feat(react): add preact upstream tests for E2E pipeline verification

.gitmodules

@@ -0,0 +1,4 @@
+[submodule "packages/react/preact-upstream-tests/preact"]
+	path = packages/react/preact-upstream-tests/preact
+	url = https://github.com/hzy/preact.git
+	branch = lynx/v10.24.x

.typos.toml

@@ -15,6 +15,8 @@ extend-exclude = [
   "packages/web-platform/web-tests/tests/react.spec.ts",
   "packages/web-platform/web-tests/tests/react/basic-element-x-overlay-ng-playground-test/index.jsx",
   "packages/web-platform/offscreen-document/src/webworker/OffscreenCSSStyleDeclaration.ts",
+  # Upstream Preact submodule — do not spell-check third-party content
+  "packages/react/preact-upstream-tests/preact/**",
 ]
 
 [default]
@@ -31,3 +33,5 @@ nd = "nd"
 bui = "bui"
 ba = "ba"
 alog = "alog"
+# "apppend" is an intentional typo in an upstream Preact test name that we mirror in our skiplist
+apppend = "apppend"

eslint.config.js

@@ -98,6 +98,7 @@ export default tseslint.config(
       // testing-library
       'packages/testing-library/**',
       'packages/react/testing-library/**',
+      'packages/react/preact-upstream-tests/**',
 
       // gesture-runtime-testing
       'packages/lynx/gesture-runtime/__test__/**',

packages/react/preact-upstream-tests/.github/skiplist.instructions.md

@@ -0,0 +1,8 @@
+---
+applyTo: "{skiplist.json,vitest.shared.ts,README.md,package.json}"
+---
+
+When updating skiplist categories, always run each selected group in both projects (`preact-upstream` and `preact-upstream-compiled`) with `SKIPLIST_ONLY=<category>:<index>` before moving entries.
+Keep mode orthogonality explicit: shared failures stay in `skip_list`/`permanent_skip_list`, no-compile-only failures go to `nocompile_skip_list`, compiled-only failures go to `compiler_skip_list`.
+Because skip matching is title-based, check for duplicate test titles across files before removing an entry; a single title may map to multiple test cases with different outcomes.
+In README positioning and run-order guidance, treat compiled mode as the primary product-path confidence signal and describe no-compile mode as a runtime baseline/regression-isolation tool.

packages/react/preact-upstream-tests/package.json

@@ -0,0 +1,25 @@
+{
+  "name": "@lynx-js/preact-upstream-tests",
+  "version": "0.0.0",
+  "private": true,
+  "scripts": {
+    "preact:init": "cd ../../.. && git submodule update --init packages/react/preact-upstream-tests/preact",
+    "preact:status": "cd ../../.. && git submodule status packages/react/preact-upstream-tests/preact",
+    "preact:update": "cd ../../.. && git submodule update --remote packages/react/preact-upstream-tests/preact",
+    "test": "vitest run --workspace vitest.workspace.ts",
+    "test:compiled": "vitest run --workspace vitest.workspace.ts --project preact-upstream-compiled",
+    "test:no-compile": "vitest run --workspace vitest.workspace.ts --project preact-upstream",
+    "test:report": "node report.mjs",
+    "test:skipped": "SKIPLIST_ONLY=skip_list,nocompile_skip_list vitest run --workspace vitest.workspace.ts --project preact-upstream",
+    "test:skipped:compiled": "SKIPLIST_ONLY=skip_list,compiler_skip_list vitest run --workspace vitest.workspace.ts --project preact-upstream-compiled"
+  },
+  "devDependencies": {
+    "@lynx-js/react": "workspace:*",
+    "@lynx-js/testing-environment": "workspace:*",
+    "chai": "^5.2.0",
+    "jsdom": "^26.1.0",
+    "sinon": "^19.0.2",
+    "sinon-chai": "^4.0.0",
+    "vitest": "^3.2.4"
+  }
+}

packages/react/preact-upstream-tests/report.mjs

@@ -0,0 +1,267 @@
+#!/usr/bin/env node
+// Copyright 2026 The Lynx Authors. All rights reserved.
+// Licensed under the Apache License Version 2.0 that can be found in the
+// LICENSE file in the root directory of this source tree.
+
+/**
+ * report.mjs — pass/skip dashboard for preact-upstream-tests.
+ *
+ * Runs both vitest projects, parses per-file summaries, and prints a grouped
+ * coverage table.  Progress goes to stderr; the table goes to stdout so it can
+ * be piped / redirected freely.
+ *
+ * Usage:
+ *   pnpm test:report
+ *   pnpm test:report > report.txt
+ */
+
+import { spawnSync } from 'node:child_process';
+import { readFileSync } from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+
+// ── Groupings (order matters — first match wins) ──────────────────────────────
+const GROUPS = [
+  {
+    label: 'Core Reconciliation',
+    match: f => /\/(?:render|components|fragments|keys)\.test\.js$/.test(f),
+  },
+  {
+    label: 'Lifecycle Methods',
+    match: f => f.includes('/lifecycles/'),
+  },
+  {
+    label: 'Hooks',
+    match: f => f.includes('/hooks/test/browser/'),
+  },
+  {
+    label: 'API & Utilities',
+    match: () => true, // catch-all
+  },
+];
+
+// Files excluded from the vitest run (not counted in dashboard totals)
+const EXCLUDED = [
+  {
+    file: 'getDomSibling.test.js',
+    tests: 18,
+    category: 'test_methodology',
+    reason: 'Preact internals: _children VNode attachment',
+  },
+  { file: 'refs.test.js', tests: 26, category: 'dual_thread', reason: 'BSI refs ≠ DOM nodes (deferred)' },
+  {
+    file: 'replaceNode.test.js',
+    tests: 11,
+    category: 'test_methodology',
+    reason: 'SSR replaceNode / pre-populated DOM',
+  },
+];
+
+// Skiplist (with category tags) — used for attribution
+const skiplist = JSON.parse(readFileSync(path.resolve(__dirname, 'skiplist.json'), 'utf-8'));
+
+const CATEGORY_LABELS = {
+  lynx_not_web: 'Lynx ≠ Web',
+  dual_thread: 'Dual-thread / IPC',
+  test_methodology: 'Test methodology',
+};
+
+// ── Run one vitest project and return per-file stats ──────────────────────────
+function runProject(project) {
+  process.stderr.write(`  ${project.padEnd(32)} …`);
+  const r = spawnSync(
+    'npx',
+    ['vitest', 'run', '--workspace', 'vitest.workspace.ts', '--project', project],
+    { cwd: __dirname, encoding: 'utf-8', maxBuffer: 16 * 1024 * 1024 },
+  );
+  const output = (r.stdout ?? '') + (r.stderr ?? '');
+  const stats = parse(output);
+  const total = Object.values(stats).reduce((a, v) => a + v.total, 0);
+  const pass = Object.values(stats).reduce((a, v) => a + v.pass, 0);
+  process.stderr.write(` done  (${pass}/${total} pass)\n`);
+  return stats;
+}
+
+// ── Parse vitest verbose output into { file → {total, pass, skip} } ──────────
+function parse(raw) {
+  // Strip ANSI colour codes first
+  // eslint-disable-next-line no-control-regex
+  const clean = raw.replace(/\u001b\[[0-9;]*m/g, '');
+
+  // Matches lines like:
+  //   ✓ |project| preact/…/file.test.js (12 tests | 4 skipped) 30ms
+  //   ↓ |project| preact/…/file.test.js (11 tests | 11 skipped)
+  //   ✓ |project| preact/…/file.test.js (1 test) 6ms
+  const re = /\|[^|]+\|\s+(preact[^\s(]+\.test\.js)\s+\((\d+) tests?(?:\s*\|\s*(\d+) skipped)?\)/g;
+  const stats = {};
+  for (const m of clean.matchAll(re)) {
+    const file = m[1].trim();
+    const total = +m[2];
+    const skip = m[3] ? +m[3] : 0;
+    stats[file] = { total, skip, pass: total - skip };
+  }
+  return stats;
+}
+
+// ── Formatting helpers ────────────────────────────────────────────────────────
+const groupOf = f => GROUPS.find(g => g.match(f));
+const sum = (obj, k) => Object.values(obj).reduce((a, v) => a + v[k], 0);
+const pct = (n, d) => d ? `${Math.round(n * 100 / d)}%` : '—';
+const lp = (s, n) => String(s).padStart(n);
+const rp = (s, n) => String(s).padEnd(n);
+const shortName = f =>
+  f
+    .replace('preact/hooks/test/browser/', 'hooks/')
+    .replace('preact/test/browser/lifecycles/', 'lifecycles/')
+    .replace('preact/test/browser/', '');
+
+const out = (...a) => process.stdout.write(a.join('') + '\n');
+
+// ── Collect data ──────────────────────────────────────────────────────────────
+process.stderr.write('\nCollecting results:\n');
+const nc = runProject('preact-upstream');
+const co = runProject('preact-upstream-compiled');
+const files = [...new Set([...Object.keys(nc), ...Object.keys(co)])].sort();
+process.stderr.write('\n');
+
+// ── Overall totals ────────────────────────────────────────────────────────────
+const ncT = sum(nc, 'total'), ncP = sum(nc, 'pass'), ncS = sum(nc, 'skip');
+const coT = sum(co, 'total'), coP = sum(co, 'pass'), coS = sum(co, 'skip');
+const exTests = EXCLUDED.reduce((a, e) => a + e.tests, 0);
+
+const LINE = '─'.repeat(78);
+out(LINE);
+out('  Preact Upstream Tests — Coverage Dashboard');
+out(LINE);
+out(`  Excluded (not counted): ${EXCLUDED.map(e => `${e.file} (${e.tests})`).join(', ')} = ${exTests}×2 test cases`);
+out();
+
+out('OVERALL');
+out(`  ${''.padEnd(22)}  ${'no-compile'.padEnd(20)}  compiled`);
+out(`  ${rp('Total', 22)}  ${lp(ncT, 20)}  ${coT}`);
+out(`  ${rp('Pass', 22)}  ${rp(`${ncP}  (${pct(ncP, ncT)})`, 20)}  ${coP}  (${pct(coP, coT)})`);
+out(`  ${rp('Skip', 22)}  ${rp(`${ncS}  (${pct(ncS, ncT)})`, 20)}  ${coS}  (${pct(coS, coT)})`);
+out();
+
+// ── By group ──────────────────────────────────────────────────────────────────
+out(`  ${rp('GROUP', 22)}  ${rp('total', 6)}  ${rp('no-compile  pass/skip/%', 26)}  compiled  pass/skip/%`);
+out('  ' + '─'.repeat(74));
+
+for (const { label } of GROUPS) {
+  const gf = files.filter(f => groupOf(f)?.label === label);
+  if (gf.length === 0) continue;
+
+  const gt = gf.reduce((a, f) => a + (nc[f]?.total ?? co[f]?.total ?? 0), 0);
+  const ncp = gf.reduce((a, f) => a + (nc[f]?.pass ?? 0), 0);
+  const ncs = gf.reduce((a, f) => a + (nc[f]?.skip ?? 0), 0);
+  const cop = gf.reduce((a, f) => a + (co[f]?.pass ?? 0), 0);
+  const cos = gf.reduce((a, f) => a + (co[f]?.skip ?? 0), 0);
+
+  out(
+    `  ${rp(label, 22)}  ${lp(gt, 6)}  `
+      + `${rp(`${ncp}/${ncs}  (${pct(ncp, gt)})`, 26)}  `
+      + `${cop}/${cos}  (${pct(cop, gt)})`,
+  );
+}
+out();
+
+// ── Per-file detail ───────────────────────────────────────────────────────────
+out('PER FILE  (pass/skip/%)');
+out('  ' + '─'.repeat(74));
+
+for (const { label } of GROUPS) {
+  const gf = files.filter(f => groupOf(f)?.label === label).sort();
+  if (gf.length === 0) continue;
+  out(`\n  ── ${label}`);
+  for (const file of gf) {
+    const ns = nc[file] ?? { pass: 0, skip: 0, total: 0 };
+    const cs = co[file] ?? { pass: 0, skip: 0, total: 0 };
+    const tot = ns.total || cs.total;
+    const ncStr = `${lp(ns.pass, 3)}/${lp(ns.skip, 3)}  ${lp(pct(ns.pass, tot), 4)}`;
+    const coStr = `${lp(cs.pass, 3)}/${lp(cs.skip, 3)}  ${lp(pct(cs.pass, tot), 4)}`;
+    out(`  ${rp(shortName(file), 42)}  nc: ${ncStr}   co: ${coStr}`);
+  }
+}
+out();
+
+// ── Excluded files ────────────────────────────────────────────────────────────
+out('EXCLUDED FILES  (vitest exclude — not reflected above)');
+out('  ' + '─'.repeat(74));
+for (const { file, tests, category, reason } of EXCLUDED) {
+  out(`  ${rp(file, 32)}  ${lp(tests, 2)} tests/mode  [${CATEGORY_LABELS[category]}]  ${reason}`);
+}
+out(`\n  Total: ${exTests} tests × 2 modes = ${exTests * 2} test cases`);
+out();
+
+// ── Skip attribution ──────────────────────────────────────────────────────────
+// For named entries: count test names × mode factor (1 per mode the list applies to).
+// For unsupported_features: all lynx_not_web, inferred as actual_skip − named_skip.
+// Excluded files are added separately using their own category tags.
+
+function countByCat(entries, factor = 1) {
+  const acc = {};
+  for (const entry of (entries ?? [])) {
+    const cat = entry.category;
+    acc[cat] = (acc[cat] ?? 0) + entry.tests.length * factor;
+  }
+  return acc;
+}
+
+function mergeCounts(...maps) {
+  const out = {};
+  for (const m of maps) for (const [k, v] of Object.entries(m)) out[k] = (out[k] ?? 0) + v;
+  return out;
+}
+
+// Named skips per mode (each test name counted once per mode the list applies to)
+const ncNamedCats = mergeCounts(
+  countByCat(skiplist.skip_list),
+  countByCat(skiplist.permanent_skip_list),
+  countByCat(skiplist.nocompile_skip_list),
+);
+const coNamedCats = mergeCounts(
+  countByCat(skiplist.skip_list),
+  countByCat(skiplist.permanent_skip_list),
+  countByCat(skiplist.compiler_skip_list),
+);
+
+// unsupported_features contribution = actual skip − named skips (all lynx_not_web)
+const ncNamedTotal = Object.values(ncNamedCats).reduce((a, v) => a + v, 0);
+const coNamedTotal = Object.values(coNamedCats).reduce((a, v) => a + v, 0);
+ncNamedCats.lynx_not_web = (ncNamedCats.lynx_not_web ?? 0) + (ncS - ncNamedTotal);
+coNamedCats.lynx_not_web = (coNamedCats.lynx_not_web ?? 0) + (coS - coNamedTotal);
+
+// Add excluded files
+for (const { tests, category } of EXCLUDED) {
+  ncNamedCats[category] = (ncNamedCats[category] ?? 0) + tests;
+  coNamedCats[category] = (coNamedCats[category] ?? 0) + tests;
+}
+
+const ncGrand = ncS + exTests;
+const coGrand = coS + exTests;
+
+out('SKIP ATTRIBUTION  (skipped + excluded, per mode)');
+out(`  Note: unsupported_features counts inferred (actual skip − named skip), all Lynx ≠ Web`);
+out('  ' + '─'.repeat(74));
+out(`  ${rp('Category', 22)}  ${rp('no-compile', 16)}  ${rp('compiled', 16)}  combined`);
+out('  ' + '─'.repeat(74));
+
+for (const [cat, label] of Object.entries(CATEGORY_LABELS)) {
+  const nc_ = ncNamedCats[cat] ?? 0;
+  const co_ = coNamedCats[cat] ?? 0;
+  const total_ = nc_ + co_;
+  out(
+    `  ${rp(label, 22)}  `
+      + `${rp(`${nc_}  (${pct(nc_, ncGrand)})`, 16)}  `
+      + `${rp(`${co_}  (${pct(co_, coGrand)})`, 16)}  `
+      + `${total_}  (${pct(total_, ncGrand + coGrand)})`,
+  );
+}
+
+out('  ' + '─'.repeat(74));
+out(`  ${rp('Total not running', 22)}  ${rp(`${ncGrand}`, 16)}  ${rp(`${coGrand}`, 16)}  ${ncGrand + coGrand}`);
+out(`  ${rp('  of which: skipped', 22)}  ${rp(`${ncS}`, 16)}  ${rp(`${coS}`, 16)}  ${ncS + coS}`);
+out(`  ${rp('  of which: excluded', 22)}  ${rp(`${exTests}`, 16)}  ${rp(`${exTests}`, 16)}  ${exTests * 2}`);
+out(LINE);