Clean up test_return_code tests slightly

This is a refinement on the previous commit to reduce unecessary changes
to the functional tests in the test_return_codes module. Mainly always
decoding the output from the subprocess for testing broken things
unexpectedly when a bytes object was expected.

stestr/tests/test_return_codes.py

@@ -81,25 +81,21 @@ def _add_dict(test):
         self.assertThat(len(tests), testtools.matchers.GreaterThan(0))
 
     def assertRunExit(self, cmd, expected, subunit=False, stdin=None):
-        env = os.environ
         if stdin:
             p = subprocess.Popen(
                 "%s" % cmd, shell=True, stdin=subprocess.PIPE,
-                stdout=subprocess.PIPE, stderr=subprocess.PIPE,
-                env=env)
+                stdout=subprocess.PIPE, stderr=subprocess.PIPE)
             out, err = p.communicate(stdin)
         else:
             p = subprocess.Popen(
                 "%s" % cmd, shell=True,
-                stdout=subprocess.PIPE, stderr=subprocess.PIPE,
-                env=env)
+                stdout=subprocess.PIPE, stderr=subprocess.PIPE)
             out, err = p.communicate()
         if not subunit:
-            out = out.decode('utf8')
-            err = err.decode('utf8')
             self.assertEqual(
                 p.returncode, expected,
-                "Stdout: %s; Stderr: %s" % (out, err))
+                "Stdout: %s; Stderr: %s" % (out.decode('utf8'),
+                                            err.decode('utf8')))
             return (out, err)
         else:
             self.assertEqual(p.returncode, expected,
@@ -239,10 +235,8 @@ def test_list(self):
         self.assertRunExit('stestr list', 0)
 
     def _get_cmd_stdout(self, cmd):
-        env = os.environ
         p = subprocess.Popen(cmd, shell=True,
-                             stdout=subprocess.PIPE,
-                             env=env)
+                             stdout=subprocess.PIPE)
         out = p.communicate()
         self.assertEqual(0, p.returncode)
         return out
@@ -297,14 +291,14 @@ def test_load_force_init_invalid(self):
     def test_load_from_stdin_quiet(self):
         out, err = self.assertRunExit('stestr --user-config stestr.yaml -q '
                                       'run passing', 0)
-        self.assertEqual(out, '')
+        self.assertEqual('', out.decode('utf-8'))
         # FIXME(masayukig): We get some warnings when we run a coverage job.
         # So, just ignore 'err' here.
         stream = self._get_cmd_stdout('stestr last --subunit')[0]
         out, err = self.assertRunExit('stestr --user-config stestr.yaml -q '
                                       'load', 0, stdin=stream)
-        self.assertEqual(out, '')
-        self.assertEqual(err, '')
+        self.assertEqual(out.decode('utf-8'), '')
+        self.assertEqual(err.decode('utf-8'), '')
 
     def test_no_subunit_trace_force_subunit_trace(self):
         out, err = self.assertRunExit(
@@ -394,29 +388,29 @@ def test_list_from_func(self):
     def test_run_no_discover_pytest_path(self):
         passing_string = 'tests/test_passing.py::FakeTestClass::test_pass_list'
         out, err = self.assertRunExit('stestr run -n %s' % passing_string, 0)
-        lines = out.splitlines()
+        lines = out.decode('utf8').splitlines()
         self.assertIn(' - Passed: 1', lines)
         self.assertIn(' - Failed: 0', lines)
 
     def test_run_no_discover_pytest_path_failing(self):
         passing_string = 'tests/test_failing.py::FakeTestClass::test_pass_list'
         out, err = self.assertRunExit('stestr run -n %s' % passing_string, 1)
-        lines = out.splitlines()
+        lines = out.decode('utf8').splitlines()
         self.assertIn(' - Passed: 0', lines)
         self.assertIn(' - Failed: 1', lines)
 
     def test_run_no_discover_file_path(self):
         passing_string = 'tests/test_passing.py'
         out, err = self.assertRunExit('stestr run -n %s' % passing_string, 0)
-        lines = out.splitlines()
+        lines = out.decode('utf8').splitlines()
         self.assertIn(' - Passed: 2', lines)
         self.assertIn(' - Failed: 0', lines)
         self.assertIn(' - Expected Fail: 1', lines)
 
     def test_run_no_discover_file_path_failing(self):
         passing_string = 'tests/test_failing.py'
         out, err = self.assertRunExit('stestr run -n %s' % passing_string, 1)
-        lines = out.splitlines()
+        lines = out.decode('utf8').splitlines()
         self.assertIn(' - Passed: 0', lines)
         self.assertIn(' - Failed: 2', lines)
         self.assertIn(' - Unexpected Success: 1', lines)