In test command, add installed eggs to PYTHONPATH when invoking tests so that subprocesses will also have the dependencies available. Fixes #794.

Author: jaraco

CHANGES.rst

@@ -2,6 +2,13 @@
 CHANGES
 =======
 
+v27.3.0
+-------
+
+* #794: In test command, add installed eggs to PYTHONPATH
+  when invoking tests so that subprocesses will also have the
+  dependencies available.
+
 v27.2.0
 -------
 

setuptools/command/test.py

@@ -1,10 +1,12 @@
+import os
+import operator
 import sys
 import contextlib
 from distutils.errors import DistutilsOptionError
 from unittest import TestLoader
 
 from setuptools.extern import six
-from setuptools.extern.six.moves import map
+from setuptools.extern.six.moves import map, filter
 
 from pkg_resources import (resource_listdir, resource_exists, normalize_path,
                            working_set, _namespace_packages,
@@ -112,7 +114,7 @@ def with_project_on_sys_path(self, func):
             func()
 
     @contextlib.contextmanager
-    def project_on_sys_path(self):
+    def project_on_sys_path(self, include_dists=[]):
         with_2to3 = six.PY3 and getattr(self.distribution, 'use_2to3', False)
 
         if with_2to3:
@@ -144,32 +146,69 @@ def project_on_sys_path(self):
         old_modules = sys.modules.copy()
 
         try:
-            sys.path.insert(0, normalize_path(ei_cmd.egg_base))
+            project_path = normalize_path(ei_cmd.egg_base)
+            sys.path.insert(0, project_path)
             working_set.__init__()
             add_activation_listener(lambda dist: dist.activate())
             require('%s==%s' % (ei_cmd.egg_name, ei_cmd.egg_version))
-            yield
+            with self.paths_on_pythonpath([project_path]):
+                yield
         finally:
             sys.path[:] = old_path
             sys.modules.clear()
             sys.modules.update(old_modules)
             working_set.__init__()
 
+    @staticmethod
+    @contextlib.contextmanager
+    def paths_on_pythonpath(paths):
+        """
+        Add the indicated paths to the head of the PYTHONPATH environment
+        variable so that subprocesses will also see the packages at
+        these paths.
+
+        Do this in a context that restores the value on exit.
+        """
+        nothing = object()
+        orig_pythonpath = os.environ.get('PYTHONPATH', nothing)
+        current_pythonpath = os.environ.get('PYTHONPATH', '')
+        try:
+            prefix = os.pathsep.join(paths)
+            to_join = filter(None, [prefix, current_pythonpath])
+            new_path = os.pathsep.join(to_join)
+            if new_path:
+                os.environ['PYTHONPATH'] = new_path
+            yield
+        finally:
+            if orig_pythonpath is nothing:
+                os.environ.pop('PYTHONPATH', None)
+            else:
+                os.environ['PYTHONPATH'] = orig_pythonpath
+
     def run(self):
+        installed_dists = []
         if self.distribution.install_requires:
-            self.distribution.fetch_build_eggs(
-                self.distribution.install_requires)
+            installed_dists.extend(
+                self.distribution.fetch_build_eggs(
+                    self.distribution.install_requires,
+                ))
         if self.distribution.tests_require:
-            self.distribution.fetch_build_eggs(self.distribution.tests_require)
+            installed_dists.extend(
+                    self.distribution.fetch_build_eggs(
+                            self.distribution.tests_require,
+                ))
 
         cmd = ' '.join(self._argv)
         if self.dry_run:
             self.announce('skipping "%s" (dry run)' % cmd)
             return
 
         self.announce('running "%s"' % cmd)
-        with self.project_on_sys_path():
-            self.run_tests()
+
+        paths = map(operator.attrgetter('location'), installed_dists)
+        with self.paths_on_pythonpath(paths):
+            with self.project_on_sys_path():
+                self.run_tests()
 
     def run_tests(self):
         # Purge modules under test from sys.modules. The test loader will

setuptools/dist.py

@@ -362,6 +362,7 @@ def fetch_build_eggs(self, requires):
         )
         for dist in resolved_dists:
             pkg_resources.working_set.add(dist, replace=True)
+        return resolved_dists
 
     def finalize_options(self):
         _Distribution.finalize_options(self)