feat(ui): support old Android in-app WebViews (es2019 + core-js + engine screen)

Old Android System WebViews (the Telegram/VK in-app browser; a real device with Google Play auto-updates the WebView, but emulators / no-Play / restricted devices stay frozen) showed a white screen. Two causes, fixed in order: - build.target es2022 shipped ?./?? verbatim, which the old engine cannot parse. Lowered to es2019 so esbuild down-levels the syntax. - The es2020+ runtime globals the bundle and its deps call (globalThis, structuredClone, Array.at, ...) are missing on those engines. A conditional core-js loader (emitPolyfills writes dist/polyfills.js, document.write'd by an index.html gate only when needed) covers them; modern engines download nothing, so the bundle-size budget is untouched. BigInt (the 64-bit FlatBuffers timestamp decode) and Proxy (Svelte 5 runes) cannot be polyfilled, so the effective floor is Chrome 67. Below it, a permanent ES5 boot guard in index.html shows a friendly "this device's OS or browser can't run the app" screen (with the web-version link inside a Mini App) and a "Diagnostic information" view with a Copy button, instead of a white screen. A reactive net raises the same screen on an uncaught boot error that never signals window.__booted. Board tile glyphs used container-query units (cqw, Chrome 105+) under .cell font-size:0, so they collapsed to 0px on Chrome 74 (invisible letters); added vmin fallbacks. The unsupported-engine telemetry beacon is a separate follow-up PR.
2026-07-04 20:36:05 +00:00
parent 44117e906c
commit 4dfedd02a3
7 changed files with 280 additions and 4 deletions
@@ -2,6 +2,209 @@
 <html lang="ru">
  <head>
    <meta charset="UTF-8" />
+    <!-- Boot capability guard. Runs before the deferred ES module, in plain ES5 so it survives even
+         on an engine too old to parse the bundle. Three jobs, as early as possible:
+           1. Hard gate — if an UNPOLYFILLABLE essential is missing (BigInt for the 64-bit
+              FlatBuffers wire decode, Proxy for Svelte 5 runes) the app cannot run at all: show the
+              unsupported-engine screen (an old Android System WebView, e.g. Chromium 66, is the case
+              this guards) instead of a white screen.
+           2. Soft gate — if only polyfillable es2020+ globals are missing (globalThis,
+              structuredClone, Array.at, …) pull core-js (emitted as polyfills.js) BEFORE the module
+              runs. document.write is deliberate: the only way to inject a parser-blocking <script>
+              guaranteed to run ahead of a deferred module; its argument is a static literal, so no
+              injection surface.
+           3. Reactive net — record any uncaught error/rejection during boot; if the app has not
+              signalled window.__booted within a grace period AND an error fired, show the same
+              screen with the captured cause (covers a bundle that fails to parse, or an unforeseen
+              incompatibility). __booted is set in App.svelte once bootstrap resolves.
+         The screen has a "Diagnostic information" view (engine + feature table + reason + version)
+         with a Copy button. On a capable engine nothing here renders, so neither the bundle-size
+         budget nor the mock e2e is affected. -->
+    <script>
+      (function () {
+        'use strict';
+        var nav = navigator;
+        var ua = nav.userAgent || '';
+        var VERSION = '__BOOT_VERSION__'; // replaced at build (vite.config injectBootVersion)
+        var RU = (nav.language || '').toLowerCase().indexOf('ru') === 0;
+        var MINIAPP = /\/(?:telegram|vk)\//.test(location.pathname);
+        var WEBURL = location.protocol + '//' + location.host + '/app/';
+
+        // [label, test, Chrome version it landed in, hard?] — hard = required and unpolyfillable.
+        function has(fn) {
+          try {
+            return !!fn();
+          } catch (e) {
+            return false;
+          }
+        }
+        var probes = [
+          ['BigInt', function () { return typeof BigInt !== 'undefined'; }, 67, true],
+          ['Proxy', function () { return typeof Proxy !== 'undefined'; }, 49, true],
+          ['globalThis', function () { return typeof globalThis !== 'undefined'; }, 71, false],
+          ['structuredClone', function () { return typeof structuredClone === 'function'; }, 98, false],
+          ['Array.prototype.at', function () { return typeof [].at === 'function'; }, 92, false],
+          ['Array.prototype.findLast', function () { return typeof [].findLast === 'function'; }, 97, false],
+          ['Object.hasOwn', function () { return typeof Object.hasOwn === 'function'; }, 93, false],
+          ['Object.fromEntries', function () { return typeof Object.fromEntries === 'function'; }, 73, false],
+          ['Promise.allSettled', function () { return !!Promise.allSettled; }, 76, false],
+          ['Promise.any', function () { return !!Promise.any; }, 85, false],
+          ['WeakRef', function () { return typeof WeakRef !== 'undefined'; }, 84, false],
+          ['queueMicrotask', function () { return typeof queueMicrotask === 'function'; }, 71, false]
+        ];
+        var results = [];
+        var hardMissing = [];
+        var softMissing = false;
+        for (var i = 0; i < probes.length; i++) {
+          var ok = has(probes[i][1]);
+          results.push({ name: probes[i][0], ok: ok, chrome: probes[i][2], hard: probes[i][3] });
+          if (!ok) {
+            if (probes[i][3]) hardMissing.push(probes[i][0]);
+            else softMissing = true;
+          }
+        }
+
+        // The diagnostic report (built on demand, behind the button).
+        function diag(reason) {
+          var cm = /Chrom(?:e|ium)\/(\d+)/.exec(ua);
+          var wv = /;\s*wv\)/.test(ua) || /\bwv\b/.test(ua);
+          var out = [];
+          out.push('reason    : ' + reason);
+          out.push('app       : ' + VERSION);
+          out.push('chromium  : ' + (cm ? cm[1] : 'n/a') + (wv ? ' (Android WebView)' : ''));
+          out.push('userAgent : ' + ua);
+          out.push('url       : ' + location.href);
+          out.push('viewport  : ' + window.innerWidth + 'x' + window.innerHeight + ' @' + (window.devicePixelRatio || 1));
+          out.push('lang      : ' + (nav.language || '?') + '   online: ' + nav.onLine);
+          out.push('');
+          out.push('features:');
+          for (var k = 0; k < results.length; k++) {
+            var r = results[k];
+            out.push('  ' + (r.ok ? 'OK' : 'NO') + '  ' + r.name + '  (' + (r.hard ? 'required' : 'polyfilled') + ', Chrome ' + r.chrome + ')');
+          }
+          return out.join('\n');
+        }
+
+        function el(tag, style, text) {
+          var e = document.createElement(tag);
+          if (style) e.setAttribute('style', style);
+          if (text != null) e.appendChild(document.createTextNode(text));
+          return e;
+        }
+        function btn(bg, fg) {
+          return 'display:inline-block;margin:0 10px 10px 0;padding:11px 18px;border:0;border-radius:8px;' +
+            'font:600 15px/1 inherit;cursor:pointer;color:' + fg + ';background:' + bg + ';';
+        }
+
+        var shown = false;
+        function show(reason) {
+          if (shown) return;
+          shown = true;
+          var root = el('div', 'position:fixed;left:0;top:0;right:0;bottom:0;z-index:2147483647;overflow:auto;' +
+            '-webkit-overflow-scrolling:touch;background:#0f1115;color:#e8eaed;box-sizing:border-box;padding:24px;' +
+            'font:16px/1.5 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Arial,sans-serif;');
+          var wrap = el('div', 'max-width:520px;margin:0 auto;');
+          root.appendChild(wrap);
+
+          var msg = el('div', null);
+          msg.appendChild(el('div', 'font-size:22px;font-weight:700;margin-bottom:14px;', 'Эрудит'));
+          msg.appendChild(el('p', 'margin:0 0 14px;', RU
+            ? 'На вашей версии операционной системы или браузера приложение не сможет работать.'
+            : "This app can't run on your device's operating system or browser version."));
+          if (MINIAPP) {
+            msg.appendChild(el('p', 'margin:0 0 6px;', RU
+              ? 'Откройте веб-версию в обычном браузере (Chrome, Firefox):'
+              : 'Open the web version in a regular browser (Chrome, Firefox):'));
+            var a = el('a', 'color:#8ab4ff;word-break:break-all;', WEBURL);
+            a.setAttribute('href', WEBURL);
+            a.setAttribute('target', '_blank');
+            a.setAttribute('rel', 'noopener');
+            var lp = el('p', 'margin:0 0 18px;');
+            lp.appendChild(a);
+            msg.appendChild(lp);
+          }
+          var infoBtn = el('button', btn('#2a2f3a', '#e8eaed'), RU ? 'Диагностическая информация' : 'Diagnostic information');
+          msg.appendChild(infoBtn);
+          wrap.appendChild(msg);
+
+          var dv = el('div', 'display:none;');
+          var pre = el('pre', 'white-space:pre-wrap;word-break:break-word;background:#0b0d11;border-radius:8px;padding:12px;' +
+            'font:12.5px/1.45 ui-monospace,Menlo,Consolas,monospace;overflow:auto;', diag(reason));
+          dv.appendChild(pre);
+          var copyBtn = el('button', btn('#8ab4ff', '#0b0d11'), RU ? 'Копировать' : 'Copy');
+          var backBtn = el('button', btn('#2a2f3a', '#e8eaed'), RU ? 'Назад' : 'Back');
+          var row = el('div', 'margin-top:12px;');
+          row.appendChild(copyBtn);
+          row.appendChild(backBtn);
+          dv.appendChild(row);
+          wrap.appendChild(dv);
+
+          infoBtn.onclick = function () {
+            msg.style.display = 'none';
+            dv.style.display = 'block';
+          };
+          backBtn.onclick = function () {
+            dv.style.display = 'none';
+            msg.style.display = 'block';
+          };
+          copyBtn.onclick = function () {
+            var txt = diag(reason);
+            try {
+              if (nav.clipboard && nav.clipboard.writeText) {
+                nav.clipboard.writeText(txt);
+                copyBtn.firstChild.nodeValue = RU ? 'Скопировано' : 'Copied';
+                return;
+              }
+            } catch (e) {}
+            try {
+              var ta = document.createElement('textarea');
+              ta.value = txt;
+              ta.setAttribute('style', 'position:fixed;left:-9999px;top:0;');
+              document.body.appendChild(ta);
+              ta.select();
+              document.execCommand('copy');
+              document.body.removeChild(ta);
+              copyBtn.firstChild.nodeValue = RU ? 'Скопировано' : 'Copied';
+            } catch (e2) {
+              copyBtn.firstChild.nodeValue = RU ? 'Выделите и скопируйте текст' : 'Select and copy the text';
+            }
+          };
+
+          function mount() {
+            document.body.insertBefore(root, document.body.firstChild);
+          }
+          if (document.body) mount();
+          else document.addEventListener('DOMContentLoaded', mount);
+        }
+
+        // 1 + 2: the gate.
+        if (hardMissing.length) {
+          show((RU ? 'нет: ' : 'missing: ') + hardMissing.join(', '));
+        } else if (softMissing) {
+          document.write('<script src="polyfills.js"><\/script>');
+        }
+
+        // 3: the reactive net for an unforeseen boot failure.
+        var bootErr = null;
+        function note(m) {
+          if (!bootErr) bootErr = m;
+        }
+        window.onerror = function (m, s, l, c, e) {
+          note(String(m) + (e && e.stack ? '\n' + e.stack : s ? ' @ ' + s + ':' + l : ''));
+          return false;
+        };
+        window.addEventListener('error', function (e) {
+          if (e && e.message) note(e.message + (e.filename ? ' @ ' + e.filename + ':' + e.lineno : ''));
+        }, true);
+        window.addEventListener('unhandledrejection', function (e) {
+          var r = e && e.reason;
+          note(r && (r.stack || r.message) ? r.stack || r.message : String(r));
+        });
+        setTimeout(function () {
+          if (!window.__booted && bootErr && !shown) show((RU ? 'ошибка запуска: ' : 'boot error: ') + bootErr);
+        }, 8000);
+      })();
+    </script>
    <!-- The SPA shell is an empty client-rendered document behind the public landing — keep it
         out of search indexes (robots.txt deliberately does NOT disallow /app/, so crawlers can
         reach this tag). -->
@@ -27,6 +27,7 @@
    "@playwright/test": "^1.49.0",
    "@sveltejs/vite-plugin-svelte": "^5.0.0",
    "@types/node": "^22.10.0",
+    "core-js-bundle": "^3.49.0",
    "svelte": "^5.15.0",
    "svelte-check": "^4.1.0",
    "typescript": "^5.7.0",
@@ -36,6 +36,9 @@ importers:
      '@types/node':
        specifier: ^22.10.0
        version: 22.19.19
+      core-js-bundle:
+        specifier: ^3.49.0
+        version: 3.49.0
      svelte:
        specifier: ^5.15.0
        version: 5.56.0
@@ -508,6 +511,9 @@ packages:
    resolution: {integrity: sha512-eYm0QWBtUrBWZWG0d386OGAw16Z995PiOVo2B7bjWSbHedGl5e0ZWaq65kOGgUSNesEIDkB9ISbTg/JK9dhCZA==}
    engines: {node: '>=6'}

+  core-js-bundle@3.49.0:
+    resolution: {integrity: sha512-WXc7oOsePN3aKFOJVG5zQdi+h/Jm2W0WIPYvRc4IG3vkNcbC2w6LlSzTmnhOl6N1xmOJEzCSNieX3mwF+3zBGw==}
+
  debug@4.4.3:
    resolution: {integrity: sha512-RGwwWnwQvkVfavKVt22FGLw+xYSdzARwm0ru6DhTVA3umU5hZc28V3kO4stgYryrTlLpuvgI9GiijltAjNbcqA==}
    engines: {node: '>=6.0'}
@@ -1132,6 +1138,8 @@ snapshots:

  clsx@2.1.1: {}

+  core-js-bundle@3.49.0: {}
+
  debug@4.4.3:
    dependencies:
      ms: 2.1.3
@@ -1,4 +1,8 @@
 # pnpm 11 records build-script approval here. esbuild's postinstall materialises
 # its CLI shim; the platform binary itself ships as an optional dependency.
+# core-js-bundle ships a prebuilt minified.js (we only read that file at build time,
+# via vite.config emitPolyfills) and its install script is just a funding banner, so
+# it is denied — nothing to build.
 allowBuilds:
+  core-js-bundle: false
  esbuild: true
@@ -26,7 +26,12 @@
  import TelegramLaunchError from './screens/TelegramLaunchError.svelte';

  onMount(() => {
-    void bootstrap();
+    // Tell the index.html boot guard that startup completed, so its reactive net does not raise the
+    // unsupported-engine screen on a healthy boot — it only fires when an uncaught error occurred
+    // AND this flag never sets (a bundle that failed to parse, or an unforeseen incompatibility).
+    void bootstrap().then(() => {
+      (window as unknown as { __booted?: boolean }).__booted = true;
+    });
  });

  // The lobby is the cold-start landing (an empty hash and Telegram launch params both parse
@@ -479,6 +479,11 @@
    position: absolute;
    top: 5%;
    left: 8%;
+    /* Chrome < 105 has no container-query units: a dropped `cqw` would inherit the .cell
+       `font-size: 0` and the glyph would vanish. Fall back to a viewport-relative size that tracks
+       the board (≈ the viewport-fitted query container) and the zoom (--z), so old Android System
+       WebViews still draw the tile glyphs. Chrome 105+ takes the exact `cqw` line below. */
+    font-size: calc(4.2vmin * var(--z, 1));
    font-size: 4.2cqw;
    font-weight: 700;
    line-height: 1;
@@ -487,12 +492,14 @@
    position: absolute;
    right: 5%;
    bottom: 3%;
+    font-size: calc(2.4vmin * var(--z, 1)); /* cqw fallback for Chrome < 105 — see .letter */
    font-size: 2.4cqw;
    font-weight: 600;
  }
  /* A placed Erudit blank ("звёздочка") shows its star where the (absent) point value sits,
     its ink centred on the same line as a neighbouring tile's value digit. */
  .blankmark {
+    font-size: calc(2.8vmin * var(--z, 1)); /* cqw fallback for Chrome < 105 — see .letter */
    font-size: 2.8cqw;
    bottom: 0;
  }
@@ -501,6 +508,7 @@
    inset: 0;
    display: grid;
    place-items: center;
+    font-size: calc(3.6vmin * var(--z, 1)); /* cqw fallback for Chrome < 105 — see .letter */
    font-size: 3.6cqw;
    opacity: 0.7;
  }
@@ -509,6 +517,7 @@
    inset: 0;
    display: grid;
    place-items: center;
+    font-size: calc(2.7vmin * var(--z, 1)); /* cqw fallback for Chrome < 105 — see .letter */
    font-size: 2.7cqw;
    font-weight: 600;
    opacity: 0.9;
@@ -526,10 +535,12 @@
    padding: 0 1px;
  }
  .bt {
+    font-size: calc(1.7vmin * var(--z, 1)); /* cqw fallback for Chrome < 105 — see .letter */
    font-size: 1.7cqw;
    font-weight: 600;
  }
  .bb {
+    font-size: calc(1.9vmin * var(--z, 1)); /* cqw fallback for Chrome < 105 — see .letter */
    font-size: 1.9cqw;
    font-weight: 700;
    white-space: nowrap;
@@ -1,7 +1,42 @@
+import { readFileSync } from 'node:fs';
 import { resolve } from 'node:path';
-import { defineConfig } from 'vite';
+import { defineConfig, type Plugin } from 'vite';
 import { svelte } from '@sveltejs/vite-plugin-svelte';

+/**
+ * injectBootVersion stamps the app version into index.html's boot-capability guard, replacing its
+ * __BOOT_VERSION__ placeholder with the same VITE_APP_VERSION build-arg that feeds __APP_VERSION__.
+ * The guard runs before the bundle, so it cannot read the bundle's version; this lets its on-demand
+ * diagnostic report name the client version anyway. Falls back to "dev" for a local build.
+ */
+function injectBootVersion(): Plugin {
+  const version = process.env.VITE_APP_VERSION || 'dev';
+  return {
+    name: 'inject-boot-version',
+    transformIndexHtml(html) {
+      return html.replace(/__BOOT_VERSION__/g, version);
+    },
+  };
+}
+
+/**
+ * emitPolyfills writes the prebuilt core-js bundle to `dist/polyfills.js`. The index.html gate
+ * script loads it via document.write only on an old engine that lacks the es2020+ runtime APIs the
+ * app uses (globalThis, structuredClone, Array.at, …) — e.g. the Chromium 66 Android System WebView
+ * behind the Telegram/VK in-app browser — before the deferred module runs. A modern engine never
+ * requests it, so it adds nothing to that payload and stays out of the module graph the bundle-size
+ * gate measures.
+ */
+function emitPolyfills(): Plugin {
+  return {
+    name: 'emit-polyfills',
+    generateBundle() {
+      const src = readFileSync(resolve(import.meta.dirname, 'node_modules/core-js-bundle/minified.js'), 'utf8');
+      this.emitFile({ type: 'asset', fileName: 'polyfills.js', source: src });
+    },
+  };
+}
+
 // The edge Connect service is scrabble.edge.v1.Gateway; the gateway serves it over
 // h2c on :8081 by default. In dev we proxy the RPC path so the browser (which can
 // not speak h2c directly) talks to the dev server on the same origin. In `mock`
@@ -19,7 +54,9 @@ export default defineConfig(({ mode }) => ({
    // so a missing build-arg never breaks the build.
    __APP_VERSION__: JSON.stringify(process.env.VITE_APP_VERSION || 'dev'),
  },
-  plugins: [svelte()],
+  // emitPolyfills ships dist/polyfills.js (loaded only by old engines; see its docstring + the
+  // index.html boot guard). injectBootVersion stamps the app version into that guard's diagnostic.
+  plugins: [svelte(), emitPolyfills(), injectBootVersion()],
  server: {
    port: 5173,
    proxy:
@@ -33,7 +70,14 @@ export default defineConfig(({ mode }) => ({
          },
  },
  build: {
-    target: 'es2022',
+    // Down-level to es2019 so an old Android System WebView (seen: Telegram/VK in-app WebView on
+    // Chromium 66, Android 9) can parse the bundle — esbuild lowers es2020+ syntax (?., ??, private
+    // fields, static blocks, …) that Chrome 66 rejects with "Unexpected token ?", which left the SPA
+    // on a white screen. esbuild lowers syntax only, not runtime APIs — the es2020+ globals the
+    // bundle/deps call at runtime (globalThis, structuredClone, Array.at, …) are covered separately
+    // by the conditional core-js loader (emitPolyfills + the index.html gate), loaded only on an
+    // engine that actually lacks them.
+    target: 'es2019',
    // Emit sourcemaps everywhere except the production build. A shipped `.map`
    // carries full `sourcesContent` — the entire TypeScript/Svelte source — and the
    // gateway/landing images serve `dist/` verbatim, so production maps would expose