1# Copyright 2015 gRPC authors.
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7#     http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14"""Utilities for testing stream-related code."""
15
16from grpc.framework.foundation import stream
17
18
19class TestConsumer(stream.Consumer):
20    """A stream.Consumer instrumented for testing.
21
22  Attributes:
23    calls: A sequence of value-termination pairs describing the history of calls
24      made on this object.
25  """
26
27    def __init__(self):
28        self.calls = []
29
30    def consume(self, value):
31        """See stream.Consumer.consume for specification."""
32        self.calls.append((value, False))
33
34    def terminate(self):
35        """See stream.Consumer.terminate for specification."""
36        self.calls.append((None, True))
37
38    def consume_and_terminate(self, value):
39        """See stream.Consumer.consume_and_terminate for specification."""
40        self.calls.append((value, True))
41
42    def is_legal(self):
43        """Reports whether or not a legal sequence of calls has been made."""
44        terminated = False
45        for value, terminal in self.calls:
46            if terminated:
47                return False
48            elif terminal:
49                terminated = True
50            elif value is None:
51                return False
52        else:  # pylint: disable=useless-else-on-loop
53            return True
54
55    def values(self):
56        """Returns the sequence of values that have been passed to this Consumer."""
57        return [value for value, _ in self.calls if value]
58