BetterDesk/web-nodejs/tests/wsRelay.framing.test.js

'use strict';

const { _relayFraming } = require('../services/wsRelay');

describe('wsRelay RustDesk message/TCP framing bridge', () => {
    test('round-trips fragmented BytesCodec frames at every header size', () => {
        const sizes = [1, 63, 64, 16383, 16384, 0x400000];
        const payloads = sizes.map((size, index) => Buffer.alloc(size, index + 1));
        const stream = Buffer.concat(payloads.map(_relayFraming.encodeRelayFrame));
        const decoder = _relayFraming.createRelayFrameDecoder();
        const decoded = [];

        const chunkSizes = [1, 2, 7, 31, 257, 4096, 65535];
        let offset = 0;
        let chunkIndex = 0;
        while (offset < stream.length) {
            const end = Math.min(stream.length, offset + chunkSizes[chunkIndex % chunkSizes.length]);
            decoded.push(...decoder.feed(stream.subarray(offset, end)));
            offset = end;
            chunkIndex++;
        }

        expect(decoded).toHaveLength(payloads.length);
        decoded.forEach((payload, index) => {
            expect(payload.equals(payloads[index])).toBe(true);
        });
    });

    test('round-trips an empty RustDesk raw payload', () => {
        const frame = _relayFraming.encodeRelayFrame(Buffer.alloc(0));
        expect(frame).toEqual(Buffer.from([0]));

        const decoder = _relayFraming.createRelayFrameDecoder();
        const decoded = decoder.feed(frame);
        expect(decoded).toHaveLength(1);
        expect(decoded[0]).toHaveLength(0);
    });

    test('accepts a fragmented zero-length TCP frame', () => {
        const decoder = _relayFraming.createRelayFrameDecoder();
        expect(decoder.feed(Buffer.from([0]))).toEqual([Buffer.alloc(0)]);
    });
});