Use mock for monkeypatching instead of handcoding it

IPython/core/tests/test_paths.py

@@ -1,4 +1,3 b''
-from contextlib import contextmanager
 import errno
 import os
 import shutil
@@ -6,21 +5,18 b' import sys'
 import tempfile
 import warnings
 
-try:
-    reload
-except NameError:   # Python 3
-    from imp import reload
+try:                    # Python 3
+    from unittest.mock import patch
+except ImportError:     # Python 2
+    from mock import patch
 
-from nose import with_setup
 import nose.tools as nt
 from testpath import modified_env
 
-import IPython
 from IPython import paths
 from IPython.testing.decorators import skip_win32
 from IPython.utils.tempdir import TemporaryDirectory
 
-env = os.environ
 TMP_TEST_DIR = tempfile.mkdtemp()
 HOME_TEST_DIR = os.path.join(TMP_TEST_DIR, "home_test_dir")
 XDG_TEST_DIR = os.path.join(HOME_TEST_DIR, "xdg_test_dir")
@@ -49,89 +45,57 b' def teardown():'
     # that non-empty directories are all recursively removed.
     shutil.rmtree(TMP_TEST_DIR)
 
-
-def setup_environment():
-    """Setup testenvironment for some functions that are tested
-    in this module. In particular this functions stores attributes
-    and other things that we need to stub in some test functions.
-    This needs to be done on a function level and not module level because
-    each testfunction needs a pristine environment.
-    """
-    global oldstuff
-    oldstuff = (os.name, sys.platform, paths.get_home_dir, IPython.__file__, os.getcwd())
-
-def teardown_environment():
-    """Restore things that were remembered by the setup_environment function
-    """
-    (os.name, sys.platform, paths.get_home_dir, IPython.__file__, old_wd) = oldstuff
-    os.chdir(old_wd)
-    reload(paths)
-
-    if hasattr(sys, 'frozen'):
-        del sys.frozen
-
-# Build decorator that uses the setup_environment/setup_environment
-with_environment = with_setup(setup_environment, teardown_environment)
-
-@contextmanager
 def patch_get_home_dir(dirpath):
-    orig_get_home_dir = paths.get_home_dir
-    paths.get_home_dir = lambda : dirpath
-    try:
-        yield
-    finally:
-        paths.get_home_dir = orig_get_home_dir
+    return patch.object(paths, 'get_home_dir', return_value=dirpath)
+
 
 def test_get_ipython_dir_1():
     """test_get_ipython_dir_1, Testcase to see if we can call get_ipython_dir without Exceptions."""
     env_ipdir = os.path.join("someplace", ".ipython")
-    paths._writable_dir = lambda path: True
-    with modified_env({'IPYTHONDIR': env_ipdir}):
+    with patch.object(paths, '_writable_dir', return_value=True), \
+            modified_env({'IPYTHONDIR': env_ipdir}):
         ipdir = paths.get_ipython_dir()
 
     nt.assert_equal(ipdir, env_ipdir)
 
-@with_environment
 def test_get_ipython_dir_2():
     """test_get_ipython_dir_2, Testcase to see if we can call get_ipython_dir without Exceptions."""
-    with patch_get_home_dir('someplace'):
-        paths.get_xdg_dir = lambda : None
-        paths._writable_dir = lambda path: True
-        os.name = "posix"
-        with modified_env({'IPYTHON_DIR': None,
-                           'IPYTHONDIR': None,
-                           'XDG_CONFIG_HOME': None
-                          }):
-            ipdir = paths.get_ipython_dir()
+    with patch_get_home_dir('someplace'), \
+            patch.object(paths, 'get_xdg_dir', return_value=None), \
+            patch.object(paths, '_writable_dir', return_value=True), \
+            patch('os.name', "posix"), \
+            modified_env({'IPYTHON_DIR': None,
+                          'IPYTHONDIR': None,
+                          'XDG_CONFIG_HOME': None
+                         }):
+        ipdir = paths.get_ipython_dir()
 
-        nt.assert_equal(ipdir, os.path.join("someplace", ".ipython"))
+    nt.assert_equal(ipdir, os.path.join("someplace", ".ipython"))
 
-@with_environment
 def test_get_ipython_dir_3():
     """test_get_ipython_dir_3, move XDG if defined, and .ipython doesn't exist."""
     tmphome = TemporaryDirectory()
     try:
-        with patch_get_home_dir(tmphome.name):
-            os.name = "posix"
-            with modified_env({
-                'IPYTHON_DIR': None,
-                'IPYTHONDIR': None,
-                'XDG_CONFIG_HOME': XDG_TEST_DIR,
-            }), warnings.catch_warnings(record=True) as w:
-                ipdir = paths.get_ipython_dir()
+        with patch_get_home_dir(tmphome.name), \
+                patch('os.name', 'posix'), \
+                modified_env({
+                    'IPYTHON_DIR': None,
+                    'IPYTHONDIR': None,
+                    'XDG_CONFIG_HOME': XDG_TEST_DIR,
+                }), warnings.catch_warnings(record=True) as w:
+            ipdir = paths.get_ipython_dir()
 
-            nt.assert_equal(ipdir, os.path.join(tmphome.name, ".ipython"))
-            if sys.platform != 'darwin':
-                nt.assert_equal(len(w), 1)
-                nt.assert_in('Moving', str(w[0]))
+        nt.assert_equal(ipdir, os.path.join(tmphome.name, ".ipython"))
+        if sys.platform != 'darwin':
+            nt.assert_equal(len(w), 1)
+            nt.assert_in('Moving', str(w[0]))
     finally:
         tmphome.cleanup()
 
-@with_environment
 def test_get_ipython_dir_4():
     """test_get_ipython_dir_4, warn if XDG and home both exist."""
-    with patch_get_home_dir(HOME_TEST_DIR):
-        os.name = "posix"
+    with patch_get_home_dir(HOME_TEST_DIR), \
+            patch('os.name', 'posix'):
         try:
             os.mkdir(os.path.join(XDG_TEST_DIR, 'ipython'))
         except OSError as e:
@@ -151,11 +115,10 b' def test_get_ipython_dir_4():'
             nt.assert_equal(len(w), 1)
             nt.assert_in('Ignoring', str(w[0]))
 
-@with_environment
 def test_get_ipython_dir_5():
     """test_get_ipython_dir_5, use .ipython if exists and XDG defined, but doesn't exist."""
-    with patch_get_home_dir(HOME_TEST_DIR):
-        os.name = "posix"
+    with patch_get_home_dir(HOME_TEST_DIR), \
+            patch('os.name', 'posix'):
         try:
             os.rmdir(os.path.join(XDG_TEST_DIR, 'ipython'))
         except OSError as e:
@@ -171,55 +134,46 b' def test_get_ipython_dir_5():'
 
         nt.assert_equal(ipdir, IP_TEST_DIR)
 
-@with_environment
 def test_get_ipython_dir_6():
     """test_get_ipython_dir_6, use home over XDG if defined and neither exist."""
     xdg = os.path.join(HOME_TEST_DIR, 'somexdg')
     os.mkdir(xdg)
     shutil.rmtree(os.path.join(HOME_TEST_DIR, '.ipython'))
-    with patch_get_home_dir(HOME_TEST_DIR):
-        orig_get_xdg_dir = paths.get_xdg_dir
-        paths.get_xdg_dir = lambda : xdg
-        try:
-            os.name = "posix"
-            with modified_env({
+    print(paths._writable_dir)
+    with patch_get_home_dir(HOME_TEST_DIR), \
+            patch.object(paths, 'get_xdg_dir', return_value=xdg), \
+            patch('os.name', 'posix'), \
+            modified_env({
                 'IPYTHON_DIR': None,
                 'IPYTHONDIR': None,
                 'XDG_CONFIG_HOME': None,
             }), warnings.catch_warnings(record=True) as w:
-                ipdir = paths.get_ipython_dir()
+        ipdir = paths.get_ipython_dir()
 
-            nt.assert_equal(ipdir, os.path.join(HOME_TEST_DIR, '.ipython'))
-            nt.assert_equal(len(w), 0)
-        finally:
-            paths.get_xdg_dir = orig_get_xdg_dir
+    nt.assert_equal(ipdir, os.path.join(HOME_TEST_DIR, '.ipython'))
+    nt.assert_equal(len(w), 0)
 
 def test_get_ipython_dir_7():
     """test_get_ipython_dir_7, test home directory expansion on IPYTHONDIR"""
-    paths._writable_dir = lambda path: True
     home_dir = os.path.normpath(os.path.expanduser('~'))
-    with modified_env({'IPYTHONDIR': os.path.join('~', 'somewhere')}):
+    with modified_env({'IPYTHONDIR': os.path.join('~', 'somewhere')}), \
+            patch.object(paths, '_writable_dir', return_value=True):
         ipdir = paths.get_ipython_dir()
     nt.assert_equal(ipdir, os.path.join(home_dir, 'somewhere'))
 
 @skip_win32
 def test_get_ipython_dir_8():
     """test_get_ipython_dir_8, test / home directory"""
-    old = paths._writable_dir, paths.get_xdg_dir
-    try:
-        paths._writable_dir = lambda path: bool(path)
-        paths.get_xdg_dir = lambda: None
-        with modified_env({
-            'IPYTHON_DIR': None,
-            'IPYTHONDIR': None,
-            'HOME': '/',
-        }):
-            nt.assert_equal(paths.get_ipython_dir(), '/.ipython')
-    finally:
-        paths._writable_dir, paths.get_xdg_dir = old
+    with patch.object(paths, '_writable_dir', lambda path: bool(path)), \
+            patch.object(paths, 'get_xdg_dir', return_value=None), \
+            modified_env({
+                'IPYTHON_DIR': None,
+                'IPYTHONDIR': None,
+                'HOME': '/',
+            }):
+        nt.assert_equal(paths.get_ipython_dir(), '/.ipython')
 
 
-@with_environment
 def test_get_ipython_cache_dir():
     with modified_env({'HOME': HOME_TEST_DIR}):
         if os.name == 'posix' and sys.platform != 'darwin':