From f85e89dea5e74f78d30babdc861ed26ab95c8b3f Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Mon, 3 Aug 2026 19:11:33 +0000
Subject: [PATCH 01/15] fix(core): discovery url handling, error code review
 helper, and pack-n-play test timeouts

---
 .../test/fixtures/esm-package/test/test.js    |  3 ++-
 .../test/fixtures/leaky/test/test.ts          |  3 ++-
 .../test/fixtures/pass/test/test.ts           |  3 ++-
 core/dev-packages/pack-n-play/test/test.ts    |  5 +++--
 core/packages/gcp-metadata/src/index.ts       | 22 ++++++++++++++-----
 .../nodejs-googleapis-common/src/discovery.ts | 12 +++++++---
 .../test/test.discovery.ts                    |  4 ++--
 7 files changed, 37 insertions(+), 15 deletions(-)

diff --git a/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js b/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
index 037babedf227..2adbf53d289c 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
+++ b/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
@@ -16,7 +16,8 @@ import {packNTest} from 'pack-n-play';
 import * as assert from 'assert';
 import {describe, it} from 'mocha';
 
-describe('ESM package', () => {
+describe('ESM package', function () {
+  this.timeout(120000);
   it('should support esm property', () =>
     packNTest({
       sample: {
diff --git a/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts b/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
index 3a9dc7f39b39..9c56bc9c0741 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
+++ b/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
@@ -16,7 +16,8 @@ import {packNTest} from 'pack-n-play';
 import * as assert from 'assert';
 import {describe, it} from 'mocha';
 
-describe('leaky tests', () => {
+describe('leaky tests', function () {
+  this.timeout(120000);
   it('should fail packing n testing', async () => {
     await assert.rejects(
       packNTest({
diff --git a/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts b/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
index 2dd02fb27cff..50d0d07d620d 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
+++ b/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
@@ -15,7 +15,8 @@
 import {packNTest} from 'pack-n-play';
 import {describe, it} from 'mocha';
 
-describe('passing tests', () => {
+describe('passing tests', function () {
+  this.timeout(120000);
   it('should pass the test', async () => {
     await packNTest({
       sample: {
diff --git a/core/dev-packages/pack-n-play/test/test.ts b/core/dev-packages/pack-n-play/test/test.ts
index da954b94ba08..06aef544b4e7 100644
--- a/core/dev-packages/pack-n-play/test/test.ts
+++ b/core/dev-packages/pack-n-play/test/test.ts
@@ -18,7 +18,8 @@ import execa = require('execa');
 import {describe, it} from 'mocha';
 
 describe('pack-n-play', () => {
-  it('should run tests', async () => {
+  it('should run tests', async function () {
+    this.timeout(600000); // 10 minutes
     const fixturesPath = path.resolve('./test/fixtures');
     const dirs = fs
       .readdirSync(fixturesPath)
@@ -29,7 +30,7 @@ describe('pack-n-play', () => {
         stdio: 'inherit',
         cwd: dir,
       };
-      await execa('npm', ['install'], opts);
+      await execa('npm', ['install', '--no-audit', '--no-fund'], opts);
       await execa('npm', ['link', '../../../'], opts);
       await execa('npm', ['test'], opts);
     }
diff --git a/core/packages/gcp-metadata/src/index.ts b/core/packages/gcp-metadata/src/index.ts
index 723fcf1d3f1e..c591ada49ef8 100644
--- a/core/packages/gcp-metadata/src/index.ts
+++ b/core/packages/gcp-metadata/src/index.ts
@@ -383,12 +383,24 @@ export async function isAvailable() {
           if (err.response && err.response.status === 404) {
             return false;
           } else {
+            const errObj = e as any;
+            const getErrorCode = (err: any): string => {
+              let target = err;
+              if (
+                target instanceof Error &&
+                target.cause &&
+                !('code' in target) &&
+                target.name !== 'AggregateError'
+              ) {
+                target = target.cause;
+              }
+              return target?.code ? target.code.toString() : 'UNKNOWN';
+            };
+
             const codes =
-              e instanceof Error && e.name === 'AggregateError'
-                ? (e as any).errors.map((error: any) =>
-                    error.code ? error.code.toString() : 'UNKNOWN',
-                  )
-                : [err.code ? err.code.toString() : 'UNKNOWN'];
+              errObj instanceof Error && errObj.name === 'AggregateError'
+                ? (errObj as any).errors.map(getErrorCode)
+                : [getErrorCode(errObj)];
 
             const isExpected = codes.every((code: string) =>
               [
diff --git a/core/packages/nodejs-googleapis-common/src/discovery.ts b/core/packages/nodejs-googleapis-common/src/discovery.ts
index c00c663bed28..2a665dba0291 100644
--- a/core/packages/nodejs-googleapis-common/src/discovery.ts
+++ b/core/packages/nodejs-googleapis-common/src/discovery.ts
@@ -13,7 +13,6 @@
 
 import * as fs from 'fs';
 import {Gaxios} from 'gaxios';
-import resolve = require('url');
 import * as util from 'util';
 
 import {GlobalOptions, ServiceOptions, APIRequestParams} from './api';
@@ -136,8 +135,15 @@ export class Discovery {
     apiDiscoveryUrl: string | {url?: string},
   ): Promise<EndpointCreator> {
     if (typeof apiDiscoveryUrl === 'string') {
-      const parts = resolve.parse(apiDiscoveryUrl);
-      if (apiDiscoveryUrl && !parts.protocol) {
+      let isUrl = false;
+      try {
+        const parsed = new URL(apiDiscoveryUrl);
+        isUrl = parsed.protocol === 'http:' || parsed.protocol === 'https:';
+      } catch (e) {
+        // Not a valid URL
+      }
+
+      if (apiDiscoveryUrl && !isUrl) {
         this.log('Reading from file ' + apiDiscoveryUrl);
         const file = await readFile(apiDiscoveryUrl, {encoding: 'utf8'});
         return this.makeEndpoint(JSON.parse(file));
diff --git a/core/packages/nodejs-googleapis-common/test/test.discovery.ts b/core/packages/nodejs-googleapis-common/test/test.discovery.ts
index 0e656c5fb6b1..6745982a218f 100644
--- a/core/packages/nodejs-googleapis-common/test/test.discovery.ts
+++ b/core/packages/nodejs-googleapis-common/test/test.discovery.ts
@@ -24,7 +24,7 @@ describe(__filename, () => {
     nock.cleanAll();
   });
   it('should discover an API', async () => {
-    const discoUrl = 'http://test.local';
+    const discoUrl = 'http://test.local:80';
     const scope = nock(discoUrl)
       .get('/')
       .replyWithFile(200, './test/fixtures/compute-v1.json', {
@@ -37,7 +37,7 @@ describe(__filename, () => {
     scope.done();
   });
   it('should discover an API through second weird path', async () => {
-    const discoUrl = 'http://test.local';
+    const discoUrl = 'http://test.local:80';
     const scope = nock(discoUrl)
       .get('/')
       .replyWithFile(200, './test/fixtures/compute-v1.json', {

From 639081b2a9dcd5ceb098a633927c4b4b60c86d6f Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Mon, 3 Aug 2026 19:42:11 +0000
Subject: [PATCH 02/15] fix(gcp-metadata): use recursive getErrorCodes helper
 for nested wrapper error causes

---
 core/packages/gcp-metadata/src/index.ts | 26 ++++++++++++-------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/core/packages/gcp-metadata/src/index.ts b/core/packages/gcp-metadata/src/index.ts
index c591ada49ef8..3d98d38f9b03 100644
--- a/core/packages/gcp-metadata/src/index.ts
+++ b/core/packages/gcp-metadata/src/index.ts
@@ -384,23 +384,21 @@ export async function isAvailable() {
             return false;
           } else {
             const errObj = e as any;
-            const getErrorCode = (err: any): string => {
-              let target = err;
-              if (
-                target instanceof Error &&
-                target.cause &&
-                !('code' in target) &&
-                target.name !== 'AggregateError'
-              ) {
-                target = target.cause;
+            const getErrorCodes = (err: any): string[] => {
+              if (!err) return ['UNKNOWN'];
+              if (err.name === 'AggregateError' && Array.isArray(err.errors)) {
+                return err.errors.flatMap(getErrorCodes);
               }
-              return target?.code ? target.code.toString() : 'UNKNOWN';
+              if (err.code) {
+                return [err.code.toString()];
+              }
+              if (err.cause) {
+                return getErrorCodes(err.cause);
+              }
+              return ['UNKNOWN'];
             };
 
-            const codes =
-              errObj instanceof Error && errObj.name === 'AggregateError'
-                ? (errObj as any).errors.map(getErrorCode)
-                : [getErrorCode(errObj)];
+            const codes = getErrorCodes(errObj);
 
             const isExpected = codes.every((code: string) =>
               [

From 4bc3be36f597d493f15b907a29251cc54922c38b Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Mon, 3 Aug 2026 20:08:40 +0000
Subject: [PATCH 03/15] chore(core): remove pack-n-play timeout fixes (moved to
 #9021)

---
 .../pack-n-play/test/fixtures/esm-package/test/test.js       | 3 +--
 .../pack-n-play/test/fixtures/leaky/test/test.ts             | 3 +--
 .../dev-packages/pack-n-play/test/fixtures/pass/test/test.ts | 3 +--
 core/dev-packages/pack-n-play/test/test.ts                   | 5 ++---
 4 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js b/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
index 2adbf53d289c..037babedf227 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
+++ b/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
@@ -16,8 +16,7 @@ import {packNTest} from 'pack-n-play';
 import * as assert from 'assert';
 import {describe, it} from 'mocha';
 
-describe('ESM package', function () {
-  this.timeout(120000);
+describe('ESM package', () => {
   it('should support esm property', () =>
     packNTest({
       sample: {
diff --git a/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts b/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
index 9c56bc9c0741..3a9dc7f39b39 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
+++ b/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
@@ -16,8 +16,7 @@ import {packNTest} from 'pack-n-play';
 import * as assert from 'assert';
 import {describe, it} from 'mocha';
 
-describe('leaky tests', function () {
-  this.timeout(120000);
+describe('leaky tests', () => {
   it('should fail packing n testing', async () => {
     await assert.rejects(
       packNTest({
diff --git a/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts b/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
index 50d0d07d620d..2dd02fb27cff 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
+++ b/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
@@ -15,8 +15,7 @@
 import {packNTest} from 'pack-n-play';
 import {describe, it} from 'mocha';
 
-describe('passing tests', function () {
-  this.timeout(120000);
+describe('passing tests', () => {
   it('should pass the test', async () => {
     await packNTest({
       sample: {
diff --git a/core/dev-packages/pack-n-play/test/test.ts b/core/dev-packages/pack-n-play/test/test.ts
index 06aef544b4e7..da954b94ba08 100644
--- a/core/dev-packages/pack-n-play/test/test.ts
+++ b/core/dev-packages/pack-n-play/test/test.ts
@@ -18,8 +18,7 @@ import execa = require('execa');
 import {describe, it} from 'mocha';
 
 describe('pack-n-play', () => {
-  it('should run tests', async function () {
-    this.timeout(600000); // 10 minutes
+  it('should run tests', async () => {
     const fixturesPath = path.resolve('./test/fixtures');
     const dirs = fs
       .readdirSync(fixturesPath)
@@ -30,7 +29,7 @@ describe('pack-n-play', () => {
         stdio: 'inherit',
         cwd: dir,
       };
-      await execa('npm', ['install', '--no-audit', '--no-fund'], opts);
+      await execa('npm', ['install'], opts);
       await execa('npm', ['link', '../../../'], opts);
       await execa('npm', ['test'], opts);
     }

From ef76bc01bb38746c27b998ea7476f91c7d6ab0fc Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Mon, 3 Aug 2026 20:17:02 +0000
Subject: [PATCH 04/15] chore(core): add pack-n-play timeout fixes back to core
 PR

---
 .../pack-n-play/test/fixtures/esm-package/test/test.js       | 3 ++-
 .../pack-n-play/test/fixtures/leaky/test/test.ts             | 3 ++-
 .../dev-packages/pack-n-play/test/fixtures/pass/test/test.ts | 3 ++-
 core/dev-packages/pack-n-play/test/test.ts                   | 5 +++--
 4 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js b/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
index 037babedf227..2adbf53d289c 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
+++ b/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
@@ -16,7 +16,8 @@ import {packNTest} from 'pack-n-play';
 import * as assert from 'assert';
 import {describe, it} from 'mocha';
 
-describe('ESM package', () => {
+describe('ESM package', function () {
+  this.timeout(120000);
   it('should support esm property', () =>
     packNTest({
       sample: {
diff --git a/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts b/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
index 3a9dc7f39b39..9c56bc9c0741 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
+++ b/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
@@ -16,7 +16,8 @@ import {packNTest} from 'pack-n-play';
 import * as assert from 'assert';
 import {describe, it} from 'mocha';
 
-describe('leaky tests', () => {
+describe('leaky tests', function () {
+  this.timeout(120000);
   it('should fail packing n testing', async () => {
     await assert.rejects(
       packNTest({
diff --git a/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts b/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
index 2dd02fb27cff..50d0d07d620d 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
+++ b/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
@@ -15,7 +15,8 @@
 import {packNTest} from 'pack-n-play';
 import {describe, it} from 'mocha';
 
-describe('passing tests', () => {
+describe('passing tests', function () {
+  this.timeout(120000);
   it('should pass the test', async () => {
     await packNTest({
       sample: {
diff --git a/core/dev-packages/pack-n-play/test/test.ts b/core/dev-packages/pack-n-play/test/test.ts
index da954b94ba08..06aef544b4e7 100644
--- a/core/dev-packages/pack-n-play/test/test.ts
+++ b/core/dev-packages/pack-n-play/test/test.ts
@@ -18,7 +18,8 @@ import execa = require('execa');
 import {describe, it} from 'mocha';
 
 describe('pack-n-play', () => {
-  it('should run tests', async () => {
+  it('should run tests', async function () {
+    this.timeout(600000); // 10 minutes
     const fixturesPath = path.resolve('./test/fixtures');
     const dirs = fs
       .readdirSync(fixturesPath)
@@ -29,7 +30,7 @@ describe('pack-n-play', () => {
         stdio: 'inherit',
         cwd: dir,
       };
-      await execa('npm', ['install'], opts);
+      await execa('npm', ['install', '--no-audit', '--no-fund'], opts);
       await execa('npm', ['link', '../../../'], opts);
       await execa('npm', ['test'], opts);
     }

From ac1f4781c303d05946bba244f9dc8c18d07339bf Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Mon, 3 Aug 2026 21:07:52 +0000
Subject: [PATCH 05/15] add tests for error.cause and AggregateError

---
 core/packages/gcp-metadata/test/index.test.ts | 39 +++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/core/packages/gcp-metadata/test/index.test.ts b/core/packages/gcp-metadata/test/index.test.ts
index 83517852b622..f88a018efffa 100644
--- a/core/packages/gcp-metadata/test/index.test.ts
+++ b/core/packages/gcp-metadata/test/index.test.ts
@@ -493,6 +493,45 @@ describe('unit test', () => {
     });
   });
 
+  it('should fail on isAvailable if ENOTFOUND is wrapped in error.cause', async () => {
+    const secondary = secondaryHostRequest(500, 'ENOTFOUND');
+    const innerErr = Object.assign(new Error('ENOTFOUND'), {code: 'ENOTFOUND'});
+    const wrapperErr = Object.assign(new Error('Wrapper error'), {
+      cause: innerErr,
+    });
+    const primary = nock(HOST)
+      .get(`${PATH}/${TYPE}`)
+      .replyWithError(wrapperErr);
+    const isGCE = await gcp.isAvailable();
+    await secondary;
+    primary.done();
+    assert.strictEqual(false, isGCE);
+  });
+
+  it('should fail on isAvailable if ENOTFOUND is wrapped inside an AggregateError or nested cause', async () => {
+    const secondary = secondaryHostRequest(500, 'ENOTFOUND');
+    const innerErr1 = Object.assign(new Error('ENOTFOUND'), {
+      code: 'ENOTFOUND',
+    });
+    const innerErr2 = Object.assign(new Error('EHOSTUNREACH'), {
+      code: 'EHOSTUNREACH',
+    });
+    const wrapperErr = Object.assign(new Error('Wrapper error'), {
+      cause: innerErr1,
+    });
+    const aggregateErr = new AggregateError(
+      [wrapperErr, innerErr2],
+      'Aggregate error',
+    );
+    const primary = nock(HOST)
+      .get(`${PATH}/${TYPE}`)
+      .replyWithError(aggregateErr);
+    const isGCE = await gcp.isAvailable();
+    await secondary;
+    primary.done();
+    assert.strictEqual(false, isGCE);
+  });
+
   it('should return first successful response', async () => {
     const secondary = secondaryHostRequest(500);
     const primary = nock(HOST).get(`${PATH}/${TYPE}`).reply(404);

From 66743aef33eb6b6f6b68edb6db646ec55c07aa8c Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Tue, 4 Aug 2026 17:05:03 +0000
Subject: [PATCH 06/15] feat(ci): add matrix sharding for unit test performance
 chore(ci): reduce unit-test output due to log truncation chore: run all ci
 tests

---
 .../calculate-shard-matrix/action.yaml        |  22 +++
 .../actions/check-shard-status/action.yaml    |  31 ++++
 .github/actions/run-unit-tests/action.yaml    |  33 +++++
 .github/workflows/presubmit.yaml              |  53 +++++--
 .github/workflows/windows-presubmit.yaml      |  50 +++++--
 ci/run_conditional_tests.sh                   | 133 +++++++++++++-----
 ci/run_single_test.sh                         |   6 +-
 7 files changed, 263 insertions(+), 65 deletions(-)
 create mode 100644 .github/actions/calculate-shard-matrix/action.yaml
 create mode 100644 .github/actions/check-shard-status/action.yaml
 create mode 100644 .github/actions/run-unit-tests/action.yaml

diff --git a/.github/actions/calculate-shard-matrix/action.yaml b/.github/actions/calculate-shard-matrix/action.yaml
new file mode 100644
index 000000000000..660e725ee84f
--- /dev/null
+++ b/.github/actions/calculate-shard-matrix/action.yaml
@@ -0,0 +1,22 @@
+name: "Calculate Shard Matrix"
+description: "Calculates the dynamic test shard matrix and shard total"
+outputs:
+  shard_matrix:
+    description: "JSON array of shard indices"
+    value: ${{ steps.set-matrix.outputs.shard_matrix }}
+  shard_total:
+    description: "Total number of shards"
+    value: ${{ steps.set-matrix.outputs.shard_total }}
+runs:
+  using: "composite"
+  steps:
+    - name: Calculate Matrix
+      id: set-matrix
+      shell: bash
+      env:
+        DRY_RUN_SHARDS: true
+        BUILD_TYPE: presubmit
+        TEST_TYPE: units
+        GIT_DIFF_ARG: "HEAD^1"
+      run: |
+        bash ci/run_conditional_tests.sh --strict
diff --git a/.github/actions/check-shard-status/action.yaml b/.github/actions/check-shard-status/action.yaml
new file mode 100644
index 000000000000..37f57a2992ae
--- /dev/null
+++ b/.github/actions/check-shard-status/action.yaml
@@ -0,0 +1,31 @@
+name: "Check Shard Status"
+description: "Checks if all unit test shards passed for a given Node version"
+inputs:
+  node-version:
+    required: true
+    description: "Node version to check"
+runs:
+  using: "composite"
+  steps:
+    - name: Check shard status
+      uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
+      with:
+        script: |
+          const { data: { jobs } } = await github.rest.actions.listJobsForWorkflowRun({
+            owner: context.repo.owner,
+            repo: context.repo.repo,
+            run_id: context.runId,
+          });
+          const nodeVersion = '${{ inputs.node-version }}';
+          const shardJobs = jobs.filter(j => j.name.includes(`units (Node ${nodeVersion},`));
+          if (shardJobs.length === 0) {
+            core.setFailed(`No shard jobs found for Node ${nodeVersion}`);
+            return;
+          }
+          const failed = shardJobs.filter(j => j.conclusion === 'failure' || j.conclusion === 'cancelled');
+          if (failed.length > 0) {
+            const failedLinks = failed.map(j => `- ${j.name}: ${j.html_url}`).join('\n');
+            core.setFailed(`${failed.length} shards failed for Node ${nodeVersion}:\n${failedLinks}`);
+          } else {
+            core.info(`All shards passed for Node ${nodeVersion}`);
+          }
diff --git a/.github/actions/run-unit-tests/action.yaml b/.github/actions/run-unit-tests/action.yaml
new file mode 100644
index 000000000000..69bf22693bdc
--- /dev/null
+++ b/.github/actions/run-unit-tests/action.yaml
@@ -0,0 +1,33 @@
+name: "Run Unit Test Shard"
+description: "Sets up Node.js, pnpm, and runs a unit test shard"
+inputs:
+  node-version:
+    required: true
+    description: "Node.js version to test"
+  shard-total:
+    required: true
+    description: "Total number of shards"
+  shard-index:
+    required: true
+    description: "0-based shard index"
+runs:
+  using: "composite"
+  steps:
+    - name: Use Node.js ${{ inputs.node-version }}
+      uses: actions/setup-node@249970729cb0ef3589644e2896645e5dc5ba9c38 # v6.5.0
+      with:
+        node-version: ${{ inputs.node-version }}
+    - uses: pnpm/action-setup@b906affcce14559ad1aafd4ab0e942779e9f58b1 # v4
+      with:
+        version: ^10.0.0
+    - run: node --version
+      shell: bash
+    - name: Run unit tests
+      shell: bash
+      run: bash ci/run_conditional_tests.sh --strict
+      env:
+        BUILD_TYPE: presubmit
+        TEST_TYPE: units
+        SHARD_TOTAL: ${{ inputs.shard-total }}
+        SHARD_INDEX: ${{ inputs.shard-index }}
+        GIT_DIFF_ARG: HEAD^1
diff --git a/.github/workflows/presubmit.yaml b/.github/workflows/presubmit.yaml
index c5de30eba54e..902233f76caa 100644
--- a/.github/workflows/presubmit.yaml
+++ b/.github/workflows/presubmit.yaml
@@ -5,29 +5,37 @@ on:
   pull_request:
 name: presubmit
 jobs:
+  setup:
+    runs-on: ubuntu-latest
+    outputs:
+      shard-matrix: ${{ steps.set-matrix.outputs.shard_matrix }}
+      shard-total: ${{ steps.set-matrix.outputs.shard_total }}
+    steps:
+      - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803 # v6.1.0
+        with:
+          fetch-depth: 2
+          persist-credentials: false
+      - id: set-matrix
+        uses: ./.github/actions/calculate-shard-matrix
   units:
+    needs: setup
+    name: units (Node ${{ matrix.node-version }}, Shard ${{ matrix.shard-index }})
     runs-on: ubuntu-latest
     strategy:
+      fail-fast: false
       matrix:
         node-version: [22, 24, 26]
+        shard-index: ${{ fromJSON(needs.setup.outputs.shard-matrix) }}
     steps:
       - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803 # v6.1.0
         with:
-          fetch-depth: 300
+          fetch-depth: 2
           persist-credentials: false
-      - name: Use Node.js ${{ matrix.node-version }}
-        uses: actions/setup-node@249970729cb0ef3589644e2896645e5dc5ba9c38 # v6.5.0
+      - uses: ./.github/actions/run-unit-tests
         with:
           node-version: ${{ matrix.node-version }}
-      - uses: pnpm/action-setup@b906affcce14559ad1aafd4ab0e942779e9f58b1 # v4
-        with:
-          version: ^10.0.0
-      - run: node --version
-      - run: ci/run_conditional_tests.sh
-        name: Run unit tests
-        env:
-          BUILD_TYPE: presubmit
-          TEST_TYPE: units
+          shard-total: ${{ needs.setup.outputs.shard-total }}
+          shard-index: ${{ matrix.shard-index }}
   lint:
     runs-on: ubuntu-latest
     continue-on-error: true
@@ -42,6 +50,25 @@ jobs:
           node-version: 24
       - run: npm install
       - run: node ./bin/linter.mjs --strict
-        name: Run monorepo linter
         env:
           GIT_DIFF_ARG: "HEAD^1"
+
+  # Dummy jobs to satisfy branch protection requirements for each node version
+  units-status:
+    name: units (${{ matrix.node-version }})
+    needs: units
+    runs-on: ubuntu-latest
+    if: always()
+    strategy:
+      fail-fast: false
+      matrix:
+        node-version: [22, 24, 26]
+    steps:
+      - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803 # v6.1.0
+        with:
+          persist-credentials: false
+      - name: Check shard status
+        uses: ./.github/actions/check-shard-status
+        with:
+          node-version: ${{ matrix.node-version }}
+>>>>>>> 657c33a5f3 (feat(ci): run unit-tests in parallel to speed them up)
diff --git a/.github/workflows/windows-presubmit.yaml b/.github/workflows/windows-presubmit.yaml
index 31105cfa46de..afd68aee344a 100644
--- a/.github/workflows/windows-presubmit.yaml
+++ b/.github/workflows/windows-presubmit.yaml
@@ -5,27 +5,53 @@ on:
   pull_request:
 name: presubmit-windows
 jobs:
+  setup:
+    runs-on: ubuntu-latest
+    outputs:
+      shard-matrix: ${{ steps.set-matrix.outputs.shard_matrix }}
+      shard-total: ${{ steps.set-matrix.outputs.shard_total }}
+    steps:
+      - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803 # v6.1.0
+        with:
+          fetch-depth: 2
+          persist-credentials: false
+      - id: set-matrix
+        uses: ./.github/actions/calculate-shard-matrix
   units:
+    needs: setup
+    name: units (Node ${{ matrix.node-version }}, Shard ${{ matrix.shard-index }})
     runs-on: windows-latest
     strategy:
+      fail-fast: false
       matrix:
         node-version: [22, 24, 26]
+        shard-index: ${{ fromJSON(needs.setup.outputs.shard-matrix) }}
     steps:
       - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803 # v6.1.0
         with:
-          fetch-depth: 300
+          fetch-depth: 2
           persist-credentials: false
-      - name: Use Node.js ${{ matrix.node-version }}
-        uses: actions/setup-node@249970729cb0ef3589644e2896645e5dc5ba9c38 # v6.5.0
+      - uses: ./.github/actions/run-unit-tests
         with:
           node-version: ${{ matrix.node-version }}
-      - uses: pnpm/action-setup@b906affcce14559ad1aafd4ab0e942779e9f58b1 # v4
+          shard-total: ${{ needs.setup.outputs.shard-total }}
+          shard-index: ${{ matrix.shard-index }}
+
+  # Dummy jobs to satisfy branch protection requirements for each node version
+  units-status:
+    name: units (${{ matrix.node-version }})
+    needs: units
+    runs-on: ubuntu-latest
+    if: always()
+    strategy:
+      fail-fast: false
+      matrix:
+        node-version: [22, 24, 26]
+    steps:
+      - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803 # v6.1.0
         with:
-          version: ^10.0.0
-      - run: node --version
-      - run: bash ci/run_conditional_tests.sh
-        name: Run windows unit tests
-        shell: bash
-        env:
-          BUILD_TYPE: presubmit
-          TEST_TYPE: units
+          persist-credentials: false
+      - name: Check shard status
+        uses: ./.github/actions/check-shard-status
+        with:
+          node-version: ${{ matrix.node-version }}
diff --git a/ci/run_conditional_tests.sh b/ci/run_conditional_tests.sh
index cb6ae744a087..29f42bf888b2 100755
--- a/ci/run_conditional_tests.sh
+++ b/ci/run_conditional_tests.sh
@@ -36,25 +36,50 @@ if [[ "$(node -v)" == v22* ]]; then
   export NODE_OPTIONS="${NODE_OPTIONS} --no-experimental-require-module"
 fi
 
-if [ ${BUILD_TYPE} == "presubmit" ]; then
-    # For presubmit build, we want to know the difference from the
-    # common commit in origin/main.
-    GIT_DIFF_ARG="origin/main..."
+for arg in "$@"; do
+    case "${arg}" in
+        --strict)
+            STRICT=true
+            ;;
+    esac
+done
 
-    # Then fetch enough history for finding the common commit.
-    git fetch origin main --deepen=300
+if [[ "${STRICT}" == "true" || "${STRICT}" == "1" ]]; then
+    if [ -z "${GIT_DIFF_ARG}" ]; then
+        echo "Error: STRICT mode requires GIT_DIFF_ARG to be set." >&2
+        exit 1
+    fi
+    set +e
+    git diff --quiet ${GIT_DIFF_ARG}
+    diff_status=$?
+    set -e
+    if [[ ${diff_status} -ne 0 && ${diff_status} -ne 1 ]]; then
+        echo "Error: STRICT mode git diff ${GIT_DIFF_ARG} failed with exit code ${diff_status}." >&2
+        exit 1
+    fi
+else
+    if [ -z "${GIT_DIFF_ARG}" ]; then
+        if [ "${BUILD_TYPE}" == "presubmit" ]; then
+            # For presubmit build, we want to know the difference from the
+            # common commit in origin/main.
+            GIT_DIFF_ARG="origin/main..."
 
-elif [ ${BUILD_TYPE} == "continuous" ]; then
-    # For continuous build, we want to know the difference in the last
-    # commit. This assumes we use squash commit when merging PRs.
-    GIT_DIFF_ARG="HEAD~.."
+            # Then fetch enough history for finding the common commit.
+            git fetch origin main --deepen=300
 
-    # Then fetch one last commit for getting the diff.
-    git fetch origin main --deepen=1
+        elif [ "${BUILD_TYPE}" == "continuous" ]; then
+            # For continuous build, we want to know the difference in the last
+            # commit. This assumes we use squash commit when merging PRs.
+            GIT_DIFF_ARG="HEAD~.."
 
-else
-    # Run everything.
-    GIT_DIFF_ARG=""
+            # Then fetch one last commit for getting the diff.
+            git fetch origin main --deepen=1
+
+        else
+            # Run everything.
+            GIT_DIFF_ARG=""
+        fi
+    fi
 fi
 
 # Then detect changes in the test scripts.
@@ -66,11 +91,10 @@ set -e
 if [[ "${changed}" -eq 0 ]]; then
     echo "no change detected in ci"
 else
-    echo "skipping trigger of tests for now: tracking in #7540"
-    # echo "change detected in ci, we should test everything"
-    # echo "result of git diff ${GIT_DIFF_ARG} ci:"
-    # git diff ${GIT_DIFF_ARG} ci
-    # GIT_DIFF_ARG=""
+    echo "change detected in ci, we should test everything"
+    echo "result of git diff ${GIT_DIFF_ARG} ci:"
+    git diff ${GIT_DIFF_ARG} ci
+    GIT_DIFF_ARG=""
 fi
 
 # Now we have a fixed list, but we can change it to autodetect if
@@ -87,7 +111,7 @@ subdirs=(
 )
 
 RETVAL=0
-# These following APIs need an explicit credential file to run properly (or oAuth2, which we don't support in this repo). 
+# These following APIs need an explicit credential file to run properly (or oAuth2, which we don't support in this repo).
 # When we hit these packages, we will run the "samples with credentials" trigger, which contains the credentials as an env variable
 
 tests_with_credentials="core/packages/google-auth-library-nodejs/ packages/google-analytics-admin/ packages/google-area120-tables/ packages/google-analytics-data/ packages/google-iam-credentials/ packages/google-apps-meet/ packages/google-chat/ packages/google-streetview-publish/ packages/google-cloud-developerconnect/"
@@ -95,10 +119,13 @@ tests_with_credentials="core/packages/google-auth-library-nodejs/ packages/googl
 # Some packages are only used by our bots and automation. These packages do not need to run on Windows and
 # often employ platform specific code like file system interaction. Some packages may also fail
 # on Windows due to incompatible npm scripts.
-# 
+#
 # Until these packages can be updated to be OS agnostic, we will skip them on Windows.
 windows_exempt_tests="core/ core/packages/ core/dev-packages/ .github/scripts/fixtures/ .github/scripts/tests/ core/packages/gapic-node-processing/ core/packages/typeless-sample-bot/ handwritten/cloud-profiler/"
 
+# Gather all test directories into an array
+test_dirs=()
+
 for subdir in ${subdirs[@]}; do
     for d in `ls -d ${subdir}/*/`; do
         if [ -s "ignore.json" ] && jq -e ".ignored[] | select(. == \"$d\")" ignore.json > /dev/null 2>&1; then
@@ -121,7 +148,7 @@ for subdir in ${subdirs[@]}; do
         # System tests for packages are broken and blocking PRs.
         # See https://github.com/googleapis/google-cloud-node/issues/7976.
         #
-        # Per https://github.com/googleapis/google-cloud-node/issues/7921, 
+        # Per https://github.com/googleapis/google-cloud-node/issues/7921,
         # we are likely to permanently remove these tests in the near future.
         if [[ "${subdir}" == "packages" && "${TEST_TYPE}" == "system" ]]; then
             echo "Skipping ${TEST_TYPE} test for packages: ${d}"
@@ -131,7 +158,7 @@ for subdir in ${subdirs[@]}; do
         # Sample tests for packages are broken/flaky and blocking PRs.
         # See https://github.com/googleapis/google-cloud-node/issues/7976#issuecomment-4210458096.
         #
-        # Per https://github.com/googleapis/google-cloud-node/issues/7921, 
+        # Per https://github.com/googleapis/google-cloud-node/issues/7921,
         # we are likely to permanently remove these tests in the near future.
         if [[ "${subdir}" == "packages" && "${TEST_TYPE}" == "samples" ]]; then
             echo "Skipping ${TEST_TYPE} test for packages: ${d}"
@@ -209,21 +236,51 @@ for subdir in ${subdirs[@]}; do
             fi
         fi
         if [ "${should_test}" = true ]; then
-            echo "running test in ${d}"
-            pushd ${d}
-            # Temporarily allow failure.
-            set +e
-            ${test_script}
-            ret=$?
-            set -e
-            if [ ${ret} -ne 0 ]; then
-                RETVAL=${ret}
-                # Since there are so many APIs, we should exit early if there's an error
-                exit ${RETVAL}
-            fi
-            popd
+            test_dirs+=("${d}")
         fi
     done
 done
+# If DRY_RUN_SHARDS is set, output dynamic matrix values to GitHub Actions and exit
+if [[ "${DRY_RUN_SHARDS}" == "true" ]]; then
+    count=${#test_dirs[@]}
+    if [[ $count -gt 15 ]]; then
+        matrix="[0, 1, 2, 3, 4]"
+        total="5"
+    else
+        matrix="[0]"
+        total="1"
+    fi
+    if [[ -n "${GITHUB_OUTPUT}" ]]; then
+        echo "shard_matrix=${matrix}" >> "${GITHUB_OUTPUT}"
+        echo "shard_total=${total}" >> "${GITHUB_OUTPUT}"
+    else
+        echo "shard_matrix=${matrix}"
+        echo "shard_total=${total}"
+    fi
+    exit 0
+fi
+
+# If SHARD_TOTAL and SHARD_INDEX are provided, we will only run a subset of the tests.
+for i in "${!test_dirs[@]}"; do
+    d="${test_dirs[$i]}"
+
+    if [[ -n "${SHARD_TOTAL}" && -n "${SHARD_INDEX}" ]]; then
+        if (( SHARD_TOTAL > 0 && i % SHARD_TOTAL != SHARD_INDEX )); then
+            continue
+        fi
+    fi
+
+    echo "running test in ${d}"
+    pushd "${d}" >/dev/null
+    # Temporarily allow failure.
+    set +e
+    "${test_script}"
+    ret=$?
+    set -e
+    if [ ${ret} -ne 0 ]; then
+        exit ${ret}
+    fi
+    popd >/dev/null
+done
 
-exit ${RETVAL}
+exit 0
diff --git a/ci/run_single_test.sh b/ci/run_single_test.sh
index 662a1184f347..3dfd98ee7a2b 100755
--- a/ci/run_single_test.sh
+++ b/ci/run_single_test.sh
@@ -37,6 +37,8 @@ if [ ${BUILD_TYPE} != "presubmit" ]; then
     export MOCHA_REPORTER_OUTPUT=${PROJECT}_sponge_log.xml
     export MOCHA_REPORTER_SUITENAME=${PROJECT}
     export MOCHA_REPORTER=xunit
+else
+    export MOCHA_REPORTER=dot
 fi
 
 # Install dependencies
@@ -47,8 +49,8 @@ if command -v cygpath >/dev/null 2>&1; then
     PNPMFILE_PATH=$(cygpath -m "${PNPMFILE_PATH}")
 fi
 
-echo "pnpm install --ignore-scripts --engine-strict --prod --pnpmfile \"${PNPMFILE_PATH}\"; pnpm install --pnpmfile \"${PNPMFILE_PATH}\""
-pnpm install --ignore-scripts --engine-strict --prod --pnpmfile "${PNPMFILE_PATH}"; pnpm install --pnpmfile "${PNPMFILE_PATH}"
+echo "pnpm install --engine-strict --pnpmfile \"${PNPMFILE_PATH}\""
+pnpm install --engine-strict --pnpmfile "${PNPMFILE_PATH}"
 
 
 retval=0

From 491aba81bfa87556e9f022359d28b3093b1b655e Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Tue, 4 Aug 2026 17:05:32 +0000
Subject: [PATCH 07/15] core test fixes

---
 .../pack-n-play/test/fixtures/esm-package/test/test.js       | 3 ++-
 .../pack-n-play/test/fixtures/leaky/test/test.ts             | 3 ++-
 .../dev-packages/pack-n-play/test/fixtures/pass/test/test.ts | 3 ++-
 core/dev-packages/pack-n-play/test/test.ts                   | 5 +++--
 4 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js b/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
index 037babedf227..2adbf53d289c 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
+++ b/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
@@ -16,7 +16,8 @@ import {packNTest} from 'pack-n-play';
 import * as assert from 'assert';
 import {describe, it} from 'mocha';
 
-describe('ESM package', () => {
+describe('ESM package', function () {
+  this.timeout(120000);
   it('should support esm property', () =>
     packNTest({
       sample: {
diff --git a/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts b/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
index 3a9dc7f39b39..9c56bc9c0741 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
+++ b/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
@@ -16,7 +16,8 @@ import {packNTest} from 'pack-n-play';
 import * as assert from 'assert';
 import {describe, it} from 'mocha';
 
-describe('leaky tests', () => {
+describe('leaky tests', function () {
+  this.timeout(120000);
   it('should fail packing n testing', async () => {
     await assert.rejects(
       packNTest({
diff --git a/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts b/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
index 2dd02fb27cff..50d0d07d620d 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
+++ b/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
@@ -15,7 +15,8 @@
 import {packNTest} from 'pack-n-play';
 import {describe, it} from 'mocha';
 
-describe('passing tests', () => {
+describe('passing tests', function () {
+  this.timeout(120000);
   it('should pass the test', async () => {
     await packNTest({
       sample: {
diff --git a/core/dev-packages/pack-n-play/test/test.ts b/core/dev-packages/pack-n-play/test/test.ts
index da954b94ba08..06aef544b4e7 100644
--- a/core/dev-packages/pack-n-play/test/test.ts
+++ b/core/dev-packages/pack-n-play/test/test.ts
@@ -18,7 +18,8 @@ import execa = require('execa');
 import {describe, it} from 'mocha';
 
 describe('pack-n-play', () => {
-  it('should run tests', async () => {
+  it('should run tests', async function () {
+    this.timeout(600000); // 10 minutes
     const fixturesPath = path.resolve('./test/fixtures');
     const dirs = fs
       .readdirSync(fixturesPath)
@@ -29,7 +30,7 @@ describe('pack-n-play', () => {
         stdio: 'inherit',
         cwd: dir,
       };
-      await execa('npm', ['install'], opts);
+      await execa('npm', ['install', '--no-audit', '--no-fund'], opts);
       await execa('npm', ['link', '../../../'], opts);
       await execa('npm', ['test'], opts);
     }

From 4339fd166f94196a0ce8d2fb373a8d1406d4be76 Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Wed, 5 Aug 2026 12:02:07 +0000
Subject: [PATCH 08/15] revert unnecessary addition of port

---
 core/packages/nodejs-googleapis-common/test/test.discovery.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/core/packages/nodejs-googleapis-common/test/test.discovery.ts b/core/packages/nodejs-googleapis-common/test/test.discovery.ts
index 6745982a218f..0e656c5fb6b1 100644
--- a/core/packages/nodejs-googleapis-common/test/test.discovery.ts
+++ b/core/packages/nodejs-googleapis-common/test/test.discovery.ts
@@ -24,7 +24,7 @@ describe(__filename, () => {
     nock.cleanAll();
   });
   it('should discover an API', async () => {
-    const discoUrl = 'http://test.local:80';
+    const discoUrl = 'http://test.local';
     const scope = nock(discoUrl)
       .get('/')
       .replyWithFile(200, './test/fixtures/compute-v1.json', {
@@ -37,7 +37,7 @@ describe(__filename, () => {
     scope.done();
   });
   it('should discover an API through second weird path', async () => {
-    const discoUrl = 'http://test.local:80';
+    const discoUrl = 'http://test.local';
     const scope = nock(discoUrl)
       .get('/')
       .replyWithFile(200, './test/fixtures/compute-v1.json', {

From dc343c6dcaaf68d089d3a6c9b5862e4d389bc07b Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Wed, 5 Aug 2026 12:03:42 +0000
Subject: [PATCH 09/15] Revert "core test fixes"

This reverts commit 491aba81bfa87556e9f022359d28b3093b1b655e.
---
 .../pack-n-play/test/fixtures/esm-package/test/test.js       | 3 +--
 .../pack-n-play/test/fixtures/leaky/test/test.ts             | 3 +--
 .../dev-packages/pack-n-play/test/fixtures/pass/test/test.ts | 3 +--
 core/dev-packages/pack-n-play/test/test.ts                   | 5 ++---
 4 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js b/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
index 2adbf53d289c..037babedf227 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
+++ b/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
@@ -16,8 +16,7 @@ import {packNTest} from 'pack-n-play';
 import * as assert from 'assert';
 import {describe, it} from 'mocha';
 
-describe('ESM package', function () {
-  this.timeout(120000);
+describe('ESM package', () => {
   it('should support esm property', () =>
     packNTest({
       sample: {
diff --git a/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts b/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
index 9c56bc9c0741..3a9dc7f39b39 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
+++ b/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
@@ -16,8 +16,7 @@ import {packNTest} from 'pack-n-play';
 import * as assert from 'assert';
 import {describe, it} from 'mocha';
 
-describe('leaky tests', function () {
-  this.timeout(120000);
+describe('leaky tests', () => {
   it('should fail packing n testing', async () => {
     await assert.rejects(
       packNTest({
diff --git a/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts b/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
index 50d0d07d620d..2dd02fb27cff 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
+++ b/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
@@ -15,8 +15,7 @@
 import {packNTest} from 'pack-n-play';
 import {describe, it} from 'mocha';
 
-describe('passing tests', function () {
-  this.timeout(120000);
+describe('passing tests', () => {
   it('should pass the test', async () => {
     await packNTest({
       sample: {
diff --git a/core/dev-packages/pack-n-play/test/test.ts b/core/dev-packages/pack-n-play/test/test.ts
index 06aef544b4e7..da954b94ba08 100644
--- a/core/dev-packages/pack-n-play/test/test.ts
+++ b/core/dev-packages/pack-n-play/test/test.ts
@@ -18,8 +18,7 @@ import execa = require('execa');
 import {describe, it} from 'mocha';
 
 describe('pack-n-play', () => {
-  it('should run tests', async function () {
-    this.timeout(600000); // 10 minutes
+  it('should run tests', async () => {
     const fixturesPath = path.resolve('./test/fixtures');
     const dirs = fs
       .readdirSync(fixturesPath)
@@ -30,7 +29,7 @@ describe('pack-n-play', () => {
         stdio: 'inherit',
         cwd: dir,
       };
-      await execa('npm', ['install', '--no-audit', '--no-fund'], opts);
+      await execa('npm', ['install'], opts);
       await execa('npm', ['link', '../../../'], opts);
       await execa('npm', ['test'], opts);
     }

From d5aeba8d8aedbf23ae2c2ec4153c21c06b840bb1 Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Fri, 7 Aug 2026 17:16:56 +0000
Subject: [PATCH 10/15] fix regressions from recent PRs

---
 .pnpmfile.cjs         | 25 +++++++++++++++++++++++++
 ci/run_single_test.sh | 11 +++++++++--
 2 files changed, 34 insertions(+), 2 deletions(-)
 create mode 100644 .pnpmfile.cjs

diff --git a/.pnpmfile.cjs b/.pnpmfile.cjs
new file mode 100644
index 000000000000..8229d2f1fa80
--- /dev/null
+++ b/.pnpmfile.cjs
@@ -0,0 +1,25 @@
+module.exports = {
+  hooks: {
+    readPackage(pkg, context) {
+      // Override yargs for Node >= 24 to prevent ESM scope require errors
+      if (pkg.dependencies && pkg.dependencies.yargs) {
+        mutateYargs(pkg.dependencies, pkg.name, 'dependencies', context);
+      }
+      if (pkg.devDependencies && pkg.devDependencies.yargs) {
+        mutateYargs(pkg.devDependencies, pkg.name, 'devDependencies', context);
+      }
+      return pkg;
+    }
+  }
+};
+
+function mutateYargs(deps, pkgName, depType, context) {
+  const nodeVersion = process.version;
+  const majorVersion = parseInt(nodeVersion.replace('v', '').split('.')[0], 10);
+  
+  if (majorVersion >= 24) {
+    console.log(`[pnpmfile] Node.js version is ${nodeVersion} (>= 24). Overriding yargs to 18.0.0 in ${pkgName}`);
+    deps.yargs = '18.0.0';
+  }
+}
+
diff --git a/ci/run_single_test.sh b/ci/run_single_test.sh
index ccb32c6d6d80..3dfd98ee7a2b 100755
--- a/ci/run_single_test.sh
+++ b/ci/run_single_test.sh
@@ -42,8 +42,15 @@ else
 fi
 
 # Install dependencies
-echo "pnpm install --ignore-scripts --engine-strict --prod; pnpm install"
-pnpm install --ignore-scripts --engine-strict --prod; pnpm install
+# Normalize POSIX paths to Windows-compatible mixed paths (forward slashes) on Windows Git Bash
+# so native Node.js and pnpm processes can resolve .pnpmfile.cjs without segmentation faults.
+PNPMFILE_PATH="${PROJECT_ROOT}/.pnpmfile.cjs"
+if command -v cygpath >/dev/null 2>&1; then
+    PNPMFILE_PATH=$(cygpath -m "${PNPMFILE_PATH}")
+fi
+
+echo "pnpm install --engine-strict --pnpmfile \"${PNPMFILE_PATH}\""
+pnpm install --engine-strict --pnpmfile "${PNPMFILE_PATH}"
 
 
 retval=0

From 40133a284664958968271cdc4a4d85c77695ee4d Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Fri, 7 Aug 2026 18:31:23 +0000
Subject: [PATCH 11/15] attempt to fix bigtable unit tests

---
 .../test/metrics-collector/version/get-version-script.js     | 5 ++++-
 .../bigtable/test/metrics-collector/version/version.ts       | 3 ++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/handwritten/bigtable/test/metrics-collector/version/get-version-script.js b/handwritten/bigtable/test/metrics-collector/version/get-version-script.js
index 2950deaca99f..a7261a04c187 100644
--- a/handwritten/bigtable/test/metrics-collector/version/get-version-script.js
+++ b/handwritten/bigtable/test/metrics-collector/version/get-version-script.js
@@ -60,7 +60,10 @@ async function main() {
   const packageJSON = fs.readFileSync(packagePath);
   const expectedVersion = JSON.parse(packageJSON.toString()).version;
 
-  const fakeBigtable = new Bigtable();
+  const fakeBigtable = new Bigtable({
+    projectId: 'projectId',
+    credentials: {client_email: 'bogus', private_key: 'bogus'},
+  });
   const testMetricsHandler = new TestMetricsHandlerKeepName();
   fakeBigtable._metricsConfigManager = new ClientSideMetricsConfigManager([
     testMetricsHandler,
diff --git a/handwritten/bigtable/test/metrics-collector/version/version.ts b/handwritten/bigtable/test/metrics-collector/version/version.ts
index 06bf9d61a1db..3ee129170055 100644
--- a/handwritten/bigtable/test/metrics-collector/version/version.ts
+++ b/handwritten/bigtable/test/metrics-collector/version/version.ts
@@ -17,7 +17,8 @@ import {describe} from 'mocha';
 import {execSync} from 'node:child_process';
 
 describe('Bigtable/CSMVersion', () => {
-  it('Fetches the right client side metrics version', async () => {
+  it('Fetches the right client side metrics version', function () {
+    this.timeout(30000);
     execSync('cd test/metrics-collector/version && node get-version-script');
   });
 });

From 5259b8fd9fe6fc84d973db3e741e5835c906e2ee Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Mon, 10 Aug 2026 16:58:18 +0000
Subject: [PATCH 12/15] increase timeouts for pack-n-play

---
 .../pack-n-play/test/fixtures/esm-package/test/test.js          | 2 +-
 core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts  | 2 +-
 core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts   | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js b/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
index 2adbf53d289c..7d01aeaae791 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
+++ b/core/dev-packages/pack-n-play/test/fixtures/esm-package/test/test.js
@@ -17,7 +17,7 @@ import * as assert from 'assert';
 import {describe, it} from 'mocha';
 
 describe('ESM package', function () {
-  this.timeout(120000);
+  this.timeout(300000);
   it('should support esm property', () =>
     packNTest({
       sample: {
diff --git a/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts b/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
index 9c56bc9c0741..6e8f7ffe17c3 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
+++ b/core/dev-packages/pack-n-play/test/fixtures/leaky/test/test.ts
@@ -17,7 +17,7 @@ import * as assert from 'assert';
 import {describe, it} from 'mocha';
 
 describe('leaky tests', function () {
-  this.timeout(120000);
+  this.timeout(300000);
   it('should fail packing n testing', async () => {
     await assert.rejects(
       packNTest({
diff --git a/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts b/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
index 50d0d07d620d..d2ff7417372d 100644
--- a/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
+++ b/core/dev-packages/pack-n-play/test/fixtures/pass/test/test.ts
@@ -16,7 +16,7 @@ import {packNTest} from 'pack-n-play';
 import {describe, it} from 'mocha';
 
 describe('passing tests', function () {
-  this.timeout(120000);
+  this.timeout(300000);
   it('should pass the test', async () => {
     await packNTest({
       sample: {

From ff669479d0897d06daedd124df09d2f0f083dd77 Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Tue, 11 Aug 2026 14:28:06 -0700
Subject: [PATCH 13/15] Apply suggestion from @bshaffer

---
 .github/actions/check-shard-status/action.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/actions/check-shard-status/action.yaml b/.github/actions/check-shard-status/action.yaml
index 37f57a2992ae..a3bc51f3abc0 100644
--- a/.github/actions/check-shard-status/action.yaml
+++ b/.github/actions/check-shard-status/action.yaml
@@ -22,7 +22,7 @@ runs:
             core.setFailed(`No shard jobs found for Node ${nodeVersion}`);
             return;
           }
-          const failed = shardJobs.filter(j => j.conclusion === 'failure' || j.conclusion === 'cancelled');
+          const failed = shardJobs.filter(j => j.conclusion !== 'success');
           if (failed.length > 0) {
             const failedLinks = failed.map(j => `- ${j.name}: ${j.html_url}`).join('\n');
             core.setFailed(`${failed.length} shards failed for Node ${nodeVersion}:\n${failedLinks}`);

From 646734e2504ca8dad1b620ae219ae5117119e612 Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Tue, 11 Aug 2026 14:35:35 -0700
Subject: [PATCH 14/15] Apply suggestion from @bshaffer

---
 .github/workflows/presubmit.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/presubmit.yaml b/.github/workflows/presubmit.yaml
index ba2c8ce7af07..7788f5c35df8 100644
--- a/.github/workflows/presubmit.yaml
+++ b/.github/workflows/presubmit.yaml
@@ -52,7 +52,7 @@ jobs:
       - run: npm run lint
         name: Run monorepo linter
 
-  # Dummy jobs to satisfy branch protection requirements for each node version
+  # Consolidate shards into jobs representing aggregate status to simplify branch protection requirements
   units-status:
     name: units (${{ matrix.node-version }})
     needs: units

From 3234034a5783e8b4f334b57b9d23aa5548b1c4e0 Mon Sep 17 00:00:00 2001
From: Brent Shaffer <betterbrent@google.com>
Date: Tue, 11 Aug 2026 22:41:10 +0000
Subject: [PATCH 15/15] change DRY_RUN_SHARD to RUN_TESTS_MDOE and fix merge

---
 .../calculate-shard-matrix/action.yaml        |  2 +-
 .github/actions/run-unit-tests/action.yaml    |  1 +
 ci/run_conditional_tests.sh                   | 22 +++++++++++++++++--
 .../test/metrics-collector/version/version.ts |  2 +-
 4 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/.github/actions/calculate-shard-matrix/action.yaml b/.github/actions/calculate-shard-matrix/action.yaml
index 660e725ee84f..51e8e5c78ece 100644
--- a/.github/actions/calculate-shard-matrix/action.yaml
+++ b/.github/actions/calculate-shard-matrix/action.yaml
@@ -14,7 +14,7 @@ runs:
       id: set-matrix
       shell: bash
       env:
-        DRY_RUN_SHARDS: true
+        RUN_TESTS_MODE: CALCULATE_SHARD_MATRIX
         BUILD_TYPE: presubmit
         TEST_TYPE: units
         GIT_DIFF_ARG: "HEAD^1"
diff --git a/.github/actions/run-unit-tests/action.yaml b/.github/actions/run-unit-tests/action.yaml
index 69bf22693bdc..61aa5b9b4f15 100644
--- a/.github/actions/run-unit-tests/action.yaml
+++ b/.github/actions/run-unit-tests/action.yaml
@@ -26,6 +26,7 @@ runs:
       shell: bash
       run: bash ci/run_conditional_tests.sh --strict
       env:
+        RUN_TESTS_MODE: RUN_UNIT_TESTS
         BUILD_TYPE: presubmit
         TEST_TYPE: units
         SHARD_TOTAL: ${{ inputs.shard-total }}
diff --git a/ci/run_conditional_tests.sh b/ci/run_conditional_tests.sh
index 29f42bf888b2..e42d0f82bdc5 100755
--- a/ci/run_conditional_tests.sh
+++ b/ci/run_conditional_tests.sh
@@ -49,6 +49,10 @@ if [[ "${STRICT}" == "true" || "${STRICT}" == "1" ]]; then
         echo "Error: STRICT mode requires GIT_DIFF_ARG to be set." >&2
         exit 1
     fi
+    if [[ -z "${RUN_TESTS_MODE}" ]]; then
+        echo "Error: STRICT mode requires RUN_TESTS_MODE to be set." >&2
+        exit 1
+    fi
     set +e
     git diff --quiet ${GIT_DIFF_ARG}
     diff_status=$?
@@ -82,6 +86,20 @@ else
     fi
 fi
 
+if [[ -n "${RUN_TESTS_MODE}" ]]; then
+    if [[ "${RUN_TESTS_MODE}" != "CALCULATE_SHARD_MATRIX" && "${RUN_TESTS_MODE}" != "RUN_UNIT_TESTS" ]]; then
+        echo "Error: RUN_TESTS_MODE must be either CALCULATE_SHARD_MATRIX or RUN_UNIT_TESTS." >&2
+        exit 1
+    fi
+fi
+
+if [[ "${RUN_TESTS_MODE}" == "RUN_UNIT_TESTS" ]]; then
+    if [[ -z "${SHARD_TOTAL}" || -z "${SHARD_INDEX}" ]]; then
+        echo "Error: SHARD_TOTAL and SHARD_INDEX must be set when RUN_TESTS_MODE is RUN_UNIT_TESTS." >&2
+        exit 1
+    fi
+fi
+
 # Then detect changes in the test scripts.
 
 set +e
@@ -240,8 +258,8 @@ for subdir in ${subdirs[@]}; do
         fi
     done
 done
-# If DRY_RUN_SHARDS is set, output dynamic matrix values to GitHub Actions and exit
-if [[ "${DRY_RUN_SHARDS}" == "true" ]]; then
+# If RUN_TESTS_MODE is CALCULATE_SHARD_MATRIX, output dynamic matrix values to GitHub Actions and exit
+if [[ "${RUN_TESTS_MODE}" == "CALCULATE_SHARD_MATRIX" ]]; then
     count=${#test_dirs[@]}
     if [[ $count -gt 15 ]]; then
         matrix="[0, 1, 2, 3, 4]"
diff --git a/handwritten/bigtable/test/metrics-collector/version/version.ts b/handwritten/bigtable/test/metrics-collector/version/version.ts
index 36107a7dbc6a..bbf32d5c234e 100644
--- a/handwritten/bigtable/test/metrics-collector/version/version.ts
+++ b/handwritten/bigtable/test/metrics-collector/version/version.ts
@@ -17,7 +17,7 @@ import {describe} from 'mocha';
 import {execSync} from 'node:child_process';
 
 describe('Bigtable/CSMVersion', () => {
-  it.skip('Fetches the right client side metrics version', async () => {
+  it.skip('Fetches the right client side metrics version', async function () {
     this.timeout(30000);
     execSync('cd test/metrics-collector/version && node get-version-script');
   });