zebra-report/test/sendbye-fsm.test.js

#!/usr/bin/env node
/* sendByeIfRealClose state-machine tests.
 *
 *     node test/sendbye-fsm.test.js
 *
 * Pins the listener / speaker split on pagehide(persisted=true):
 *
 *   - speaker  + persisted=true  -> no bye (bfcache nap; keep PCs warm)
 *   - speaker  + persisted=false -> bye (real unload)
 *   - listener + persisted=true  -> bye (no PCs to protect; roster
 *                                        cleanup matters more than
 *                                        bfcache continuity)
 *   - listener + persisted=false -> bye (real unload)
 *
 * Background: fox 2026-06-03 hit "phone leaving and coming back cannot
 * hear the music" when bye was always sent — the SFU eviction killed
 * the speaker's PCs and the resumed page couldn't recover them. The
 * fix was to skip bye on persisted=true. fox 2026-06-06 hit the
 * opposite: "closed firefox on both phones [they] are both still in
 * the list" because listeners are exempt from the server's
 * aliveJanitor and the bfcache skip left them as 120s+8s zombies. The
 * split below threads the needle. The function is extracted from
 * web/zebra-spaces.html at test time so the spec can't drift. */

const fs = require('fs');
const path = require('path');
const src = fs.readFileSync(path.join(__dirname, '..', 'web', 'zebra-spaces.html'), 'utf8');

function extractFn(re){
  const m = src.match(re);
  if (!m) throw new Error('could not find ' + re);
  let i = src.indexOf('{', m.index + m[0].length), depth = 0, j = i;
  for (; j < src.length; j++){
    if (src[j] === '{') depth++;
    else if (src[j] === '}') { if (--depth === 0) { j++; break; } }
  }
  return src.slice(m.index, j);
}

const sendByeSrc = extractFn(/function sendByeIfRealClose\(/);

/* Build a sandbox where myRole + ws are mutable so each scenario can
 * configure them, and ws.send is a spy that records every call. */
function makeHarness(initialRole){
  const sent = [];
  const ws = {
    readyState: 1,        /* OPEN — WebSocket.OPEN === 1 in browsers */
    send(msg){ sent.push(msg); },
  };
  const factory = new Function(
    'wsRef', 'WebSocket', 'initialRole',
    'let myRole = initialRole;\n' +
    'const ws = wsRef;\n' +
    sendByeSrc + '\n' +
    'return {\n' +
    '  setRole(r){ myRole = r; },\n' +
    '  setWsState(s){ ws.readyState = s; },\n' +
    '  sendByeIfRealClose,\n' +
    '};\n'
  );
  return { sent, ws, api: factory(ws, { OPEN: 1 }, initialRole) };
}

let pass = 0, fail = 0;
function test(name, fn){
  try { fn(); console.log('  ✓ ' + name); pass++; }
  catch (e){ console.log('  ✗ ' + name + ' — ' + (e.message || e)); fail++; }
}
function eq(a, b, msg){
  if (a !== b) throw new Error((msg || 'expected') + ' — got ' + JSON.stringify(a) + ' want ' + JSON.stringify(b));
}

console.log('sendByeIfRealClose:');

test('speaker + persisted=true (bfcache): bye NOT sent (PCs must survive the nap)', () => {
  const h = makeHarness('speaker');
  h.api.sendByeIfRealClose({ persisted: true });
  eq(h.sent.length, 0, 'no bye on bfcache');
});

test('speaker + persisted=false (real unload): bye sent', () => {
  const h = makeHarness('speaker');
  h.api.sendByeIfRealClose({ persisted: false });
  eq(h.sent.length, 1, 'bye sent');
  eq(JSON.parse(h.sent[0]).type, 'bye');
});

test('host + persisted=true (bfcache): bye NOT sent (host is a speaker role)', () => {
  const h = makeHarness('host');
  h.api.sendByeIfRealClose({ persisted: true });
  eq(h.sent.length, 0);
});

test('cohost + persisted=true (bfcache): bye NOT sent', () => {
  const h = makeHarness('cohost');
  h.api.sendByeIfRealClose({ persisted: true });
  eq(h.sent.length, 0);
});

test('listener + persisted=true (bfcache): bye SENT (no PCs to protect, roster cleanup wins)', () => {
  /* Pins the fox 2026-06-06 fix: closed Firefox on phone leaves listener
   * zombies because aliveJanitor exempts listeners + bfcache skip blocked
   * bye. Listeners ride opposite the speaker bfcache rule. */
  const h = makeHarness('listener');
  h.api.sendByeIfRealClose({ persisted: true });
  eq(h.sent.length, 1, 'bye sent on bfcache for listener');
  eq(JSON.parse(h.sent[0]).type, 'bye');
});

test('listener + persisted=false (real unload): bye sent', () => {
  const h = makeHarness('listener');
  h.api.sendByeIfRealClose({ persisted: false });
  eq(h.sent.length, 1);
});

test('any role + no event (defensive): bye sent', () => {
  /* Some browsers call event handlers with undefined. Don't crash. */
  const h = makeHarness('speaker');
  h.api.sendByeIfRealClose(undefined);
  eq(h.sent.length, 1, 'bye sent when event missing');
});

test('ws not open: no bye attempted (no throw, no send)', () => {
  const h = makeHarness('listener');
  h.api.setWsState(0);   /* CONNECTING */
  h.api.sendByeIfRealClose({ persisted: true });
  eq(h.sent.length, 0, 'no send while ws not open');
});

test('role flips to listener mid-session, then bfcache fires: bye sent', () => {
  /* a user promoted/demoted during the session — the role-at-pagehide
   * is what matters, not the role-at-join. */
  const h = makeHarness('speaker');
  h.api.setRole('listener');
  h.api.sendByeIfRealClose({ persisted: true });
  eq(h.sent.length, 1, 'bye sent under post-demote listener state');
});

console.log('');
console.log((fail === 0 ? 'PASS' : 'FAIL') + ' — ' + pass + ' passed, ' + fail + ' failed');
process.exit(fail === 0 ? 0 : 1);