2 # Copyright 2020 The Pigweed Authors
4 # Licensed under the Apache License, Version 2.0 (the "License"); you may not
5 # use this file except in compliance with the License. You may obtain a copy of
8 # https://www.apache.org/licenses/LICENSE-2.0
10 # Unless required by applicable law or agreed to in writing, software
11 # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 # License for the specific language governing permissions and limitations under
15 """Contains the Python decoder tests and generates C++ decoder tests."""
17 from typing import Iterator, List, NamedTuple, Tuple, Union
20 from pw_build.generated_tests import Context, PyTest, TestGenerator, GroupOrTest
21 from pw_build.generated_tests import parse_test_generation_args
22 from pw_hdlc.decode import Frame, FrameDecoder, FrameStatus, NO_ADDRESS
23 from pw_hdlc.protocol import frame_check_sequence as fcs
26 def _encode(address: int, control: int, data: bytes) -> bytes:
27 frame = bytearray([address, control]) + data
29 frame = frame.replace(b'\x7d', b'\x7d\x5d')
30 frame = frame.replace(b'\x7e', b'\x7d\x5e')
31 return b''.join([b'\x7e', frame, b'\x7e'])
34 class Expected(NamedTuple):
38 status: FrameStatus = FrameStatus.OK
41 def error(cls, status: FrameStatus):
42 assert status is not FrameStatus.OK
43 return cls(NO_ADDRESS, b'', b'', status)
45 def __eq__(self, other) -> bool:
46 """Define == so an Expected and a Frame can be compared."""
47 return (self.address == other.address and self.control == other.control
48 and self.data == other.data and self.status is other.status)
51 class ExpectedRaw(NamedTuple):
55 def __eq__(self, other) -> bool:
56 """Define == so an ExpectedRaw and a Frame can be compared."""
57 return (self.raw_encoded == other.raw_encoded
58 and self.status is other.status)
61 Expectation = Union[Expected, ExpectedRaw]
63 _PARTIAL = fcs(b'\x0ACmsg\x5e')
64 _ESCAPED_FLAG_TEST_CASE = (
65 b'\x7e\x0ACmsg\x7d\x7e' + _PARTIAL + b'\x7e',
67 Expected.error(FrameStatus.FRAMING_ERROR),
68 Expected.error(FrameStatus.FRAMING_ERROR),
72 TEST_CASES: Tuple[GroupOrTest[Tuple[bytes, List[Expectation]]], ...] = (
74 (_encode(0, 0, b''), [Expected(0, b'\0', b'')]),
75 (_encode(55, 0x99, b''), [Expected(55, b'\x99', b'')]),
76 (_encode(55, 0x99, b'') * 3, [Expected(55, b'\x99', b'')] * 3),
77 'Simple one-byte payload',
78 (_encode(0, 0, b'\0'), [Expected(0, b'\0', b'\0')]),
79 (_encode(123, 0, b'A'), [Expected(123, b'\0', b'A')]),
80 'Simple multi-byte payload',
81 (_encode(0, 0, b'Hello, world!'), [Expected(0, b'\0', b'Hello, world!')]),
82 (_encode(123, 0, b'\0\0\1\0\0'), [Expected(123, b'\0', b'\0\0\1\0\0')]),
83 'Escaped one-byte payload',
84 (_encode(1, 2, b'\x7e'), [Expected(1, b'\2', b'\x7e')]),
85 (_encode(1, 2, b'\x7d'), [Expected(1, b'\2', b'\x7d')]),
86 (_encode(1, 2, b'\x7e') + _encode(1, 2, b'\x7d'),
87 [Expected(1, b'\2', b'\x7e'),
88 Expected(1, b'\2', b'\x7d')]),
90 (_encode(0x7e, 0, b'A'), [Expected(0x7e, b'\0', b'A')]),
91 (_encode(0x7d, 0, b'B'), [Expected(0x7d, b'\0', b'B')]),
93 (_encode(0, 0x7e, b'C'), [Expected(0, b'\x7e', b'C')]),
94 (_encode(0, 0x7d, b'D'), [Expected(0, b'\x7d', b'D')]),
95 'Escaped address and control',
96 (_encode(0x7e, 0x7d, b'E'), [Expected(0x7e, b'\x7d', b'E')]),
97 (_encode(0x7d, 0x7e, b'F'), [Expected(0x7d, b'\x7e', b'F')]),
98 (_encode(0x7e, 0x7e, b'\x7e'), [Expected(0x7e, b'\x7e', b'\x7e')]),
99 'Multiple frames separated by single flag',
100 (_encode(0, 0, b'A')[:-1] + _encode(1, 2, b'123'),
101 [Expected(0, b'\0', b'A'),
102 Expected(1, b'\2', b'123')]),
103 (_encode(0xff, 0, b'Yo')[:-1] * 3 + b'\x7e',
104 [Expected(0xff, b'\0', b'Yo')] * 3),
105 'Ignore empty frames',
108 (b'\x7e\x7e' + _encode(1, 2, b'3') + b'\x7e' * 5,
109 [Expected(1, b'\2', b'3')]),
110 (b'\x7e' * 10 + _encode(1, 2, b':O') + b'\x7e' * 3 + _encode(3, 4, b':P'),
111 [Expected(1, b'\2', b':O'),
112 Expected(3, b'\4', b':P')]),
113 'Cannot escape flag',
114 (b'\x7e\xAA\x7d\x7e\xab\x00Hello' + fcs(b'\xab\0Hello') + b'\x7e', [
115 Expected.error(FrameStatus.FRAMING_ERROR),
116 Expected(0xab, b'\0', b'Hello'),
118 _ESCAPED_FLAG_TEST_CASE,
120 (b'\x7e1\x7e', [Expected.error(FrameStatus.FRAMING_ERROR)]),
121 (b'\x7e12\x7e', [Expected.error(FrameStatus.FRAMING_ERROR)]),
122 (b'\x7e12345\x7e', [Expected.error(FrameStatus.FRAMING_ERROR)]),
123 'Incorrect frame check sequence',
124 (b'\x7e123456\x7e', [Expected.error(FrameStatus.FCS_MISMATCH)]),
125 (b'\x7e\1\2msg\xff\xff\xff\xff\x7e',
126 [Expected.error(FrameStatus.FCS_MISMATCH)]),
127 (_encode(0xA, 0xB, b'???')[:-2] + _encode(1, 2, b'def'), [
128 Expected.error(FrameStatus.FCS_MISMATCH),
129 Expected(1, b'\2', b'def'),
131 'Invalid escape in address',
132 (b'\x7e\x7d\x7d\0' + fcs(b'\x5d\0') + b'\x7e',
133 [Expected.error(FrameStatus.FRAMING_ERROR)]),
134 'Invalid escape in control',
135 (b'\x7e\0\x7d\x7d' + fcs(b'\0\x5d') + b'\x7e',
136 [Expected.error(FrameStatus.FRAMING_ERROR)]),
137 'Invalid escape in data',
138 (b'\x7e\0\1\x7d\x7d' + fcs(b'\0\1\x5d') + b'\x7e',
139 [Expected.error(FrameStatus.FRAMING_ERROR)]),
140 'Frame ends with escape',
141 (b'\x7e\x7d\x7e', [Expected.error(FrameStatus.FRAMING_ERROR)]),
142 (b'\x7e\1\x7d\x7e', [Expected.error(FrameStatus.FRAMING_ERROR)]),
143 (b'\x7e\1\2abc\x7d\x7e', [Expected.error(FrameStatus.FRAMING_ERROR)]),
144 (b'\x7e\1\2abcd\x7d\x7e', [Expected.error(FrameStatus.FRAMING_ERROR)]),
145 (b'\x7e\1\2abcd1234\x7d\x7e', [Expected.error(FrameStatus.FRAMING_ERROR)]),
146 'Inter-frame data is only escapes',
147 (b'\x7e\x7d\x7e\x7d\x7e', [
148 Expected.error(FrameStatus.FRAMING_ERROR),
149 Expected.error(FrameStatus.FRAMING_ERROR),
151 (b'\x7e\x7d\x7d\x7e\x7d\x7d\x7e', [
152 Expected.error(FrameStatus.FRAMING_ERROR),
153 Expected.error(FrameStatus.FRAMING_ERROR),
155 'Data before first flag',
156 (b'\0\1' + fcs(b'\0\1'), []),
157 (b'\0\1' + fcs(b'\0\1') + b'\x7e',
158 [Expected.error(FrameStatus.FRAMING_ERROR)]),
159 'No frames emitted until flag',
160 (_encode(1, 2, b'3')[:-1], []),
161 (b'\x7e' + _encode(1, 2, b'3')[1:-1] * 2, []),
162 'Only flag and escape characters can be escaped',
163 (b'\x7e\x7d\0' + _encode(1, 2, b'3'),
164 [Expected.error(FrameStatus.FRAMING_ERROR),
165 Expected(1, b'\2', b'3')]),
166 (b'\x7e1234\x7da' + _encode(1, 2, b'3'),
167 [Expected.error(FrameStatus.FRAMING_ERROR),
168 Expected(1, b'\2', b'3')]),
169 'Invalid frame records raw data',
170 (b'Hello?~', [ExpectedRaw(b'Hello?', FrameStatus.FRAMING_ERROR)]),
171 (b'~~Hel\x7d\x7dlo~',
172 [ExpectedRaw(b'Hel\x7d\x7dlo', FrameStatus.FRAMING_ERROR)]),
173 (b'Hello?~~~~~', [ExpectedRaw(b'Hello?', FrameStatus.FRAMING_ERROR)]),
174 (b'~~~~Hello?~~~~~', [ExpectedRaw(b'Hello?', FrameStatus.FCS_MISMATCH)]),
175 (b'Hello?~~Goodbye~', [
176 ExpectedRaw(b'Hello?', FrameStatus.FRAMING_ERROR),
177 ExpectedRaw(b'Goodbye', FrameStatus.FCS_MISMATCH),
180 # Formatting for the above tuple is very slow, so disable yapf.
182 _TESTS = TestGenerator(TEST_CASES)
185 def _expected(frames: List[Frame]) -> Iterator[str]:
186 for i, frame in enumerate(frames, 1):
188 yield f' Frame(kDecodedFrame{i:02}),'
190 yield f' Status::DataLoss(), // Frame {i}'
194 #include "pw_hdlc/decoder.h"
200 #include "gtest/gtest.h"
201 #include "pw_bytes/array.h"
209 } // namespace pw::hdlc"""
212 def _cpp_test(ctx: Context) -> Iterator[str]:
213 """Generates a C++ test for the provided test data."""
214 data, _ = ctx.test_case
215 frames = list(FrameDecoder().process(data))
216 data_bytes = ''.join(rf'\x{byte:02x}' for byte in data)
218 yield f'TEST(Decoder, {ctx.cc_name()}) {{'
219 yield f' static constexpr auto kData = bytes::String("{data_bytes}");\n'
221 for i, frame in enumerate(frames, 1):
222 if frame.status is FrameStatus.OK:
223 frame_bytes = ''.join(rf'\x{byte:02x}'
224 for byte in frame.raw_decoded)
225 yield (f' static constexpr auto kDecodedFrame{i:02} = '
226 f'bytes::String("{frame_bytes}");')
228 yield f' // Frame {i}: {frame.status.value}'
232 expected = '\n'.join(_expected(frames)) or ' // No frames'
233 decoder_size = max(len(data), 8) # Make sure large enough for a frame
236 DecoderBuffer<{decoder_size}> decoder;
238 static constexpr std::array<std::variant<Frame, Status>, {len(frames)}> kExpected = {{
242 size_t decoded_frames = 0;
244 decoder.Process(kData, [&](const Result<Frame>& result) {{
245 ASSERT_LT(decoded_frames++, kExpected.size());
246 auto& expected = kExpected[decoded_frames - 1];
248 if (std::holds_alternative<Status>(expected)) {{
249 EXPECT_EQ(Status::DataLoss(), result.status());
251 ASSERT_EQ(OkStatus(), result.status());
253 const Frame& decoded_frame = result.value();
254 const Frame& expected_frame = std::get<Frame>(expected);
255 EXPECT_EQ(expected_frame.address(), decoded_frame.address());
256 EXPECT_EQ(expected_frame.control(), decoded_frame.control());
257 ASSERT_EQ(expected_frame.data().size(), decoded_frame.data().size());
258 EXPECT_EQ(std::memcmp(expected_frame.data().data(),
259 decoded_frame.data().data(),
260 expected_frame.data().size()),
265 EXPECT_EQ(decoded_frames, kExpected.size());
269 def _define_py_test(ctx: Context) -> PyTest:
270 data, expected_frames = ctx.test_case
272 def test(self) -> None:
274 self.assertEqual(expected_frames,
275 list(FrameDecoder().process(data)),
276 msg=f'{ctx.group}: {data!r}')
278 # Decode byte-by-byte
279 decoder = FrameDecoder()
280 decoded_frames: List[Frame] = []
281 for i in range(len(data)):
282 decoded_frames += decoder.process(data[i:i + 1])
284 self.assertEqual(expected_frames,
286 msg=f'{ctx.group} (byte-by-byte): {data!r}')
291 # Class that tests all cases in TEST_CASES.
292 DecoderTest = _TESTS.python_tests('DecoderTest', _define_py_test)
294 if __name__ == '__main__':
295 args = parse_test_generation_args()
296 if args.generate_cc_test:
297 _TESTS.cc_tests(args.generate_cc_test, _cpp_test, _CPP_HEADER,