feedBack/tests/js/song_close.test.js
Byron Gamatos 545e569ad6
refactor(app): carve the song session out of app.js — playSong, showScreen, closeCurrentSong (R3d) (#921)
36 declarations + the 4 autoplay/auto-exit gate statements. 359 lines.
app.js 3,772 -> 3,242. Bodies VERBATIM.

━━━ THIS WAS "THE UNCUTTABLE HEART", AND IT IS 359 LINES ━━━

At the start of this epic, seeding a dependency closure from count-in, from loops, from
section-practice, or from the JUCE seek shim all returned the SAME 178-function, 3,360-line set.
playSong and showScreen called each other; everything called them; nothing could be cut anywhere.
The conclusion — correct at the time — was that NO closure-based carve could touch it at any
seed, and the answer was a host seam.

That was true THEN. Every slice taken out since (transport, loops, count-in, section-practice,
the library, the edit modal, settings) removed edges, and the strongly-connected component
DISSOLVED. This closure is 36 declarations with an interface width of FOUR.

The lesson is not that the seam was wrong — the seam is what MADE this possible, by letting the
carves proceed against a cyclic core instead of stalling on it. The lesson is to RE-MEASURE. An
SCC is a fact about a graph at a moment, not a property of the code.

━━━ THE BUG NO SCAN COULD SEE, AND THE A/B DID ━━━

First cut passed every gate — no-undef clean, no-cycle clean, 1045/1045, pytest green — and
THREW IN THE BROWSER: "Assignment to constant variable."

window.feedBack.holdAutoplay / holdAutoExit and their two event handlers are TOP-LEVEL
STATEMENTS, not declarations. They WRITE this cluster's state (_autoplayHeld, _autoExitTimer, …),
and an imported binding is READ-ONLY — so left behind in app.js, every one threw the instant the
module existed.

A dependency scan that walks DECLARATIONS cannot see them. Mine didn't. This is the same blind
spot that nearly shipped a dead library A-Z rail (#896): app.js keeps its public API in top-level
statements, and a call-graph is blind to every one of them.

The extractor now finds them by construction — any top-level statement that WRITES a moved
binding comes with the carve — and the gate statements live beside the machinery they drive,
which is where they belonged anyway.

━━━ ZERO OUTSIDE WRITES, BY MOVING THE BOUNDARY RATHER THAN BUILDING MACHINERY ━━━

The autoplay scalars and the wake-lock state were written from outside the cluster, which would
have forced a setter or a state container. But the writers — _releaseAutoplay, _acquireWakeLock —
plainly belong here. Pulling them in left ZERO outside writes, so every export is a plain import.
Same move as settings (#920): measure the writers before you reach for a container.

VERIFIED. A/B against origin/main in two browsers, IDENTICAL, zero page errors — including the
autoplay gate driven end to end: a plugin HOLDS autoplay, the song loads but does not start, the
RELEASE fires it, and a stale release is a no-op. That is the exact machinery that was throwing.

node 1045, pytest 2425, ESLint 0 (no-cycle clean), host contract 2/2, Codex 0.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-07-12 14:22:19 +02:00

111 lines
4.7 KiB
JavaScript

// Verify closeCurrentSong() exits via origin-aware showScreen without
// restart, seek, playSong reload, or direct audio mutation.
//
// Same isolation strategy as song_restart.test.js — extract the function
// from app.js by brace-matching and run it in a vm sandbox.
const { test } = require('node:test');
const assert = require('node:assert/strict');
const fs = require('node:fs');
const path = require('node:path');
const vm = require('node:vm');
const { extractFunction } = require('./test_utils');
// R3d: closeCurrentSong (and showScreen and playSong, the mutual recursion they form) moved to
// static/js/session.js. Bodies unchanged — only the file. The WINDOW CONTRACT stays in app.js,
// which is the whole point of it: app.js is the only place that publishes names for the markup's
// onclick= handlers to resolve against.
const SESSION_JS = path.join(__dirname, '..', '..', 'static', 'js', 'session.js');
const APP_JS = path.join(__dirname, '..', '..', 'static', 'app.js');
function buildSandbox({ playerOriginScreen = 'home' } = {}) {
const sandbox = {
_playerOriginScreen: playerOriginScreen,
__showScreenCalls: [],
__restartCalls: 0,
__seekCalls: 0,
__playSongCalls: 0,
__clearLoopCalls: 0,
__audioCurrentTimeSets: [],
audio: {
_t: 42,
get currentTime() { return sandbox.audio._t; },
set currentTime(v) { sandbox.__audioCurrentTimeSets.push(v); sandbox.audio._t = v; },
},
};
vm.createContext(sandbox);
return sandbox;
}
function loadClose(sandbox, src) {
const closeSrc = extractFunction(src, 'function closeCurrentSong(');
const code = `
var _playerOriginScreen = ${JSON.stringify(sandbox._playerOriginScreen)};
globalThis.__showScreenCalls = [];
globalThis.__restartCalls = 0;
globalThis.__seekCalls = 0;
globalThis.__playSongCalls = 0;
globalThis.__clearLoopCalls = 0;
globalThis.__queueClearCalls = 0;
globalThis.__audioCurrentTimeSets = [];
// closeCurrentSong abandons any play-queue before leaving the player.
var window = { feedBack: { playQueue: { clear() { globalThis.__queueClearCalls++; } } } };
var audio = {
_t: 42,
get currentTime() { return this._t; },
set currentTime(v) { globalThis.__audioCurrentTimeSets.push(v); this._t = v; }
};
function showScreen(id) {
globalThis.__showScreenCalls.push(id);
return Promise.resolve();
}
function restartCurrentSong() { globalThis.__restartCalls++; }
async function _audioSeek() { globalThis.__seekCalls++; }
function playSong() { globalThis.__playSongCalls++; }
function clearLoop() { globalThis.__clearLoopCalls++; }
${closeSrc}
globalThis.__closeCurrentSong = closeCurrentSong;
`;
vm.runInContext(code, sandbox);
}
test('closeCurrentSong is exported on window and window.feedBack', () => {
const src = fs.readFileSync(APP_JS, 'utf8'); // the contract lives in app.js
assert.match(src, /window\.closeCurrentSong\s*=\s*closeCurrentSong/);
assert.match(src, /window\.feedBack\.closeCurrentSong\s*=\s*closeCurrentSong/);
});
test('closeCurrentSong uses _playerOriginScreen when set', async () => {
const src = fs.readFileSync(SESSION_JS, 'utf8');
const sandbox = buildSandbox({ playerOriginScreen: 'favorites' });
loadClose(sandbox, src);
await sandbox.__closeCurrentSong();
assert.equal(sandbox.__showScreenCalls.length, 1);
assert.equal(sandbox.__showScreenCalls[0], 'favorites');
assert.equal(sandbox.__queueClearCalls, 1, 'a real close abandons the play-queue');
assert.equal(sandbox.__restartCalls, 0);
assert.equal(sandbox.__seekCalls, 0);
assert.equal(sandbox.__playSongCalls, 0);
assert.equal(sandbox.__clearLoopCalls, 0);
assert.equal(sandbox.__audioCurrentTimeSets.length, 0);
});
test('closeCurrentSong falls back to home when origin missing', async () => {
const src = fs.readFileSync(SESSION_JS, 'utf8');
const sandbox = buildSandbox({ playerOriginScreen: null });
loadClose(sandbox, src);
await sandbox.__closeCurrentSong();
assert.equal(sandbox.__showScreenCalls.length, 1);
assert.equal(sandbox.__showScreenCalls[0], 'home');
});
test('closeCurrentSong falls back to home when origin is empty string', async () => {
const src = fs.readFileSync(SESSION_JS, 'utf8');
const sandbox = buildSandbox({ playerOriginScreen: '' });
loadClose(sandbox, src);
await sandbox.__closeCurrentSong();
assert.equal(sandbox.__showScreenCalls.length, 1);
assert.equal(sandbox.__showScreenCalls[0], 'home');
});