# Copyright 2024 Google LLC # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. import os import sys import tempfile import unittest # Allow us to run even if not at the `tools` directory. root_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), os.pardir)) sys.path.insert(0, root_dir) from hdlc import HDLCDecoder, hdlc_encode_data class TestHDLCDecode(unittest.TestCase): def test_line_noise(self): decoder = HDLCDecoder() decoder.write(b'This is a bunch') decoder.write(b'of line noise!!\x7e') decoder.write(b'\x7eFollowed by a valid frame\x7e') self.assertEquals(decoder.get_frame(), 'Followed by a valid frame') self.assertIsNone(decoder.get_frame()) def test_segmented_frames(self): decoder = HDLCDecoder() decoder.write(b'\x7eFrame ') decoder.write(b'one\x7eFrame two') decoder.write(b'\x7eFrame thr') decoder.write(b'ee\x7e') self.assertEquals(decoder.get_frame(), 'Frame one') self.assertEquals(decoder.get_frame(), 'Frame two') self.assertEquals(decoder.get_frame(), 'Frame three') self.assertIsNone(decoder.get_frame()) def test_empty(self): decoder = HDLCDecoder() decoder.write(b'\x7e\x7e\x7e\x7e') self.assertIsNone(decoder.get_frame()) def test_escape(self): decoder = HDLCDecoder() decoder.write(b'\x7eHow about escaping?\x7d\x5e\x7e') decoder.write(b'\x7eAny ch\x7dArac\x7dTer can be \x7dE\x7dS\x7dC\x7dA\x7dPed!\x7e') decoder.write(b'\x7eEven a \x7d\x7d\x7e') self.assertEquals(decoder.get_frame(), 'How about escaping?\x7e') self.assertEquals(decoder.get_frame(), 'Any character can be escaped!') self.assertEquals(decoder.get_frame(), 'Even a \x5d') self.assertIsNone(decoder.get_frame()) def test_invalid(self): decoder = HDLCDecoder() decoder.write(b'\x7eInvalid termination\x7d\x7e') decoder.write(b'\x7eI am valid\x7e') decoder.write(b'partial frame') self.assertEquals(decoder.get_frame(), 'I am valid') self.assertIsNone(decoder.get_frame()) class TestHDLCEncodeData(unittest.TestCase): def test_simple(self): self.assertEquals(hdlc_encode_data('This is easy'), '\x7eThis is easy\x7e') def test_escape(self): self.assertEquals(hdlc_encode_data('Escape \x7d\x7e!'), '\x7eEscape \x7d\x5d\x7d\x5e!\x7e') def test_empty(self): self.assertEquals(hdlc_encode_data(''), '\x7e\x7e') if __name__ == '__main__': unittest.main()