1 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 # Use of this source code is governed by a BSD-style license that can be
3 # found in the LICENSE file.
4 """A very very simple mock object harness."""
8 class MockFunctionCall(object):
9 def __init__(self, name):
12 self.return_value = None
13 self.when_called_handlers = []
15 def WithArgs(self, *args):
19 def WillReturn(self, value):
20 self.return_value = value
23 def WhenCalled(self, handler):
24 self.when_called_handlers.append(handler)
26 def VerifyEquals(self, got):
27 if self.name != got.name:
28 raise Exception('Self %s, got %s' % (repr(self), repr(got)))
29 if len(self.args) != len(got.args):
30 raise Exception('Self %s, got %s' % (repr(self), repr(got)))
31 for i in range(len(self.args)):
34 if self_a == DONT_CARE:
37 raise Exception('Self %s, got %s' % (repr(self), repr(got)))
44 args_text = ', '.join([arg_to_text(a) for a in self.args])
45 if self.return_value in (None, DONT_CARE):
46 return '%s(%s)' % (self.name, args_text)
47 return '%s(%s)->%s' % (self.name, args_text, repr(self.return_value))
49 class MockTrace(object):
51 self.expected_calls = []
52 self.next_call_index = 0
54 class MockObject(object):
55 def __init__(self, parent_mock = None):
57 self._trace = parent_mock._trace # pylint: disable=W0212
59 self._trace = MockTrace()
61 def __setattr__(self, name, value):
62 if (not hasattr(self, '_trace') or
63 hasattr(value, 'is_hook')):
64 object.__setattr__(self, name, value)
66 assert isinstance(value, MockObject)
67 object.__setattr__(self, name, value)
69 def ExpectCall(self, func_name, *args):
70 assert self._trace.next_call_index == 0
71 if not hasattr(self, func_name):
72 self._install_hook(func_name)
74 call = MockFunctionCall(func_name)
75 self._trace.expected_calls.append(call)
79 def _install_hook(self, func_name):
80 def handler(*args, **_):
81 got_call = MockFunctionCall(
82 func_name).WithArgs(*args).WillReturn(DONT_CARE)
83 if self._trace.next_call_index >= len(self._trace.expected_calls):
85 'Call to %s was not expected, at end of programmed trace.' %
87 expected_call = self._trace.expected_calls[
88 self._trace.next_call_index]
89 expected_call.VerifyEquals(got_call)
90 self._trace.next_call_index += 1
91 for h in expected_call.when_called_handlers:
93 return expected_call.return_value
94 handler.is_hook = True
95 setattr(self, func_name, handler)