Extract fixture for the environment.

setuptools/tests/test_egg_info.py

 import os
 import stat
 
+import pytest
+
 from . import environment
 from .textwrap import DALS
 from . import contexts
@@ -29,53 +31,61 @@ class TestEggInfo:
                     print('hello')
                 """))
 
-    def test_egg_base_installed_egg_info(self, tmpdir_cwd):
-        self._create_project()
-        with contexts.tempdir(prefix='setuptools-test.') as temp_dir:
-            os.chmod(temp_dir, stat.S_IRWXU)
+    @pytest.yield_fixture
+    def env(self):
+        class Environment(str): pass
+
+        with contexts.tempdir(prefix='setuptools-test.') as env_dir:
+            env = Environment(env_dir)
+            os.chmod(env_dir, stat.S_IRWXU)
             subs = 'home', 'lib', 'scripts', 'data', 'egg-base'
-            paths = dict(
-                (dirname, os.path.join(temp_dir, dirname))
+            env.paths = dict(
+                (dirname, os.path.join(env_dir, dirname))
                 for dirname in subs
             )
-            list(map(os.mkdir, paths.values()))
-            config = os.path.join(paths['home'], '.pydistutils.cfg')
+            list(map(os.mkdir, env.paths.values()))
+            config = os.path.join(env.paths['home'], '.pydistutils.cfg')
             with open(config, 'w') as f:
                 f.write(DALS("""
                     [egg_info]
                     egg-base = %(egg-base)s
-                    """ % paths
+                    """ % env.paths
                 ))
-            environ = os.environ.copy().update(
-                HOME=paths['home'],
-            )
-            cmd = [
-                'install',
-                '--home', paths['home'],
-                '--install-lib', paths['lib'],
-                '--install-scripts', paths['scripts'],
-                '--install-data', paths['data'],
-            ]
-            code, data = environment.run_setup_py(
-                cmd=cmd,
-                pypath=os.pathsep.join([paths['lib'], str(tmpdir_cwd)]),
-                data_stream=1,
-                env=environ,
-            )
-            if code:
-                raise AssertionError(data)
+            yield env
+
+    def test_egg_base_installed_egg_info(self, tmpdir_cwd, env):
+        self._create_project()
+
+        environ = os.environ.copy().update(
+            HOME=env.paths['home'],
+        )
+        cmd = [
+            'install',
+            '--home', env.paths['home'],
+            '--install-lib', env.paths['lib'],
+            '--install-scripts', env.paths['scripts'],
+            '--install-data', env.paths['data'],
+        ]
+        code, data = environment.run_setup_py(
+            cmd=cmd,
+            pypath=os.pathsep.join([env.paths['lib'], str(tmpdir_cwd)]),
+            data_stream=1,
+            env=environ,
+        )
+        if code:
+            raise AssertionError(data)
 
-            actual = self._find_egg_info_files(paths['lib'])
+        actual = self._find_egg_info_files(env.paths['lib'])
 
-            expected = [
-                'PKG-INFO',
-                'SOURCES.txt',
-                'dependency_links.txt',
-                'entry_points.txt',
-                'not-zip-safe',
-                'top_level.txt',
-            ]
-            assert sorted(actual) == expected
+        expected = [
+            'PKG-INFO',
+            'SOURCES.txt',
+            'dependency_links.txt',
+            'entry_points.txt',
+            'not-zip-safe',
+            'top_level.txt',
+        ]
+        assert sorted(actual) == expected
 
     def _find_egg_info_files(self, root):
         results = (