From f27d4f623ca359847c83727d271751e8df650a84 Mon Sep 17 00:00:00 2001 From: Byron Gamatos Date: Sun, 12 Jul 2026 16:05:50 +0200 Subject: [PATCH] =?UTF-8?q?fix(nav):=20the=20library=20sometimes=20showed?= =?UTF-8?q?=20the=20legacy=20screen=20=E2=80=94=20map=20'home'=20inside=20?= =?UTF-8?q?showScreen=20(#923)?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Testers: "randomly, when moving to the library from another menu option, the library shows the old interface — never when a song ends." ━━━ WHAT WAS ACTUALLY HAPPENING ━━━ #home is the PRE-V3 library screen. The v3 shell replaced it with #v3-songs, and the mapping DID exist — but only inside WRAPPERS on window.showScreen, and only for callers that go through `window`. THREE independent parties monkey-patch it, each capturing whatever happens to be there at the time: app.js publishes the raw function -> shell.js wraps it, adding the home -> v3-songs mapping -> the stems plugin wraps it AGAIN (src/main.js:1029), capturing the current value Plugins load ASYNCHRONOUSLY. The chain links up in whatever order the race settles, and any capture taken before shell.js installs — or any re-assignment after it — silently drops the mapping. Hence "randomly". AND THE INTERNAL CALLERS NEVER TOUCHED window.showScreen AT ALL. closeCurrentSong and the Esc-from-settings shortcut call the IMPORTED showScreen, which no wrapper ever sees. Reproduced in a browser: the unwrapped function with 'home' lands on the dead legacy screen EVERY time. "Never when a song ends" is the tell, and it is what identified the mechanism: closeCurrentSong resolves its target through _resolvePlayerOrigin(), which ALREADY applies this mapping. That one path was fine — which is exactly why the bug looked random rather than total. PRE-EXISTING, not a regression from the module carve: the onclick="showScreen('home')" links and the wrapper-only mapping both date to 2026-06-22. ━━━ THE FIX ━━━ The guard lives inside showScreen now: ONE place, in the function every caller routes through, instead of a chain of monkey-patches that must each remember. Wrapper order stops mattering, and the module-internal callers are covered for the first time. Verified in a browser: the raw, unwrapped showScreen('home') — which reproduced as #home — now lands on #v3-songs, and cannot be undone by any wrapper order. ━━━ AND A [P1] I INTRODUCED, WHICH CODEX CAUGHT ━━━ My first cut mapped BOTH 'home' and 'v3-home', copied straight from _resolvePlayerOrigin. That is correct THERE and wrong HERE. _resolvePlayerOrigin computes where to RETURN TO after a song, and landing on the Songs list from the dashboard is the right behaviour. But #v3-home is the v3 DASHBOARD — a real screen that the shell's Home nav, the onboarding tour and the dashboard re-render listener all target. Redirecting it would have made Home unreachable. A LEGACY ALIAS IS NOT THE SAME THING AS A RETURN TARGET. Only 'home' is mapped now, and a test pins that: re-adding 'v3-home' to the guard fails it. 4 tests, bite-tested both ways. node 1049, pytest 2425, ESLint 0, Codex 0. Co-authored-by: Claude Opus 4.8 (1M context) --- static/js/session.js | 39 +++++++++++ tests/js/show_screen_legacy_home.test.js | 85 ++++++++++++++++++++++++ 2 files changed, 124 insertions(+) create mode 100644 tests/js/show_screen_legacy_home.test.js diff --git a/static/js/session.js b/static/js/session.js index 264930c..c984fc5 100644 --- a/static/js/session.js +++ b/static/js/session.js @@ -105,6 +105,45 @@ export let _settingsOriginScreen = 'home'; // ── Screen Navigation ───────────────────────────────────────────────────── export async function showScreen(id) { + // ── 'home' is the LEGACY library screen. Always route it to the v3 Songs list. ── + // + // The v3 shell replaced #home with #v3-songs. That mapping DID exist — but only inside + // wrappers on `window.showScreen`, and only for callers that go through `window`: + // + // app.js publishes the raw fn -> shell.js wraps it (adding the mapping) + // -> the stems plugin wraps it AGAIN, capturing whatever + // happened to be there at the time + // + // Two ways that fails, and testers hit both: + // + // 1. ORDER. Three independent parties monkey-patch window.showScreen, each capturing the + // current value. Plugins load ASYNCHRONOUSLY, so the chain links up in whatever order + // the race settles — and any capture taken before shell.js installs, or any + // re-assignment after it, silently drops the mapping. + // + // 2. THE INTERNAL CALLERS NEVER TOUCHED window.showScreen AT ALL. closeCurrentSong and the + // Esc-from-settings shortcut call the IMPORTED showScreen directly, so no wrapper ever + // sees them. Verified in a browser: the unwrapped function with 'home' lands on the dead + // legacy screen every single time. + // + // Hence "randomly, when moving to the library from another menu option" — and "never when a + // song ends", because closeCurrentSong resolves its target through _resolvePlayerOrigin(), + // which already applies this mapping. + // + // So it lives HERE now: ONE guard in the function every caller routes through, rather than a + // chain of monkey-patches that must each remember. + // + // ONLY 'home'. NOT 'v3-home'. _resolvePlayerOrigin() maps BOTH — correctly, because it + // computes where to RETURN TO after a song, and coming back to the Songs list from the + // dashboard is the right behaviour. Copying that condition here was a [P1] (Codex caught it): + // #v3-home is the v3 DASHBOARD, a real screen the shell's Home nav, the onboarding tour and + // the dashboard re-render listener all target. Redirecting it would make Home unreachable. + // + // A legacy alias is not the same thing as a return target. + if (id === 'home' && document.getElementById('v3-songs')) { + id = 'v3-songs'; + } + // Capture the previous screen before changing active classes const prevScreenId = document.querySelector('.screen.active')?.id; document.querySelectorAll('.screen').forEach(s => s.classList.remove('active')); diff --git a/tests/js/show_screen_legacy_home.test.js b/tests/js/show_screen_legacy_home.test.js new file mode 100644 index 0000000..7f0a1cf --- /dev/null +++ b/tests/js/show_screen_legacy_home.test.js @@ -0,0 +1,85 @@ +// showScreen('home') must never land on the LEGACY library screen when v3 is present. +// +// Testers: "randomly, when moving to the library from another menu option, the library shows the +// old interface — never when a song ends." +// +// #home is the pre-v3 library screen. The v3 shell replaced it with #v3-songs, and the mapping +// DID exist — but only inside wrappers on `window.showScreen`, which fail two ways: +// +// 1. ORDER. THREE independent parties monkey-patch window.showScreen, each capturing whatever +// is there at the time: app.js publishes the raw function, shell.js wraps it to add the +// mapping, and the stems plugin wraps it again. Plugins load ASYNCHRONOUSLY, so the chain +// links up in whatever order the race settles. A capture taken before shell.js installs — +// or any re-assignment after it — silently drops the mapping. Hence "randomly". +// +// 2. THE INTERNAL CALLERS BYPASS window.showScreen ENTIRELY. closeCurrentSong and the +// Esc-from-settings shortcut call the IMPORTED showScreen, which no wrapper ever sees. +// Verified in a browser: the unwrapped function with 'home' lands on #home, always. +// +// "Never when a song ends" is the tell: closeCurrentSong resolves its target through +// _resolvePlayerOrigin(), which already applied the mapping — so that one path was fine. +// +// The guard now lives inside showScreen itself: one place every caller routes through. + +const { test } = require('node:test'); +const assert = require('node:assert/strict'); +const fs = require('node:fs'); +const path = require('node:path'); + +const SESSION_JS = path.join(__dirname, '..', '..', 'static', 'js', 'session.js'); +const src = () => fs.readFileSync(SESSION_JS, 'utf8'); + +function bodyOf(name) { + const s = src(); + const at = s.indexOf(`export async function ${name}(`); + assert.notEqual(at, -1, `${name} not found`); + let depth = 0; + for (let i = s.indexOf('{', at); i < s.length; i++) { + if (s[i] === '{') depth++; + else if (s[i] === '}' && --depth === 0) return s.slice(at, i + 1); + } + throw new Error('unbalanced'); +} + +test('showScreen maps the legacy #home library to #v3-songs', () => { + const fn = bodyOf('showScreen'); + assert.match( + fn, + /id\s*===\s*'home'[\s\S]{0,80}getElementById\('v3-songs'\)[\s\S]{0,60}id\s*=\s*'v3-songs'/, + "showScreen must route 'home' to 'v3-songs' ITSELF — relying on a wrapper over " + + 'window.showScreen loses the mapping whenever a plugin wraps it first, and misses the ' + + 'module-internal callers (closeCurrentSong, Esc-from-settings) altogether', + ); +}); + +test('the guard runs BEFORE the screen is activated', () => { + const fn = bodyOf('showScreen'); + const guard = fn.search(/id\s*=\s*'v3-songs'/); + const activate = fn.indexOf('classList.add(\'active\')'); + assert.ok(guard !== -1 && activate !== -1); + assert.ok(guard < activate, + 'the mapping must be applied before the screen is activated, or #home is shown first'); +}); + +test('the guard is conditional on v3 actually being present', () => { + const fn = bodyOf('showScreen'); + assert.match(fn, /getElementById\('v3-songs'\)/, + 'the mapping must check #v3-songs exists — without it there is nowhere to route to'); +}); + +test('it does NOT redirect v3-home — the dashboard is a real screen', () => { + // Codex [P1] on the first cut. _resolvePlayerOrigin() maps BOTH 'home' and 'v3-home' — + // correctly, because it computes where to RETURN TO after a song, and landing on the Songs + // list from the dashboard is right. Copying that condition into showScreen is NOT: #v3-home + // is the v3 DASHBOARD, which the shell's Home nav, the onboarding tour and the dashboard + // re-render listener all target. Redirecting it makes Home unreachable. + // + // A legacy alias is not the same thing as a return target. + const fn = bodyOf('showScreen'); + // the condition, i.e. everything between `if (` and the `{` that opens `id = 'v3-songs'` + const m = fn.match(/if \(([\s\S]*?)\)\s*\{\s*id = 'v3-songs';/); + assert.ok(m, 'the legacy-home guard was not found'); + assert.doesNotMatch(m[1], /v3-home/, + "showScreen must NOT redirect 'v3-home' — that is the dashboard, not the legacy library"); + assert.match(m[1], /id === 'home'/, "it must still redirect the legacy 'home'"); +});