Issue #21750: mock_open.read_data can now be read from each instance, as it
could in Python 3.3.
diff --git a/NEWS b/NEWS
index 90897a2..f3f0086 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,9 @@
+Library
+-------
+
+- Issue #21750: mock_open.read_data can now be read from each instance, as it
+ could in Python 3.3.
+
- Issue #18622: unittest.mock.mock_open().reset_mock would recurse infinitely.
Patch from Nicola Palumbo and Laurent De Buyst.
diff --git a/mock/mock.py b/mock/mock.py
index cd90dea..12016d4 100644
--- a/mock/mock.py
+++ b/mock/mock.py
@@ -2453,6 +2453,7 @@
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
@@ -2495,21 +2496,42 @@
if mock is None:
mock = MagicMock(name='open', spec=open)
- handle = MagicMock(spec=file_spec)
- handle.__enter__.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)
- _data = _iterate_read_data(read_data)
+ def _read_side_effect(*args, **kwargs):
+ if handle.read.return_value is not None:
+ return handle.read.return_value
+ return ''.join(_data)
- handle.write.return_value = None
- handle.read.return_value = None
- handle.readline.return_value = None
- handle.readlines.return_value = None
+ 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.read.side_effect = _read_side_effect
- handle.readline.side_effect = _readline_side_effect()
- handle.readlines.side_effect = _readlines_side_effect
+ handle = MagicMock(spec=file_spec)
+ handle.__enter__.return_value = handle
- mock.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/mock/tests/testmock.py b/mock/tests/testmock.py
index 4be8779..88f94f3 100644
--- a/mock/tests/testmock.py
+++ b/mock/tests/testmock.py
@@ -1436,6 +1436,11 @@
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/mock/tests/testwith.py b/mock/tests/testwith.py
index 25d706f..11e97bb 100644
--- a/mock/tests/testwith.py
+++ b/mock/tests/testwith.py
@@ -146,7 +146,6 @@
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()
@@ -154,8 +153,23 @@
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()
