fix(shard): fail when no tests match across all shards

packages/playwright/src/runner/loadUtils.ts

@@ -155,6 +155,7 @@ export async function createRootSuite(testRun: TestRun, errors: TestError[], sho
       rootSuite._addSuite(buildProjectSuite(project, filteredProjectSuites.get(project)!));
     }
   }
+  testRun.testCountBeforeSharding = rootSuite.allTests().length;
 
   // Complain about only.
   if (config.config.forbidOnly) {

packages/playwright/src/runner/tasks.ts

@@ -91,6 +91,7 @@ export class TestRun {
   topLevelProjects: commonConfig.FullProjectInternal[] = [];
   hasWorkerErrors = false;
   failedTestCount = 0;
+  testCountBeforeSharding = 0;
   readonly loadFileFilters: Matcher[] = [];
   readonly preOnlyTestFilters: TestCaseFilter[] = [];
   readonly postShardTestFilters: TestCaseFilter[] = [];
@@ -335,9 +336,10 @@ export function createLoadTask(mode: 'out-of-process' | 'in-process', options: {
 
       await createRootSuite(testRun, options.failOnLoadErrors ? errors : softErrors, !!options.filterOnly);
       // Fail when no tests.
-      if (options.failOnLoadErrors && !testRun.rootSuite?.allTests().length
+      const testCount = testRun.config.config.shard ? testRun.testCountBeforeSharding : testRun.rootSuite?.allTests().length;
+      if (options.failOnLoadErrors && !testCount
           && !testRun.options.passWithNoTests
-          && !testRun.config.config.shard && !testRun.options.onlyChanged
+          && !testRun.options.onlyChanged
           && !testRun.options.testList && !testRun.options.testListInvert) {
         if (testRun.options.locations?.length) {
           throw new Error([

tests/playwright-test/reporter-preprocess.spec.ts

@@ -369,6 +369,30 @@ test('skipSharding disables the built-in shard filter; preprocess sees the full
   expect(result.outputLines).toContain('begin: t0,t2');
 });
 
+test('custom sharding may produce an empty shard', async ({ runInlineTest }) => {
+  const result = await runInlineTest({
+    'reporter.ts': `
+      class R {
+        async preprocess({ suite, testRun }) {
+          testRun.skipSharding();
+          for (const t of suite.allTests())
+            testRun.exclude(t);
+        }
+      }
+      module.exports = R;
+    `,
+    'playwright.config.ts': `module.exports = { reporter: './reporter.ts', shard: { current: 2, total: 2 } };`,
+    'a.test.ts': `
+      import { test } from '@playwright/test';
+      test('t0', async () => {});
+    `,
+  }, { reporter: '', workers: 1 });
+
+  expect(result.exitCode).toBe(0);
+  expect(result.passed).toBe(0);
+  expect(result.output).not.toContain('No tests found');
+});
+
 test('multiple reporters declaring custom sharding throws', async ({ runInlineTest }) => {
   const result = await runInlineTest({
     'reporter-a.ts': `

tests/playwright-test/shard.spec.ts

@@ -156,6 +156,25 @@ test('should not produce skipped tests for zero-sized shards', async ({ runInlin
   expect(result.outputLines).toEqual([]);
 });
 
+test('should fail when no tests match across all shards', async ({ runInlineTest }) => {
+  const result = await runInlineTest(tests, { shard: '1/2', grep: 'does-not-match' });
+  expect(result.exitCode).toBe(1);
+  expect(result.output).toContain('No tests found');
+});
+
+test('should fail when no test files match across all shards', async ({ runInlineTest }) => {
+  const result = await runInlineTest(tests, { shard: '1/2' }, {}, { additionalArgs: ['does-not-match'] });
+  expect(result.exitCode).toBe(1);
+  expect(result.output).toContain('No tests found');
+  expect(result.output).toContain('Make sure that arguments are regular expressions matching test files');
+});
+
+test('should pass with no tests across all shards and --pass-with-no-tests', async ({ runInlineTest }) => {
+  const result = await runInlineTest(tests, { 'shard': '1/2', 'grep': 'does-not-match', 'pass-with-no-tests': true });
+  expect(result.exitCode).toBe(0);
+  expect(result.passed).toBe(0);
+});
+
 test('should respect shard=1/2 in config', async ({ runInlineTest }) => {
   const result = await runInlineTest({
     ...tests,