From 5329aaa74bfe48a3be4fcd15d070bacfde682267 Mon Sep 17 00:00:00 2001 From: Robert Collins Date: Fri, 17 Jul 2015 20:08:45 +1200 Subject: Issue #21750: mock_open.read_data can now be read from each instance, as it could in Python 3.3. --- Lib/unittest/mock.py | 70 ++++++++++++++++++---------------- Lib/unittest/test/testmock/testmock.py | 5 +++ Lib/unittest/test/testmock/testwith.py | 18 ++++++++- Misc/NEWS | 3 ++ 4 files changed, 61 insertions(+), 35 deletions(-) diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py index c805726..2602e1b 100644 --- a/Lib/unittest/mock.py +++ b/Lib/unittest/mock.py @@ -2265,6 +2265,7 @@ def _iterate_read_data(read_data): for line in data_as_list: yield line + def mock_open(mock=None, read_data=''): """ A helper function to create a mock to replace the use of `open`. It works @@ -2277,24 +2278,6 @@ def mock_open(mock=None, read_data=''): `read_data` is a string for the `read` methoddline`, and `readlines` of the file handle to return. This is an empty string by default. """ - def _readlines_side_effect(*args, **kwargs): - if handle.readlines.return_value is not None: - return handle.readlines.return_value - return list(_data) - - def _read_side_effect(*args, **kwargs): - if handle.read.return_value is not None: - return handle.read.return_value - return ''.join(_data) - - def _readline_side_effect(): - if handle.readline.return_value is not None: - while True: - yield handle.readline.return_value - for line in _data: - yield line - - global file_spec if file_spec is None: import _io @@ -2303,21 +2286,42 @@ def mock_open(mock=None, read_data=''): if mock is None: mock = MagicMock(name='open', spec=open) - handle = MagicMock(spec=file_spec) - handle.__enter__.return_value = handle - - _data = _iterate_read_data(read_data) - - handle.write.return_value = None - handle.read.return_value = None - handle.readline.return_value = None - handle.readlines.return_value = None - - handle.read.side_effect = _read_side_effect - handle.readline.side_effect = _readline_side_effect() - handle.readlines.side_effect = _readlines_side_effect - - mock.return_value = handle + def make_handle(*args, **kwargs): + # Arg checking is handled by __call__ + def _readlines_side_effect(*args, **kwargs): + if handle.readlines.return_value is not None: + return handle.readlines.return_value + return list(_data) + + def _read_side_effect(*args, **kwargs): + if handle.read.return_value is not None: + return handle.read.return_value + return ''.join(_data) + + def _readline_side_effect(): + if handle.readline.return_value is not None: + while True: + yield handle.readline.return_value + for line in _data: + yield line + + handle = MagicMock(spec=file_spec) + handle.__enter__.return_value = handle + + _data = _iterate_read_data(read_data) + + handle.write.return_value = None + handle.read.return_value = None + handle.readline.return_value = None + handle.readlines.return_value = None + + handle.read.side_effect = _read_side_effect + handle.readline.side_effect = _readline_side_effect() + handle.readlines.side_effect = _readlines_side_effect + _check_and_set_parent(mock, handle, None, '()') + return handle + + mock.side_effect = make_handle return mock diff --git a/Lib/unittest/test/testmock/testmock.py b/Lib/unittest/test/testmock/testmock.py index 4fe6314..32703e6 100644 --- a/Lib/unittest/test/testmock/testmock.py +++ b/Lib/unittest/test/testmock/testmock.py @@ -1326,6 +1326,11 @@ class MockTest(unittest.TestCase): self.assertEqual(m.mock_calls, [call.__int__(), call.__float__()]) self.assertEqual(m.method_calls, []) + def test_mock_open_reuse_issue_21750(self): + mocked_open = mock.mock_open(read_data='data') + f1 = mocked_open('a-name') + f2 = mocked_open('another-name') + self.assertEqual(f1.read(), f2.read()) def test_mock_parents(self): for Klass in Mock, MagicMock: diff --git a/Lib/unittest/test/testmock/testwith.py b/Lib/unittest/test/testmock/testwith.py index f54e051..ddcfe77 100644 --- a/Lib/unittest/test/testmock/testwith.py +++ b/Lib/unittest/test/testmock/testwith.py @@ -141,7 +141,6 @@ class TestMockOpen(unittest.TestCase): def test_mock_open_context_manager(self): mock = mock_open() - handle = mock.return_value with patch('%s.open' % __name__, mock, create=True): with open('foo') as f: f.read() @@ -149,8 +148,23 @@ class TestMockOpen(unittest.TestCase): expected_calls = [call('foo'), call().__enter__(), call().read(), call().__exit__(None, None, None)] self.assertEqual(mock.mock_calls, expected_calls) - self.assertIs(f, handle) + # mock_open.return_value is no longer static, because + # readline support requires that it mutate state + def test_mock_open_context_manager_multiple_times(self): + mock = mock_open() + with patch('%s.open' % __name__, mock, create=True): + with open('foo') as f: + f.read() + with open('bar') as f: + f.read() + + expected_calls = [ + call('foo'), call().__enter__(), call().read(), + call().__exit__(None, None, None), + call('bar'), call().__enter__(), call().read(), + call().__exit__(None, None, None)] + self.assertEqual(mock.mock_calls, expected_calls) def test_explicit_mock(self): mock = MagicMock() diff --git a/Misc/NEWS b/Misc/NEWS index c0a5edf..2c669f3 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -66,6 +66,9 @@ Core and Builtins Library ------- +- Issue #21750: mock_open.read_data can now be read from each instance, as it + could in Python 3.3. + - Issue #23247: Fix a crash in the StreamWriter.reset() of CJK codecs. - Issue #18622: unittest.mock.mock_open().reset_mock would recurse infinitely. -- cgit v0.12