Extract namespace support functionality into a separate module.

setuptools/tests/namespaces.py

+from __future__ import absolute_import, unicode_literals
+
+import textwrap
+
+
+def build_namespace_package(tmpdir, name):
+    src_dir = tmpdir / name
+    src_dir.mkdir()
+    setup_py = src_dir / 'setup.py'
+    namespace, sep, rest = name.partition('.')
+    script = textwrap.dedent("""
+        import setuptools
+        setuptools.setup(
+            name={name!r},
+            version="1.0",
+            namespace_packages=[{namespace!r}],
+            packages=[{namespace!r}],
+        )
+        """).format(**locals())
+    setup_py.write_text(script, encoding='utf-8')
+    ns_pkg_dir = src_dir / namespace
+    ns_pkg_dir.mkdir()
+    pkg_init = ns_pkg_dir / '__init__.py'
+    tmpl = '__import__("pkg_resources").declare_namespace({namespace!r})'
+    decl = tmpl.format(**locals())
+    pkg_init.write_text(decl, encoding='utf-8')
+    pkg_mod = ns_pkg_dir / (rest + '.py')
+    some_functionality = 'name = {rest!r}'.format(**locals())
+    pkg_mod.write_text(some_functionality, encoding='utf-8')
+    return src_dir
+
+
+def make_site_dir(target):
+    """
+    Add a sitecustomize.py module in target to cause
+    target to be added to site dirs such that .pth files
+    are processed there.
+    """
+    sc = target / 'sitecustomize.py'
+    target_str = str(target)
+    tmpl = '__import__("site").addsitedir({target_str!r})'
+    sc.write_text(tmpl.format(**locals()), encoding='utf-8')

setuptools/tests/test_namespaces.py

 from __future__ import absolute_import, unicode_literals
 
 import os
-import textwrap
 import sys
 import subprocess
 
 import pytest
 
+from . import namespaces
 
-class TestNamespaces:
-    @staticmethod
-    def build_namespace_package(tmpdir, name):
-        src_dir = tmpdir / name
-        src_dir.mkdir()
-        setup_py = src_dir / 'setup.py'
-        namespace, sep, rest = name.partition('.')
-        script = textwrap.dedent("""
-            import setuptools
-            setuptools.setup(
-                name={name!r},
-                version="1.0",
-                namespace_packages=[{namespace!r}],
-                packages=[{namespace!r}],
-            )
-            """).format(**locals())
-        setup_py.write_text(script, encoding='utf-8')
-        ns_pkg_dir = src_dir / namespace
-        ns_pkg_dir.mkdir()
-        pkg_init = ns_pkg_dir / '__init__.py'
-        tmpl = '__import__("pkg_resources").declare_namespace({namespace!r})'
-        decl = tmpl.format(**locals())
-        pkg_init.write_text(decl, encoding='utf-8')
-        pkg_mod = ns_pkg_dir / (rest + '.py')
-        some_functionality = 'name = {rest!r}'.format(**locals())
-        pkg_mod.write_text(some_functionality, encoding='utf-8')
-        return src_dir
 
-    @staticmethod
-    def make_site_dir(target):
-        """
-        Add a sitecustomize.py module in target to cause
-        target to be added to site dirs such that .pth files
-        are processed there.
-        """
-        sc = target / 'sitecustomize.py'
-        target_str = str(target)
-        tmpl = '__import__("site").addsitedir({target_str!r})'
-        sc.write_text(tmpl.format(**locals()), encoding='utf-8')
+class TestNamespaces:
 
     @pytest.mark.xfail(sys.version_info < (3, 3),
         reason="Requires PEP 420")
@@ -57,8 +20,8 @@ class TestNamespaces:
         should leave the namespace in tact and both packages reachable by
         import.
         """
-        pkg_A = self.build_namespace_package(tmpdir, 'myns.pkgA')
-        pkg_B = self.build_namespace_package(tmpdir, 'myns.pkgB')
+        pkg_A = namespaces.build_namespace_package(tmpdir, 'myns.pkgA')
+        pkg_B = namespaces.build_namespace_package(tmpdir, 'myns.pkgB')
         site_packages = tmpdir / 'site-packages'
         path_packages = tmpdir / 'path-packages'
         targets = site_packages, path_packages
@@ -71,7 +34,7 @@ class TestNamespaces:
             '-t', str(site_packages),
         ]
         subprocess.check_call(install_cmd)
-        self.make_site_dir(site_packages)
+        namespaces.make_site_dir(site_packages)
         install_cmd = [
             'pip',
             'install',