From 6ccf3e9d32058367fdbc92cc22abcf26a4174e55 Mon Sep 17 00:00:00 2001
From: tt-a1i <tt-a1i@users.noreply.github.com>
Date: Fri, 2 Oct 2026 00:09:03 +0800
Subject: [PATCH 1/4] ci: parallelize suites and shard browser acceptance

---
 .github/workflows/ci.yml        | 131 +++++++++++++++++++++++++++-----
 package.json                    |   2 +
 scripts/run-tests.mjs           |  33 +++++---
 tests/scripts/run-tests.test.ts | 119 +++++++++++++++++++++++++++++
 tests/web/openpi-web.e2e.ts     |   2 +
 tests/web/playwright.config.ts  |   4 +-
 6 files changed, 257 insertions(+), 34 deletions(-)
 create mode 100644 tests/scripts/run-tests.test.ts

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6fd63528c..1d0b14637 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -12,9 +12,13 @@ concurrency:
 permissions:
   contents: read
 
+# Keep download caches outside the checkout and still install from the lockfile.
+env:
+  BUN_INSTALL_CACHE_DIR: ${{ github.workspace }}/../bun-install-cache
+
 jobs:
-  test:
-    name: Node ${{ matrix.node-version }}
+  test-node:
+    name: Runtime Node ${{ matrix.node-version }}
     runs-on: ubuntu-latest
     timeout-minutes: 20
     strategy:
@@ -40,7 +44,7 @@ jobs:
             echo "web/dist is missing or stale; run bun run build:web and commit the result"
             exit 1
           fi
-      - run: bun run test
+      - run: bun run test node
       - name: Smoke-test Pi package discovery
         run: |
           agent_dir="$(mktemp -d)"
@@ -175,8 +179,12 @@ jobs:
           wait "$server_pid"
           server_pid=""
 
-  web-e2e:
-    name: Web E2E (Node 22.19.0)
+  web-e2e-shards:
+    name: Web E2E shard ${{ matrix.shard }}/2
+    strategy:
+      fail-fast: false
+      matrix:
+        shard: [1, 2]
     runs-on: ubuntu-latest
     timeout-minutes: 20
     steps:
@@ -189,29 +197,36 @@ jobs:
           bun-version: 1.3.14
       - name: Install dependencies
         run: bun install --frozen-lockfile
+      - name: Cache Playwright browsers
+        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4
+        with:
+          path: ~/.cache/ms-playwright
+          key: playwright-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('bun.lock') }}
       - name: Install Chromium and D-Bus
         run: |
           bunx playwright install --with-deps chromium
           sudo apt-get install --no-install-recommends -y dbus-daemon
-      - run: dbus-run-session -- bun run test:web:e2e
+      # Independent runners isolate each shard's server, settings and filesystem.
+      - run: dbus-run-session -- bun run test:web:e2e --shard=${{ matrix.shard }}/2
         env:
           # The runner's installed Chrome has Ubuntu's native sandbox profile.
           OPENPI_CHROME_PATH: /opt/google/chrome/chrome
       - name: Test Plan Ready provider handoff
+        if: matrix.shard == 1
         run: bunx playwright test --config tests/web/playwright.plan-provider.config.ts
       - name: Upload Playwright failure artifacts
         if: failure()
         uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
         with:
-          name: openpi-web-playwright-results
+          name: openpi-web-playwright-results-${{ matrix.shard }}
           path: |
             /tmp/openpi-web-playwright-results
             /tmp/openpi-web-plan-provider-playwright-results
           if-no-files-found: ignore
           retention-days: 7
 
-  windows-background-terminals:
-    name: Background terminals (Windows)
+  windows-node:
+    name: Runtime Node (Windows)
     runs-on: windows-latest
     timeout-minutes: 15
     steps:
@@ -222,18 +237,92 @@ jobs:
       - uses: oven-sh/setup-bun@0c5077e51419868618aeaa5fe8019c62421857d6 # v2
         with:
           bun-version: 1.3.14
+      - name: Cache Bun downloads
+        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4
+        with:
+          path: ${{ env.BUN_INSTALL_CACHE_DIR }}
+          key: bun-${{ runner.os }}-${{ runner.arch }}-1.3.14-${{ hashFiles('bun.lock') }}
+          restore-keys: bun-${{ runner.os }}-${{ runner.arch }}-1.3.14-
       - name: Install dependencies
         run: bun install --frozen-lockfile
-      - name: Test Windows process lifecycle
-        run: |
-          $testPath = if (Test-Path "tests/extensions/background-terminals/manager.test.ts") {
-            "tests/extensions/background-terminals/manager.test.ts"
-          } else {
-            "extensions/background-terminals/manager.test.ts"
-          }
-          node --test --experimental-strip-types $testPath
-      - name: Test Windows full-suite isolation
-        # Allow the parallel Node suite, serial process tests, and Vitest to finish.
-        # Windows process identity checks make config-write coverage slower here.
+      - name: Test Windows Node suite with process isolation
+        # run-tests.mjs runs background-terminal files after other Node files.
         timeout-minutes: 10
-        run: bun run test
+        run: bun run test node
+
+  test-ui:
+    name: UI ${{ matrix.os }} Node ${{ matrix.node-version }}
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 15
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest]
+        node-version: [22.19.0, 24, 26]
+        include:
+          - os: windows-latest
+            node-version: 22.19.0
+    steps:
+      - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
+      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+        with:
+          node-version: ${{ matrix.node-version }}
+      - uses: oven-sh/setup-bun@0c5077e51419868618aeaa5fe8019c62421857d6 # v2
+        with:
+          bun-version: 1.3.14
+      - name: Cache Bun downloads
+        if: runner.os == 'Windows'
+        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4
+        with:
+          path: ${{ env.BUN_INSTALL_CACHE_DIR }}
+          key: bun-${{ runner.os }}-${{ runner.arch }}-1.3.14-${{ hashFiles('bun.lock') }}
+          restore-keys: bun-${{ runner.os }}-${{ runner.arch }}-1.3.14-
+      - name: Install dependencies
+        run: bun install --frozen-lockfile
+      - run: bun run test ui
+
+  # Keep existing check names for branch protection. always() makes skipped,
+  # cancelled and failed dependencies fail the gates rather than bypass them.
+  test:
+    name: Node ${{ matrix.node-version }}
+    if: always()
+    needs: [test-node, test-ui, windows-node, web-e2e-shards]
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version: [22.19.0, 24, 26]
+    steps:
+      - name: Require all test jobs
+        env:
+          NODE_RESULT: ${{ needs.test-node.result }}
+          UI_RESULT: ${{ needs.test-ui.result }}
+          WINDOWS_RESULT: ${{ needs.windows-node.result }}
+          E2E_RESULT: ${{ needs.web-e2e-shards.result }}
+        run: |
+          test "$NODE_RESULT" = success
+          test "$UI_RESULT" = success
+          test "$WINDOWS_RESULT" = success
+          test "$E2E_RESULT" = success
+
+  windows-background-terminals:
+    name: Background terminals (Windows)
+    if: always()
+    needs: [windows-node, test-ui]
+    runs-on: ubuntu-latest
+    steps:
+      - name: Require Windows runtime and UI tests
+        env:
+          NODE_RESULT: ${{ needs.windows-node.result }}
+          UI_RESULT: ${{ needs.test-ui.result }}
+        run: test "$NODE_RESULT" = success && test "$UI_RESULT" = success
+
+  web-e2e:
+    name: Web E2E (Node 22.19.0)
+    if: always()
+    needs: [web-e2e-shards]
+    runs-on: ubuntu-latest
+    steps:
+      - name: Require every E2E shard and provider handoff
+        env:
+          E2E_RESULT: ${{ needs.web-e2e-shards.result }}
+        run: test "$E2E_RESULT" = success
diff --git a/package.json b/package.json
index 82ecf090f..eaacfe668 100644
--- a/package.json
+++ b/package.json
@@ -140,6 +140,8 @@
     "test:web:e2e:provider": "bun run build:web && playwright test --config tests/web/playwright.provider.config.ts",
     "benchmark:workflow-child-startup": "node --experimental-strip-types scripts/benchmark-workflow-child-startup.mjs",
     "test": "node scripts/run-tests.mjs",
+    "test:node": "node scripts/run-tests.mjs node",
+    "test:ui": "node scripts/run-tests.mjs ui",
     "provenance": "node scripts/provenance.mjs",
     "check:docs-contract": "node scripts/check-docs-contract.mjs"
   },
diff --git a/scripts/run-tests.mjs b/scripts/run-tests.mjs
index 9e0f86314..ca6c5221a 100644
--- a/scripts/run-tests.mjs
+++ b/scripts/run-tests.mjs
@@ -3,6 +3,11 @@ import { resolve } from "node:path";
 import { discoverTestFiles } from "./discover-tests.mjs";
 import { partitionNodeTestsByPlatform } from "./node-test-groups.mjs";
 
+const suite = process.argv[2] ?? "all";
+if (process.argv.length > 3 || !["all", "node", "ui"].includes(suite)) {
+  throw new Error("Usage: node scripts/run-tests.mjs [all|node|ui]");
+}
+
 const files = discoverTestFiles(resolve("tests"));
 const nodeTests = files.filter((file) => file.endsWith(".test.ts"));
 const vitestTests = files.filter((file) => file.endsWith(".spec.ts"));
@@ -23,21 +28,25 @@ function runNodeTests(files, options = []) {
   return result.status ?? 1;
 }
 
-const nodeTestGroups = partitionNodeTestsByPlatform(nodeTests);
-const parallelNodeResult = runNodeTests(nodeTestGroups.parallel);
-if (parallelNodeResult !== 0) {
-  process.exit(parallelNodeResult);
-}
+if (suite !== "ui") {
+  const nodeTestGroups = partitionNodeTestsByPlatform(nodeTests);
+  const parallelNodeResult = runNodeTests(nodeTestGroups.parallel);
+  if (parallelNodeResult !== 0) {
+    process.exit(parallelNodeResult);
+  }
 
-// Windows process-tree tests must not overlap unrelated Node test files.
-// Keep the rest of the suite on Node's default file-level concurrency.
-const serialNodeResult = runNodeTests(nodeTestGroups.serial, [
-  "--test-concurrency=1",
-]);
-if (serialNodeResult !== 0) {
-  process.exit(serialNodeResult);
+  // Windows process-tree tests must not overlap unrelated Node test files.
+  // Keep the rest of the suite on Node's default file-level concurrency.
+  const serialNodeResult = runNodeTests(nodeTestGroups.serial, [
+    "--test-concurrency=1",
+  ]);
+  if (serialNodeResult !== 0) {
+    process.exit(serialNodeResult);
+  }
 }
 
+if (suite === "node") process.exit(0);
+
 // Invoke the CLI module through Node instead of the package-manager shim.
 // Windows installs expose the shim as `vitest.cmd`, which cannot be launched
 // reliably by spawnSync without a shell.
diff --git a/tests/scripts/run-tests.test.ts b/tests/scripts/run-tests.test.ts
new file mode 100644
index 000000000..41f2da2b9
--- /dev/null
+++ b/tests/scripts/run-tests.test.ts
@@ -0,0 +1,119 @@
+import assert from "node:assert/strict";
+import { spawnSync } from "node:child_process";
+import {
+  copyFileSync,
+  mkdirSync,
+  mkdtempSync,
+  rmSync,
+  writeFileSync,
+} from "node:fs";
+import { tmpdir } from "node:os";
+import { join, resolve } from "node:path";
+import test from "node:test";
+
+function fixture() {
+  const root = mkdtempSync(join(tmpdir(), "openpi-test-runner-"));
+  for (const directory of ["scripts", "tests", "node_modules/vitest"]) {
+    mkdirSync(join(root, directory), { recursive: true });
+  }
+  for (const script of [
+    "run-tests.mjs",
+    "discover-tests.mjs",
+    "node-test-groups.mjs",
+  ]) {
+    copyFileSync(resolve("scripts", script), join(root, "scripts", script));
+  }
+  writeFileSync(
+    join(root, "tests", "sample.test.ts"),
+    `
+    import assert from "node:assert/strict";
+    import test from "node:test";
+    test("node suite marker", () => assert.notEqual(process.env.FAIL_SUITE, "node"));
+  `,
+  );
+  writeFileSync(
+    join(root, "tests", "sample.spec.ts"),
+    "// UI discovery fixture\n",
+  );
+  // A tiny CLI stand-in isolates runner selection/exit behavior from Vitest itself.
+  writeFileSync(
+    join(root, "node_modules/vitest/vitest.mjs"),
+    `
+    import assert from "node:assert/strict";
+    assert.equal(process.argv[2], "run");
+    assert.ok(process.argv[3].endsWith("sample.spec.ts"));
+    console.log("ui suite marker");
+    process.exit(process.env.FAIL_SUITE === "ui" ? 7 : 0);
+  `,
+  );
+  return {
+    root,
+    run(args: string[] = [], failSuite = "") {
+      const env: NodeJS.ProcessEnv = { ...process.env, FAIL_SUITE: failSuite };
+      // Start a fresh test runner rather than inheriting this test worker context.
+      delete env.NODE_TEST_CONTEXT;
+      return spawnSync(process.execPath, ["scripts/run-tests.mjs", ...args], {
+        cwd: root,
+        env,
+        encoding: "utf8",
+      });
+    },
+    dispose() {
+      rmSync(root, { recursive: true, force: true });
+    },
+  };
+}
+
+test("split suite commands together cover the unchanged default command", () => {
+  const runner = fixture();
+  try {
+    for (const [args, nodeExpected, uiExpected] of [
+      [[], true, true],
+      [["all"], true, true],
+      [["node"], true, false],
+      [["ui"], false, true],
+    ] as const) {
+      const result = runner.run([...args]);
+      assert.equal(result.status, 0, result.stderr || result.stdout);
+      assert.equal(result.stdout.includes("node suite marker"), nodeExpected);
+      assert.equal(result.stdout.includes("ui suite marker"), uiExpected);
+    }
+  } finally {
+    runner.dispose();
+  }
+});
+
+test("test failures propagate and default execution stops after Node failure", () => {
+  const runner = fixture();
+  try {
+    const node = runner.run(["node"], "node");
+    assert.notEqual(node.status, 0);
+    assert.equal(node.stdout.includes("ui suite marker"), false);
+    assert.equal(runner.run(["ui"], "ui").status, 7);
+    const combined = runner.run([], "node");
+    assert.notEqual(combined.status, 0);
+    assert.equal(combined.stdout.includes("ui suite marker"), false);
+    assert.equal(runner.run([], "ui").status, 7);
+  } finally {
+    runner.dispose();
+  }
+});
+
+test("invalid selection and empty discovery fail before running a partial suite", () => {
+  const runner = fixture();
+  try {
+    for (const args of [["unknown"], ["node", "extra"]]) {
+      const result = runner.run(args);
+      assert.notEqual(result.status, 0);
+      assert.match(result.stderr, /Usage:/);
+      assert.equal(result.stdout.includes("suite marker"), false);
+    }
+    rmSync(join(runner.root, "tests", "sample.spec.ts"));
+    const empty = runner.run(["node"]);
+    assert.notEqual(empty.status, 0);
+    assert.match(empty.stderr, /both suites must be non-empty/);
+    assert.equal(empty.stdout.includes("suite marker"), false);
+  } finally {
+    runner.dispose();
+  }
+});
diff --git a/tests/web/openpi-web.e2e.ts b/tests/web/openpi-web.e2e.ts
index 670fe0a9f..163a22956 100644
--- a/tests/web/openpi-web.e2e.ts
+++ b/tests/web/openpi-web.e2e.ts
@@ -570,6 +570,8 @@ test("provider failures remain visible after refresh without discarding partial
   await expect(page.getByText("Partial answer")).toBeVisible();
   await expect(page.getByText("模型请求已停止")).toBeVisible();
   await expect(page.getByRole("alert")).toHaveCount(0);
+  // Drain snapshot handlers before the per-test request context is disposed.
+  await page.unrouteAll({ behavior: "wait" });
 });
 
 async function openWorkbench(page: Page) {
diff --git a/tests/web/playwright.config.ts b/tests/web/playwright.config.ts
index 3da0c9ef8..b90916cf5 100644
--- a/tests/web/playwright.config.ts
+++ b/tests/web/playwright.config.ts
@@ -41,7 +41,9 @@ export default defineConfig({
     "tests/web/subagent-inspection.e2e.ts",
   ],
   outputDir: outputDirectory,
-  fullyParallel: false,
+  // Shard individual cases, including the large workbench file. Each runner
+  // still uses one worker so tests cannot mutate its shared server concurrently.
+  fullyParallel: true,
   workers: 1,
   timeout: 30_000,
   reporter: "list",

From 05023c65963a3341c028cbd3a26216df3f195ca6 Mon Sep 17 00:00:00 2001
From: tt-a1i <tt-a1i@users.noreply.github.com>
Date: Fri, 2 Oct 2026 00:24:27 +0800
Subject: [PATCH 2/4] ci: cache system packages and isolate model fixtures

---
 .github/workflows/ci.yml    | 20 +++++++++++++++++++-
 tests/web/openpi-web.e2e.ts | 14 ++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1d0b14637..652d2e115 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,6 +15,7 @@ permissions:
 # Keep download caches outside the checkout and still install from the lockfile.
 env:
   BUN_INSTALL_CACHE_DIR: ${{ github.workspace }}/../bun-install-cache
+  CI_APT_CACHE_DIR: ${{ github.workspace }}/../apt-download-cache
 
 jobs:
   test-node:
@@ -185,7 +186,7 @@ jobs:
       fail-fast: false
       matrix:
         shard: [1, 2]
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     timeout-minutes: 20
     steps:
       - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
@@ -202,7 +203,24 @@ jobs:
         with:
           path: ~/.cache/ms-playwright
           key: playwright-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('bun.lock') }}
+      - name: Prepare system dependency download cache
+        run: |
+          mkdir -p "$CI_APT_CACHE_DIR"
+          sudo tee /etc/apt/apt.conf.d/99-openpi-ci-cache >/dev/null <<EOF
+          Dir::Cache::archives "$CI_APT_CACHE_DIR";
+          APT::Keep-Downloaded-Packages "true";
+          Binary::apt-get::APT::Keep-Downloaded-Packages "true";
+          Acquire::Retries "2";
+          Acquire::http::Timeout "30";
+          Acquire::https::Timeout "30";
+          EOF
+      - name: Cache Chromium system package downloads
+        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4
+        with:
+          path: ${{ env.CI_APT_CACHE_DIR }}/*.deb
+          key: apt-${{ runner.os }}-${{ runner.arch }}-ubuntu24-${{ hashFiles('bun.lock') }}
       - name: Install Chromium and D-Bus
+        timeout-minutes: 6
         run: |
           bunx playwright install --with-deps chromium
           sudo apt-get install --no-install-recommends -y dbus-daemon
diff --git a/tests/web/openpi-web.e2e.ts b/tests/web/openpi-web.e2e.ts
index 163a22956..7a8498c98 100644
--- a/tests/web/openpi-web.e2e.ts
+++ b/tests/web/openpi-web.e2e.ts
@@ -3069,6 +3069,13 @@ test("same-named model selection sends the exact identity for an active Session"
     const snapshot = await response.json();
     selectedSessionPath = snapshot.selectedSession.path;
     snapshot.runtime.status = "idle";
+    // Model-selection fixtures must not inherit the Host's thinking capability.
+    snapshot.thinking = {
+      ...snapshot.thinking,
+      level: "off",
+      available: [],
+      supported: false,
+    };
     snapshot.models = [
       {
         provider: "provider-alpha",
@@ -3158,6 +3165,13 @@ test("finds and selects a model omitted from the bounded snapshot", async ({
     activeSessionId = snapshot.currentSessionId;
     activeSessionPath = snapshot.selectedSession.path;
     snapshot.runtime.status = "idle";
+    // Model-selection fixtures must not inherit the Host's thinking capability.
+    snapshot.thinking = {
+      ...snapshot.thinking,
+      level: "off",
+      available: [],
+      supported: false,
+    };
     snapshot.models =
       selectedIdentity === "provider-hidden/needle-251"
         ? [

From 833a7300d0184bcc3b423bb455d6d962c5d595fc Mon Sep 17 00:00:00 2001
From: tt-a1i <tt-a1i@users.noreply.github.com>
Date: Fri, 2 Oct 2026 00:36:45 +0800
Subject: [PATCH 3/4] ci: use restorable cache paths outside the checkout

---
 .github/workflows/ci.yml | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 652d2e115..9dbcf44aa 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,8 +14,7 @@ permissions:
 
 # Keep download caches outside the checkout and still install from the lockfile.
 env:
-  BUN_INSTALL_CACHE_DIR: ${{ github.workspace }}/../bun-install-cache
-  CI_APT_CACHE_DIR: ${{ github.workspace }}/../apt-download-cache
+  CI_APT_CACHE_DIR: /tmp/openpi-apt-download-cache
 
 jobs:
   test-node:
@@ -35,6 +34,8 @@ jobs:
         with:
           bun-version: 1.3.14
       - name: Install dependencies
+        env:
+          BUN_INSTALL_CACHE_DIR: ${{ runner.temp }}/bun-install-cache
         run: bun install --frozen-lockfile
       - run: bun run check
       - name: Verify committed Web build
@@ -197,6 +198,8 @@ jobs:
         with:
           bun-version: 1.3.14
       - name: Install dependencies
+        env:
+          BUN_INSTALL_CACHE_DIR: ${{ runner.temp }}/bun-install-cache
         run: bun install --frozen-lockfile
       - name: Cache Playwright browsers
         uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4
@@ -219,8 +222,9 @@ jobs:
         with:
           path: ${{ env.CI_APT_CACHE_DIR }}/*.deb
           key: apt-${{ runner.os }}-${{ runner.arch }}-ubuntu24-${{ hashFiles('bun.lock') }}
+          restore-keys: apt-${{ runner.os }}-${{ runner.arch }}-ubuntu24-
       - name: Install Chromium and D-Bus
-        timeout-minutes: 6
+        timeout-minutes: 10
         run: |
           bunx playwright install --with-deps chromium
           sudo apt-get install --no-install-recommends -y dbus-daemon
@@ -258,10 +262,12 @@ jobs:
       - name: Cache Bun downloads
         uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4
         with:
-          path: ${{ env.BUN_INSTALL_CACHE_DIR }}
+          path: ${{ runner.temp }}/bun-install-cache
           key: bun-${{ runner.os }}-${{ runner.arch }}-1.3.14-${{ hashFiles('bun.lock') }}
           restore-keys: bun-${{ runner.os }}-${{ runner.arch }}-1.3.14-
       - name: Install dependencies
+        env:
+          BUN_INSTALL_CACHE_DIR: ${{ runner.temp }}/bun-install-cache
         run: bun install --frozen-lockfile
       - name: Test Windows Node suite with process isolation
         # run-tests.mjs runs background-terminal files after other Node files.
@@ -292,10 +298,12 @@ jobs:
         if: runner.os == 'Windows'
         uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4
         with:
-          path: ${{ env.BUN_INSTALL_CACHE_DIR }}
+          path: ${{ runner.temp }}/bun-install-cache
           key: bun-${{ runner.os }}-${{ runner.arch }}-1.3.14-${{ hashFiles('bun.lock') }}
           restore-keys: bun-${{ runner.os }}-${{ runner.arch }}-1.3.14-
       - name: Install dependencies
+        env:
+          BUN_INSTALL_CACHE_DIR: ${{ runner.temp }}/bun-install-cache
         run: bun install --frozen-lockfile
       - run: bun run test ui
 

From 4a31a17b2e4611fa04b8b1547e9a3e3f637e7609 Mon Sep 17 00:00:00 2001
From: tt-a1i <tt-a1i@users.noreply.github.com>
Date: Fri, 2 Oct 2026 11:49:21 +0800
Subject: [PATCH 4/4] ci: shard Windows Node tests across isolated runners

---
 .github/workflows/ci.yml               | 17 ++++-
 scripts/discover-tests.d.mts           |  1 +
 scripts/node-test-groups.d.mts         |  2 +
 scripts/node-test-groups.mjs           | 17 +++++
 scripts/run-tests.mjs                  | 43 ++++++++++--
 tests/scripts/node-test-groups.test.ts | 20 +++++-
 tests/scripts/run-tests.test.ts        | 90 +++++++++++++++++++++++++-
 7 files changed, 180 insertions(+), 10 deletions(-)
 create mode 100644 scripts/discover-tests.d.mts

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9dbcf44aa..fe7a54e9a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -248,9 +248,19 @@ jobs:
           retention-days: 7
 
   windows-node:
-    name: Runtime Node (Windows)
+    name: Runtime Node (Windows ${{ matrix.group }})
     runs-on: windows-latest
     timeout-minutes: 15
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - group: parallel 1/2
+            arguments: node-parallel --shard=1/2
+          - group: parallel 2/2
+            arguments: node-parallel --shard=2/2
+          - group: isolated processes
+            arguments: node-serial
     steps:
       - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
@@ -270,9 +280,10 @@ jobs:
           BUN_INSTALL_CACHE_DIR: ${{ runner.temp }}/bun-install-cache
         run: bun install --frozen-lockfile
       - name: Test Windows Node suite with process isolation
-        # run-tests.mjs runs background-terminal files after other Node files.
+        # Process tests stay serial inside their own VM; ordinary files are
+        # split into disjoint shards on separate VMs, with every shard required.
         timeout-minutes: 10
-        run: bun run test node
+        run: bun run test ${{ matrix.arguments }}
 
   test-ui:
     name: UI ${{ matrix.os }} Node ${{ matrix.node-version }}
diff --git a/scripts/discover-tests.d.mts b/scripts/discover-tests.d.mts
new file mode 100644
index 000000000..043193453
--- /dev/null
+++ b/scripts/discover-tests.d.mts
@@ -0,0 +1 @@
+export function discoverTestFiles(root?: string): string[];
diff --git a/scripts/node-test-groups.d.mts b/scripts/node-test-groups.d.mts
index ed8bfd983..25c69b9c3 100644
--- a/scripts/node-test-groups.d.mts
+++ b/scripts/node-test-groups.d.mts
@@ -2,3 +2,5 @@ export function partitionNodeTestsByPlatform(
   files: string[],
   platform?: NodeJS.Platform,
 ): { parallel: string[]; serial: string[] };
+
+export function selectNodeTestShard(files: string[], shard: string): string[];
diff --git a/scripts/node-test-groups.mjs b/scripts/node-test-groups.mjs
index a45b071d6..f0c7d2241 100644
--- a/scripts/node-test-groups.mjs
+++ b/scripts/node-test-groups.mjs
@@ -31,3 +31,20 @@ export function partitionNodeTestsByPlatform(
   }
   return { parallel, serial };
 }
+
+export function selectNodeTestShard(files, shard) {
+  const match = /^([1-9]\d*)\/([1-9]\d*)$/.exec(shard);
+  const index = Number(match?.[1]);
+  const total = Number(match?.[2]);
+  if (
+    !Number.isSafeInteger(index) ||
+    !Number.isSafeInteger(total) ||
+    index > total ||
+    total > files.length
+  ) {
+    throw new Error(
+      "Invalid Node test shard: expected index/total with no empty shards.",
+    );
+  }
+  return files.filter((_, fileIndex) => fileIndex % total === index - 1);
+}
diff --git a/scripts/run-tests.mjs b/scripts/run-tests.mjs
index ca6c5221a..dfec12fe2 100644
--- a/scripts/run-tests.mjs
+++ b/scripts/run-tests.mjs
@@ -1,11 +1,22 @@
 import { spawnSync } from "node:child_process";
 import { resolve } from "node:path";
 import { discoverTestFiles } from "./discover-tests.mjs";
-import { partitionNodeTestsByPlatform } from "./node-test-groups.mjs";
+import {
+  partitionNodeTestsByPlatform,
+  selectNodeTestShard,
+} from "./node-test-groups.mjs";
 
 const suite = process.argv[2] ?? "all";
-if (process.argv.length > 3 || !["all", "node", "ui"].includes(suite)) {
-  throw new Error("Usage: node scripts/run-tests.mjs [all|node|ui]");
+const shardArgument = process.argv[3];
+if (
+  process.argv.length > 4 ||
+  !["all", "node", "ui", "node-parallel", "node-serial"].includes(suite) ||
+  (shardArgument !== undefined &&
+    (suite !== "node-parallel" || !shardArgument.startsWith("--shard=")))
+) {
+  throw new Error(
+    "Usage: node scripts/run-tests.mjs [all|node|ui|node-parallel [--shard=index/total]|node-serial]",
+  );
 }
 
 const files = discoverTestFiles(resolve("tests"));
@@ -29,7 +40,29 @@ function runNodeTests(files, options = []) {
 }
 
 if (suite !== "ui") {
-  const nodeTestGroups = partitionNodeTestsByPlatform(nodeTests);
+  // Explicit groups use the Windows isolation boundary on every platform so
+  // their coverage can also be verified locally. Each CI group owns a VM.
+  const grouped = suite === "node-parallel" || suite === "node-serial";
+  const nodeTestGroups = partitionNodeTestsByPlatform(
+    nodeTests,
+    grouped ? "win32" : process.platform,
+  );
+  if (
+    grouped &&
+    (!nodeTestGroups.parallel.length || !nodeTestGroups.serial.length)
+  ) {
+    throw new Error("Both isolated Node test groups must be non-empty.");
+  }
+  if (suite === "node-serial") nodeTestGroups.parallel = [];
+  if (suite === "node-parallel") {
+    nodeTestGroups.serial = [];
+    if (shardArgument !== undefined) {
+      nodeTestGroups.parallel = selectNodeTestShard(
+        nodeTestGroups.parallel,
+        shardArgument.slice("--shard=".length),
+      );
+    }
+  }
   const parallelNodeResult = runNodeTests(nodeTestGroups.parallel);
   if (parallelNodeResult !== 0) {
     process.exit(parallelNodeResult);
@@ -45,7 +78,7 @@ if (suite !== "ui") {
   }
 }
 
-if (suite === "node") process.exit(0);
+if (suite.startsWith("node")) process.exit(0);
 
 // Invoke the CLI module through Node instead of the package-manager shim.
 // Windows installs expose the shim as `vitest.cmd`, which cannot be launched
diff --git a/tests/scripts/node-test-groups.test.ts b/tests/scripts/node-test-groups.test.ts
index 86c0912b5..ab2b1ca2d 100644
--- a/tests/scripts/node-test-groups.test.ts
+++ b/tests/scripts/node-test-groups.test.ts
@@ -1,7 +1,11 @@
 import assert from "node:assert/strict";
 import { resolve } from "node:path";
 import test from "node:test";
-import { partitionNodeTestsByPlatform } from "../../scripts/node-test-groups.mjs";
+import {
+  partitionNodeTestsByPlatform,
+  selectNodeTestShard,
+} from "../../scripts/node-test-groups.mjs";
+import { discoverTestFiles } from "../../scripts/discover-tests.mjs";
 
 const backgroundTest = resolve(
   "tests",
@@ -42,3 +46,17 @@ test("non-Windows keeps all Node files in the parallel group", () => {
     },
   );
 });
+
+test("CI's Windows shards are disjoint and cover all discovered Node files", () => {
+  const files = discoverTestFiles().filter((file) => file.endsWith(".test.ts"));
+  const { parallel, serial } = partitionNodeTestsByPlatform(files, "win32");
+  const groups = [
+    selectNodeTestShard(parallel, "1/2"),
+    selectNodeTestShard(parallel, "2/2"),
+    serial,
+  ];
+  assert.ok(groups.every((group) => group.length > 0));
+  const selected = groups.flat();
+  assert.equal(new Set(selected).size, selected.length);
+  assert.deepEqual([...selected].sort(), [...files].sort());
+});
diff --git a/tests/scripts/run-tests.test.ts b/tests/scripts/run-tests.test.ts
index 41f2da2b9..881da9491 100644
--- a/tests/scripts/run-tests.test.ts
+++ b/tests/scripts/run-tests.test.ts
@@ -13,7 +13,11 @@ import test from "node:test";
 
 function fixture() {
   const root = mkdtempSync(join(tmpdir(), "openpi-test-runner-"));
-  for (const directory of ["scripts", "tests", "node_modules/vitest"]) {
+  for (const directory of [
+    "scripts",
+    "tests/extensions/background-terminals",
+    "node_modules/vitest",
+  ]) {
     mkdirSync(join(root, directory), { recursive: true });
   }
   for (const script of [
@@ -31,6 +35,18 @@ function fixture() {
     test("node suite marker", () => assert.notEqual(process.env.FAIL_SUITE, "node"));
   `,
   );
+  writeFileSync(
+    join(root, "tests", "second.test.ts"),
+    `import test from "node:test"; test("second node marker", () => {});`,
+  );
+  writeFileSync(
+    join(root, "tests/extensions/background-terminals", "process.test.ts"),
+    `
+    import assert from "node:assert/strict";
+    import test from "node:test";
+    test("isolated process marker", () => assert.notEqual(process.env.FAIL_SUITE, "serial"));
+    `,
+  );
   writeFileSync(
     join(root, "tests", "sample.spec.ts"),
     "// UI discovery fixture\n",
@@ -99,6 +115,78 @@ test("test failures propagate and default execution stops after Node failure", (
   }
 });
 
+test("isolated shards cover every Node file exactly once and propagate failures", () => {
+  const runner = fixture();
+  try {
+    const outputs = [
+      runner.run(["node-parallel", "--shard=1/2"]),
+      runner.run(["node-parallel", "--shard=2/2"]),
+      runner.run(["node-serial"]),
+    ];
+    for (const result of outputs) {
+      assert.equal(result.status, 0, result.stderr || result.stdout);
+      assert.equal(result.stdout.includes("ui suite marker"), false);
+    }
+    for (const marker of [
+      "node suite marker",
+      "second node marker",
+      "isolated process marker",
+    ]) {
+      assert.equal(
+        outputs.filter((result) => result.stdout.includes(marker)).length,
+        1,
+      );
+    }
+    assert.equal(outputs[2].stdout.includes("isolated process marker"), true);
+    assert.notEqual(
+      runner.run(["node-parallel", "--shard=1/2"], "node").status,
+      0,
+    );
+    assert.notEqual(runner.run(["node-serial"], "serial").status, 0);
+    assert.notEqual(runner.run([], "serial").status, 0);
+  } finally {
+    runner.dispose();
+  }
+});
+
+test("invalid and empty shards fail before executing any tests", () => {
+  const runner = fixture();
+  try {
+    for (const shard of [
+      "0/2",
+      "3/2",
+      "1/0",
+      "1/3",
+      "1/2junk",
+      "1/9007199254740992",
+    ]) {
+      const result = runner.run(["node-parallel", `--shard=${shard}`]);
+      assert.notEqual(result.status, 0);
+      assert.match(result.stderr, /Invalid Node test shard/);
+      assert.equal(result.stdout.includes("marker"), false);
+    }
+    for (const args of [
+      ["node-serial", "--shard=1/2"],
+      ["node-parallel", "extra"],
+      ["node-parallel", "--shard=1/2", "extra"],
+    ]) {
+      assert.match(runner.run(args).stderr, /Usage:/);
+    }
+    rmSync(join(runner.root, "tests/extensions/background-terminals"), {
+      recursive: true,
+    });
+    const result = runner.run(["node-parallel"]);
+    assert.notEqual(result.status, 0);
+    assert.match(
+      result.stderr,
+      /Both isolated Node test groups must be non-empty/,
+    );
+    assert.equal(result.stdout.includes("marker"), false);
+  } finally {
+    runner.dispose();
+  }
+});
+
 test("invalid selection and empty discovery fail before running a partial suite", () => {
   const runner = fixture();
   try {