CI: three test shards per OS from measured weights; Chrome tests share a browser

.github/workflows/ci.yml

@@ -67,16 +67,19 @@ jobs:
       - run: git diff --check
 
   tests:
-    name: Tests (${{ matrix.os }}, ${{ matrix.shard }}/2)
+    name: Tests (${{ matrix.os }}, ${{ matrix.shard }}/3)
     needs: changes
     if: needs.changes.outputs.code == 'true'
     runs-on: ${{ matrix.os }}
-    timeout-minutes: 10
+    # Three shards per OS: test steps measured 4.9-6.6 minutes and whole jobs 6-7.8 minutes on 2026-10-22 (two shards had
+    # reached 8-10 minutes against a 10-minute cap). The cap is about 1.5x the slowest job, so slow macOS runners pass and a
+    # hang still fails the job; every test keeps its own 120 s timeout.
+    timeout-minutes: 12
     strategy:
       fail-fast: false
       matrix:
         os: [macos-latest, ubuntu-24.04]
-        shard: [1, 2]
+        shard: [1, 2, 3]
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
@@ -101,7 +104,7 @@ jobs:
           echo "NMSH_TEST_MERMAID=$dir/package" >> "$GITHUB_ENV"
       # Built-launcher tests must execute rather than silently skip on fresh runners.
       - run: npm run build
-      - run: npm test -- --shard=${{ matrix.shard }}/2 --test-timeout=120000
+      - run: npm test -- --shard=${{ matrix.shard }}/3 --test-timeout=120000
       - name: Process leak check
         if: always()
         run: bash scripts/check-process-leaks.sh

docs/development-verification.md

@@ -22,13 +22,16 @@ Local commands reuse node_modules. Clean CI/release environments use
 
 ## Canonical suite and sharding
 
-The only shard interface is `npm test -- --shard=1/2` (or `2/2`). No arguments
+The only shard interface is `npm test -- --shard=<index>/<count>` (CI uses `1/3`, `2/3`, `3/3`). No arguments
 still runs every recursively discovered `tests/**/*.test.ts` file. File selection
 lives in `scripts/test-selection.mjs`; its tests verify deterministic assignment,
 exact union, no overlap, invalid-input rejection, and curated-list existence.
 Runtime files are partitioned as whole files by deterministic greedy scheduling.
 Rounded measured weights for slow files balance PTY work; ordinary/new files
-default to one. Reprofile weights only when actual shard imbalance warrants it. `suggestionRanking.test.ts` runs
+default to one. Reprofile weights only when actual shard imbalance warrants it: the per-test durations in the
+CI logs, attributed to their files, are the source (last done 2026-10-22, when unweighted browser and live files had pushed
+shards to 8–10 minutes of a 10-minute cap). Tests that drive a real Chromium share one browser per file where they test
+pages rather than the browser's own lifecycle (`sharedLab()` in `tests/support/browserFixtures.ts`). `suggestionRanking.test.ts` runs
 separately after runtime files, only in shard one, preserving uncontested latency
 measurement. New files automatically enter the canonical suite and a shard.
 
@@ -40,8 +43,8 @@ session scenarios run fully on Node 26 on both macOS and Ubuntu.
 
 ## CI gates
 
-Code PRs run quality on Ubuntu/Node 26, two macOS/Node 26 shards, two Ubuntu/Node
-26 shards, and curated Ubuntu/Node 22 compatibility. Each shard builds because
+Code PRs run quality on Ubuntu/Node 26, three macOS/Node 26 shards, three Ubuntu/Node
+26 shards (12-minute cap each, about 1.5 times the slowest measured job, so a hang still fails), and curated Ubuntu/Node 22 compatibility. Each shard builds because
 built-launcher tests otherwise skip on a clean checkout. Each integration shard
 and smoke job checks helper-process leaks, including after a test failure.
 Existing hard latency assertions remain in the canonical tests.

scripts/test-selection.mjs

@@ -18,36 +18,80 @@ const suites = {
   fedora: ['linuxPlatform', 'tools', 'update', 'hostProfiles', 'portabilityUninstall'],
 };
 
-// Rounded seconds from the macOS Node 26 canonical baseline (2026-10-04).
+// Rounded seconds: the slower of the macOS and Ubuntu Node 26 CI shards (run 39756506927, 2026-10-22); files not
+// measured there keep their 2026-10-04 macOS baseline. The two Chrome files are estimates after they began sharing one
+// browser per file.
 // Only slow files need weights; new/ordinary files default to one. Greedy
 // whole-file scheduling avoids clustering the costly PTY files in one shard.
 const runtimeWeights = {
-  "bundledCatalog.test.ts": 5,
-  "compatibilityHarness.test.ts": 28,
-  "commandQueueLive.test.ts": 93,
-  "copySelectionLive.test.ts": 13,
-  "configuredCompletion.test.ts": 6,
-  "ctrlZJobControl.test.ts": 12,
-  "detachedOutput.test.ts": 22,
+  "activityStyleLive.test.ts": 16,
+  "ansiLiveRegion.test.ts": 15,
+  "arcadeAll.test.ts": 8,
+  "arcadeBackgroundLive.test.ts": 52,
+  "arcadeDashGame.test.ts": 26,
+  "arcadeDashPhysics.test.ts": 26,
+  "arcadePinball.test.ts": 20,
+  "arcadeQueensLogic.test.ts": 15,
+  "arcadeSudokuLogic.test.ts": 6,
+  "backgroundSupervisor.test.ts": 11,
+  "browserEngineChrome.test.ts": 50,
+  "browserPanel.test.ts": 6,
+  "bundledCatalog.test.ts": 11,
+  "chromaV2.test.ts": 6,
+  "clipsLive.test.ts": 6,
+  "commandQueueLive.test.ts": 97,
+  "compareOutputLive.test.ts": 10,
+  "compatibilityHarness.test.ts": 47,
+  "configuredCompletion.test.ts": 13,
+  "contextEngine.test.ts": 13,
+  "contextHostileWorkspace.test.ts": 9,
+  "copyExactLive.test.ts": 7,
+  "copyPayload.test.ts": 5,
+  "copyReportLive.test.ts": 5,
+  "copySelectionLive.test.ts": 51,
+  "ctrlZJobControl.test.ts": 24,
+  "detachedOutput.test.ts": 38,
+  "diagramsChrome.test.ts": 25,
+  "flowComposer.test.ts": 8,
   "fullChromaQa.test.ts": 5,
-  "hostProfiles.test.ts": 10,
-  "inputAwarenessLive.test.ts": 59,
-  "interactiveCli.test.ts": 14,
-  "liveHardening.test.ts": 45,
-  "liveStatus.test.ts": 5,
-  "muxInterop.test.ts": 31,
-  "nativeCaptureLifecycle.test.ts": 6,
-  "sessionLifecycle.test.ts": 28,
-  "sessionPresets.test.ts": 20,
+  "fullscreenFailure.test.ts": 8,
+  "fullscreenResizeSampling.test.ts": 10,
+  "historyReuseLive.test.ts": 11,
+  "hostProfiles.test.ts": 18,
+  "hybrid.test.ts": 6,
+  "inputAwarenessLive.test.ts": 52,
+  "inputOwnershipLive.test.ts": 46,
+  "interactiveCli.test.ts": 37,
+  "keepAwakeForeground.test.ts": 8,
+  "liveHardening.test.ts": 88,
+  "liveStatus.test.ts": 10,
+  "moduleDiagnosticsLive.test.ts": 7,
+  "muxInterop.test.ts": 47,
+  "nativeCaptureLifecycle.test.ts": 8,
+  "outputReferencesLive.test.ts": 7,
   "pasteBatchLive.test.ts": 21,
+  "pinsLive.test.ts": 7,
   "queueConditionsLive.test.ts": 24,
+  "queuePreviewLive.test.ts": 33,
+  "queueSummaryLive.test.ts": 23,
+  "sessionLifecycle.test.ts": 78,
+  "sessionPresets.test.ts": 45,
   "shellAdapters.test.ts": 35,
+  "shellIntelligence.test.ts": 22,
   "shellSwitchApp.test.ts": 23,
-  "startupBlocked.test.ts": 29,
-  "startupDiscovery.test.ts": 22,
-  "startupLaunch.test.ts": 8,
+  "startupBlocked.test.ts": 64,
+  "startupDiscovery.test.ts": 87,
+  "startupLaunch.test.ts": 10,
+  "startupLifecycle.test.ts": 7,
+  "terminalBaseline.test.ts": 9,
+  "terminalModeReconciliation.test.ts": 8,
+  "themeBridgeLive.test.ts": 5,
+  "tmpdirHygiene.test.ts": 9,
+  "toolConfig.test.ts": 6,
+  "trackLive.test.ts": 13,
   "typingAfterRead.test.ts": 17,
-  "themeBridgeLive.test.ts": 12
+  "viewerLive.test.ts": 13,
+  "worktreeMutations.test.ts": 11
 };
 
 export function discoverTestFiles() {

tests/browserEngineChrome.test.ts

@@ -1,9 +1,9 @@
-import test from 'node:test';
+import test, {after} from 'node:test';
 import assert from 'node:assert/strict';
 import fs from 'node:fs';
 import path from 'node:path';
 import type {BrowserPage, Frame} from '../src/browser/types.js';
-import {chromeSkipReason, createLab, Events, localSite, pidAlive, scratchDir, waitFor} from './support/browserFixtures.js';
+import {chromeSkipReason, createLab, disposeSharedLab, Events, localSite, pidAlive, scratchDir, sharedLab, waitFor} from './support/browserFixtures.js';
 import {createBrowserEngine} from '../src/browser/engine/index.js';
 
 /**
@@ -14,6 +14,7 @@ const skip = await chromeSkipReason();
 const view = {width: 600, height: 400, scale: 1};
 const sleep = (ms: number): Promise<void> => new Promise(resolve => setTimeout(resolve, ms));
 const settled = (page: BrowserPage, url?: string): Promise<true> => waitFor(() => (url === undefined || page.url === url) && !page.loading && true, `${url ?? 'the page'} to load`);
+after(disposeSharedLab);
 
 test('launch is lazy, uses a private profile, and shutdown leaves no process behind', {skip}, async () => {
   const lab = createLab();
@@ -93,7 +94,7 @@ test('a missing browser is reported in plain words and nothing is started', asyn
 });
 
 test('web pages load from a local server; navigation, back, forward and reload work', {skip}, async () => {
-  const lab = createLab();
+  const lab = sharedLab();
   const site = await localSite({'/a': '<title>Page A</title><p>a</p>', '/b': '<title>Page B</title><p>b</p>'});
   try {
     const page = await lab.engine.open({kind: 'web', viewport: view, url: `${site.origin}/a`});
@@ -122,7 +123,7 @@ test('web pages load from a local server; navigation, back, forward and reload w
 });
 
 test('addresses that are not http, https, file or about:blank are refused and never navigated', {skip}, async () => {
-  const lab = createLab();
+  const lab = sharedLab();
   try {
     const page = await lab.engine.open({kind: 'web', viewport: view, url: 'about:blank'});
     const events = new Events(page);
@@ -138,7 +139,7 @@ test('addresses that are not http, https, file or about:blank are refused and ne
 });
 
 test('a page that redirects or links to a refused scheme ends on about:blank with a blocked event', {skip}, async () => {
-  const lab = createLab();
+  const lab = sharedLab();
   const site = await localSite({'/': '<a id=l href="blob:nope" style="position:absolute;left:0;top:0;width:300px;height:60px;display:block">x</a><title>start</title>'});
   try {
     const page = await lab.engine.open({kind: 'web', viewport: view, url: site.origin + '/'});
@@ -158,7 +159,7 @@ test('a page that redirects or links to a refused scheme ends on about:blank wit
 const animation = '<style>@keyframes a{from{transform:translateX(0)}to{transform:translateX(300px)}}div{width:80px;height:80px;background:#d33;animation:a 1s linear infinite}</style><div></div>';
 
 test('screencast frames arrive at the viewport size, advance with a CSS animation, and a slow listener skips frames', {skip}, async () => {
-  const lab = createLab();
+  const lab = sharedLab();
   try {
     const handle = await lab.preview(animation);
     const page = await lab.engine.open({kind: 'preview', viewport: {width: 320, height: 200, scale: 1}, url: handle.url});
@@ -197,7 +198,7 @@ test('screencast frames arrive at the viewport size, advance with a CSS animatio
 });
 
 test('zoom keeps the frame size and is clamped', {skip}, async () => {
-  const lab = createLab();
+  const lab = sharedLab();
   try {
     const handle = await lab.preview('<h1>zoom</h1>');
     const page = await lab.engine.open({kind: 'preview', viewport: {width: 300, height: 200, scale: 1}, url: handle.url});
@@ -224,7 +225,7 @@ const form = `<body style="margin:0"><input id=f style="position:absolute;left:1
 <script>f.addEventListener('input',()=>{document.title='v:'+f.value});</script></body>`;
 
 test('mouse and keys reach a trusted page: typing in a field, editable events, and a click on a link', {skip}, async () => {
-  const lab = createLab();
+  const lab = sharedLab();
   try {
     const handle = await lab.preview(form, {trusted: true, files: {'next.html': '<title>next</title><p>second</p>'}});
     const page = await lab.engine.open({kind: 'preview', viewport: view, url: handle.url, scripts: true});
@@ -260,7 +261,7 @@ test('mouse and keys reach a trusted page: typing in a field, editable events, a
 });
 
 test('wheel events scroll the page', {skip}, async () => {
-  const lab = createLab();
+  const lab = sharedLab();
   try {
     const handle = await lab.preview('<body style="margin:0;height:3000px"><div style="height:3000px;background:linear-gradient(#fff,#000)"></div>');
     const page = await lab.engine.open({kind: 'preview', viewport: view, url: handle.url});
@@ -276,7 +277,7 @@ test('wheel events scroll the page', {skip}, async () => {
 });
 
 test('find works on a preview with scripts off, steps and wraps, and clears', {skip}, async () => {
-  const lab = createLab();
+  const lab = sharedLab();
   try {
     const handle = await lab.preview('<p>Needle one</p><p>nothing</p><p>second needle</p><script>document.title="scripts ran"</script><p style="display:none">needle hidden</p><p>NEEDLE last</p>');
     const page = await lab.engine.open({kind: 'preview', viewport: view, url: handle.url});
@@ -299,7 +300,7 @@ test('find works on a preview with scripts off, steps and wraps, and clears', {s
 });
 
 test('setScripts turns page scripts on and off and reloads', {skip}, async () => {
-  const lab = createLab();
+  const lab = sharedLab();
   try {
     const handle = await lab.preview('<title>before</title><script>document.title="ran"</script>', {trusted: true});
     const page = await lab.engine.open({kind: 'preview', viewport: view, url: handle.url});
@@ -315,7 +316,7 @@ test('setScripts turns page scripts on and off and reloads', {skip}, async () =>
 });
 
 test('popups are closed and reported; dialogs are answered; downloads are refused', {skip}, async () => {
-  const lab = createLab();
+  const lab = sharedLab();
   const site = await localSite({
     '/': `<body style="margin:0"><a href="/pop" target="_blank" style="position:absolute;left:0;top:0;width:300px;height:50px;display:block">pop</a>
 <a href="/file.bin" style="position:absolute;left:0;top:100px;width:300px;height:50px;display:block">get</a>
@@ -352,7 +353,7 @@ test('popups are closed and reported; dialogs are answered; downloads are refuse
 });
 
 test('a preview refuses remote resources and navigation, and no request leaves the machine', {skip}, async () => {
-  const lab = createLab();
+  const lab = sharedLab();
   const remote = await localSite();
   try {
     const html = `<body style="margin:0"><img src="${remote.origin}/x.png"><img src="data:image/gif;base64,R0lGODlhAQABAAAAACw=">
@@ -379,7 +380,7 @@ test('a preview refuses remote resources and navigation, and no request leaves t
 });
 
 test('previews share nothing with browsing: cookies set in a web page are invisible to a preview', {skip}, async () => {
-  const lab = createLab();
+  const lab = sharedLab();
   const site = await localSite({'/': {type: 'text/html', body: '<title>set</title>', headers: {'Set-Cookie': 'k=v; Path=/'}}});
   try {
     const web = await lab.engine.open({kind: 'web', viewport: view, url: site.origin + '/'});
@@ -395,7 +396,7 @@ test('previews share nothing with browsing: cookies set in a web page are invisi
 });
 
 test('closing a page closes its target and a preview page disposes its context', {skip}, async () => {
-  const lab = createLab();
+  const lab = sharedLab();
   try {
     const handle = await lab.preview('<p>x</p>');
     const page = await lab.engine.open({kind: 'preview', viewport: view, url: handle.url});

tests/diagramsChrome.test.ts

@@ -1,4 +1,4 @@
-import test from 'node:test';
+import test, {after} from 'node:test';
 import assert from 'node:assert/strict';
 import http from 'node:http';
 import type {AddressInfo} from 'node:net';
@@ -31,12 +31,25 @@ async function skip(): Promise<string | undefined> {
   return (await chromeSkipReason()) ?? (await mermaidSkip);
 }
 
-async function lab(): Promise<{engine: BrowserEngine; dir: string; done(): Promise<void>}> {
+interface DiagramLab {engine: BrowserEngine; dir: string; done(): Promise<void>}
+
+function freshLab(): DiagramLab {
   const dir = scratchDir('nmsh-diagrams-');
   const engine = createBrowserEngine({profileDir: path.join(dir, 'profile'), idleMs: 60_000});
   return {engine, dir, done: async () => { await engine.shutdown(); fs.rmSync(dir, {recursive: true, force: true, maxRetries: 10, retryDelay: 200}); }};
 }
 
+// Launching Chromium costs seconds on CI runners: tests that only open renderer pages share one browser; each test closes the
+// pages it left open, so the next starts with none. The crash test keeps a browser of its own.
+let shared: DiagramLab | undefined;
+after(async () => { await shared?.done(); shared = undefined; });
+
+async function lab(options: {fresh?: boolean} = {}): Promise<DiagramLab> {
+  if (options.fresh) return freshLab();
+  const base = shared ??= freshLab();
+  return {...base, done: async () => { await Promise.all(base.engine.pages().map(page => page.close().catch(() => undefined))); }};
+}
+
 const request = (source: string, extra: Partial<DiagramRenderRequest> = {}): DiagramRenderRequest => ({source, config: mermaidConfig(THEME), scale: 2, timeoutMs: 10_000, ...extra});
 
 const TYPES: Record<string, string> = {
@@ -176,7 +189,7 @@ test('a library that never finishes is stopped at the timeout; the page is throw
 test('a crashed renderer page is reported, never hangs, and the browser stops cleanly afterwards', async t => {
   const reason = await skip();
   if (reason) { t.skip(reason); return; }
-  const {engine, done} = await lab();
+  const {engine, done} = await lab({fresh: true});
   try {
     const renderer: DiagramRenderer = await engine.openDiagramRenderer!(library!);
     assert.ok((await renderer.render(request(TYPES.flowchart!))).ok);

tests/support/browserFixtures.ts

@@ -93,6 +93,29 @@ export function createLab(options: {idleMs?: number} = {}): Lab {
   return lab;
 }
 
+let shared: Lab | undefined;
+
+/**
+ * One browser for every test in a file that only needs pages: launching Chromium costs seconds on CI runners, so tests that do
+ * not exercise launch, idle shutdown or crashes share it. `dispose()` closes the pages the test left open (each test starts with
+ * none) and keeps the browser; call `disposeSharedLab()` from the file's `after` hook. Lifecycle tests keep `createLab()`.
+ */
+export function sharedLab(): Lab {
+  const lab = shared ??= createLab();
+  return {
+    ...lab,
+    async dispose() {
+      await Promise.all(lab.engine.pages().map(page => page.close().catch(() => undefined)));
+    }
+  };
+}
+
+export async function disposeSharedLab(): Promise<void> {
+  const lab = shared;
+  shared = undefined;
+  await lab?.dispose();
+}
+
 /** Collects a page's events and lets a test wait for one. */
 export class Events {
   readonly all: PageEvent[] = [];