pex.compatibility import nested, to_bytes
 from pex.installer import EggInstaller, WheelInstaller
 from pex.pex import PEX
 from pex.testing import make_installer, run_simple_pex_test
 from pex.util import DistributionHelper
 
+try:
+  from unittest import mock
+except ImportError:
+  import mock
+
 
 @pytest.mark.skipif('sys.version_info > (3,)')
 def test_pex_uncaught_exceptions():
@@ -120,6 +127,43 @@ def test_minimum_sys_modules():
   assert tainted_module.__path__ == ['good_path']
 
 
+def test_site_libs():
+  with nested(mock.patch.object(PEX, '_get_site_packages'), temporary_dir()) as (
+          mock_site_packages, tempdir):
+    site_packages = os.path.join(tempdir, 'site-packages')
+    os.mkdir(site_packages)
+    mock_site_packages.return_value = set([site_packages])
+    site_libs = PEX.site_libs()
+    assert site_packages in site_libs
+
+
+def test_site_libs_symlink():
+  with nested(mock.patch.object(PEX, '_get_site_packages'), temporary_dir()) as (
+          mock_site_packages, tempdir):
+    site_packages = os.path.join(tempdir, 'site-packages')
+    os.mkdir(site_packages)
+    site_packages_link = os.path.join(tempdir, 'site-packages-link')
+    os.symlink(site_packages, site_packages_link)
+    mock_site_packages.return_value = set([site_packages_link])
+
+    site_libs = PEX.site_libs()
+    assert os.path.realpath(site_packages) in site_libs
+    assert site_packages_link in site_libs
+
+
+def test_site_libs_excludes_prefix():
+  """Windows returns sys.prefix as part of getsitepackages(). Make sure to exclude it."""
+
+  with nested(mock.patch.object(PEX, '_get_site_packages'), temporary_dir()) as (
+          mock_site_packages, tempdir):
+    site_packages = os.path.join(tempdir, 'site-packages')
+    os.mkdir(site_packages)
+    mock_site_packages.return_value = set([site_packages, sys.prefix])
+    site_libs = PEX.site_libs()
+    assert site_packages in site_libs
+    assert sys.prefix not in site_libs
+
+
 @pytest.mark.parametrize('zip_safe', (False, True))
 @pytest.mark.parametrize('project_name', ('my_project', 'my-project'))
 @pytest.mark.parametrize('installer_impl', (EggInstaller, WheelInstaller))