def exercise_seek_and_read(self):
self.create_file_object(mode="rb")
instrumented_file = mock.Mock(spec=self.file_object,
wraps=self.file_object)
words = ext.read_and_seek(streambuf(instrumented_file))
assert words == b"should, should, uld, ding, fun, [ eof ]"
n = streambuf.default_buffer_size
soughts = instrumented_file.seek.call_args_list
# stringent tests carefully crafted to make sure the seek-in-buffer
# optimisation works as expected
# C.f. the comment in the C++ function actual_write_test
assert soughts[-1] == mock.call(-4, 2)
soughts = soughts[:-1]
if n >= 14:
assert soughts == []
else:
assert soughts[0] == mock.call(6, 0)
soughts = soughts[1:]
if 8 <= n <= 13:
assert len(soughts) == 1 and self.only_seek_cur(soughts)
elif n == 7:
assert len(soughts) == 2 and self.only_seek_cur(soughts)
else:
assert soughts[0] == mock.call(6, 0)
soughts = soughts[1:]
assert self.only_seek_cur(soughts)
if n == 4:
assert len(soughts) == 1
else:
assert len(soughts) == 2
self.file_object.close()
def exercise_partial_read(self):
self.create_file_object(mode="rb")
words = ext.partial_read(streambuf(self.file_object))
assert words == b"Coding, should, "
trailing = self.file_object.read()
assert trailing == b" be fun"
self.file_object.close()
def exercise_read_failure(self):
self.create_file_object(mode="rb")
self.file_object.close()
with pytest.raises(ValueError):
ext.read_word(streambuf(self.file_object))
self.file_object.close()
def exercise_read(self):
self.create_file_object(mode="rb")
words = ext.read_word(streambuf(self.file_object))
assert words == b"Coding, should, be, fun, [ fail, eof ]"
self.file_object.close()
def exercise_write_failure(self):
self.create_file_object(mode="rb")
with pytest.raises(IOError):
ext.write_word(streambuf(self.file_object))
self.file_object.close()
