xref: /aosp_15_r20/external/pigweed/pw_hdlc/ts/encoder_test.ts (revision 61c4878ac05f98d0ceed94b57d316916de578985) 
1// Copyright 2022 The Pigweed Authors
2//
3// Licensed under the Apache License, Version 2.0 (the "License"); you may not
4// use this file except in compliance with the License. You may obtain a copy of
5// the License at
6//
7//     https://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, WITHOUT
11// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12// License for the specific language governing permissions and limitations under
13// the License.
14
15/* eslint-env browser */
16
17import { Encoder } from './encoder';
18import * as protocol from './protocol';
19import * as util from './util';
20
21const FLAG = Uint8Array.from([protocol.FLAG]);
22
23function withFCS(data: Uint8Array): Uint8Array {
24  return util.concatenate(data, protocol.frameCheckSequence(data));
25}
26
27function withFlags(data: Uint8Array): Uint8Array {
28  return util.concatenate(FLAG, data, FLAG);
29}
30
31describe('Encoder', () => {
32  let encoder: Encoder;
33  let textEncoder: TextEncoder;
34
35  beforeEach(() => {
36    encoder = new Encoder();
37    textEncoder = new TextEncoder();
38  });
39
40  it('creates frame for empty data', () => {
41    const data = textEncoder.encode('');
42    expect(encoder.uiFrame(0, data)).toEqual(
43      withFlags(withFCS(new Uint8Array([0x01, 0x03]))),
44    );
45    expect(encoder.uiFrame(0x1a, data)).toEqual(
46      withFlags(withFCS(new Uint8Array([0x35, 0x03]))),
47    );
48    expect(encoder.uiFrame(0x1a, data)).toEqual(
49      withFlags(withFCS(textEncoder.encode('\x35\x03'))),
50    );
51  });
52
53  it('creates frame for one byte', () => {
54    const data = textEncoder.encode('A');
55    expect(encoder.uiFrame(0, data)).toEqual(
56      withFlags(withFCS(textEncoder.encode('\x01\x03A'))),
57    );
58  });
59
60  it('creates frame for multibyte data', () => {
61    const data = textEncoder.encode('123456789');
62    expect(encoder.uiFrame(0, data)).toEqual(
63      withFlags(withFCS(textEncoder.encode('\x01\x03123456789'))),
64    );
65  });
66
67  it('creates frame for multibyte data with address', () => {
68    const data = textEncoder.encode('123456789');
69    expect(encoder.uiFrame(128, data)).toEqual(
70      withFlags(withFCS(textEncoder.encode('\x00\x03\x03123456789'))),
71    );
72  });
73
74  it('creates frame for data with escape sequence', () => {
75    const data = textEncoder.encode('\x7d');
76    const expectedContent = util.concatenate(
77      textEncoder.encode('\x7d\x5d\x03\x7d\x5d'),
78      protocol.frameCheckSequence(textEncoder.encode('\x7d\x03\x7d')),
79    );
80    expect(encoder.uiFrame(0x3e, data)).toEqual(withFlags(expectedContent));
81
82    const data2 = textEncoder.encode('A\x7e\x7dBC');
83    const expectedContent2 = util.concatenate(
84      textEncoder.encode('\x7d\x5d\x03A\x7d\x5e\x7d\x5dBC'),
85      protocol.frameCheckSequence(textEncoder.encode('\x7d\x03A\x7e\x7dBC')),
86    );
87    expect(encoder.uiFrame(0x3e, data2)).toEqual(withFlags(expectedContent2));
88  });
89
90  it('Computes frameCheckSequence correctly', () => {
91    expect(
92      protocol.frameCheckSequence(textEncoder.encode('\x7d\x03A\x7e\x7dBC')),
93    ).toEqual(new Uint8Array([195, 124, 135, 9]));
94    expect(
95      protocol.frameCheckSequence(textEncoder.encode('\x7d\x5d\x03\x7d\x5d')),
96    ).toEqual(new Uint8Array([183, 144, 10, 115]));
97    expect(
98      protocol.frameCheckSequence(textEncoder.encode('\x7d\x03\x7d')),
99    ).toEqual(new Uint8Array([83, 124, 241, 166]));
100    expect(
101      protocol.frameCheckSequence(textEncoder.encode('hello pigweed')),
102    ).toEqual(new Uint8Array([34, 22, 236, 2]));
103  });
104});
105