feat(test runner): expose FullConfig.actualWorkers

This property is used by reporters, so stop plumbing it through metadata.

docs/src/test-api/class-fullconfig.md

@@ -4,6 +4,14 @@
 
 Resolved configuration which is accessible via [`property: TestInfo.config`] and is passed to the test reporters. To see the format of Playwright configuration file, please see [TestConfig] instead.
 
+## property: FullConfig.actualWorkers
+* since: v1.46
+- type: <[int]>
+
+The actual number of worker processes used for running tests. This number depends on the maximum number of workers specified in [`property: TestConfig.workers`], the list of running tests and their mode of parallel or sequential execution.
+
+This property is only available after tests have started running.
+
 ## property: FullConfig.configFile
 * since: v1.20
 - type: ?<[string]>

packages/playwright/src/common/config.ts

@@ -70,6 +70,7 @@ export class FullConfigInternal {
     this.plugins = (privateConfiguration?.plugins || []).map((p: any) => ({ factory: p }));
 
     this.config = {
+      actualWorkers: 0,
       configFile: resolvedConfigFile,
       rootDir: pathResolve(configDir, userConfig.testDir) || configDir,
       forbidOnly: takeFirst(configCLIOverrides.forbidOnly, userConfig.forbidOnly, false),
@@ -134,6 +135,10 @@ export class FullConfigInternal {
     this.config.projects = this.projects.map(p => p.project);
   }
 
+  setActualWorkers(actualWorkers: number) {
+    this.config.actualWorkers = actualWorkers;
+  }
+
   private _assignUniqueProjectIds(projects: FullProjectInternal[]) {
     const usedNames = new Set();
     for (const p of projects) {

packages/playwright/src/common/configLoader.ts

@@ -89,6 +89,7 @@ export async function deserializeConfig(data: SerializedConfig): Promise<FullCon
     addToCompilationCache(data.compilationCache);
 
   const config = await loadConfig(data.location, data.configCLIOverrides);
+  config.setActualWorkers(data.actualWorkers);
   await initializeEsmLoader();
   return config;
 }

packages/playwright/src/common/ipc.ts

@@ -43,6 +43,8 @@ export type ConfigCLIOverrides = {
 export type SerializedConfig = {
   location: ConfigLocation;
   configCLIOverrides: ConfigCLIOverrides;
+  // TODO: create a struct to hold this and more properties like cliProjectFilter.
+  actualWorkers: number;
   compilationCache?: SerializedCompilationCache;
 };
 
@@ -131,6 +133,7 @@ export function serializeConfig(config: FullConfigInternal, passCompilationCache
   const result: SerializedConfig = {
     location: { configDir: config.configDir, resolvedConfigFile: config.config.configFile },
     configCLIOverrides: config.configCLIOverrides,
+    actualWorkers: config.config.actualWorkers,
     compilationCache: passCompilationCache ? serializeCompilationCache() : undefined,
   };
   return result;

packages/playwright/src/isomorphic/teleReceiver.ts

@@ -29,6 +29,7 @@ export type JsonStackFrame = { file: string, line: number, column: number };
 export type JsonStdIOType = 'stdout' | 'stderr';
 
 export type JsonConfig = Pick<reporterTypes.FullConfig, 'configFile' | 'globalTimeout' | 'maxFailures' | 'metadata' | 'rootDir' | 'version' | 'workers'>;
+export type JsonBeginParams = { actualWorkers: number };
 
 export type JsonPattern = {
   s?: string;
@@ -162,7 +163,7 @@ export class TeleReporterReceiver {
       return;
     }
     if (method === 'onBegin') {
-      this._onBegin();
+      this._onBegin(params);
       return;
     }
     if (method === 'onTestBegin') {
@@ -213,7 +214,8 @@ export class TeleReporterReceiver {
       this._mergeSuiteInto(suite, projectSuite);
   }
 
-  private _onBegin() {
+  private _onBegin(params: JsonBeginParams) {
+    this._config.actualWorkers = params.actualWorkers;
     this._reporter.onBegin?.(this._rootSuite);
   }
 
@@ -578,6 +580,7 @@ export class TeleTestResult implements reporterTypes.TestResult {
 export type TeleFullProject = reporterTypes.FullProject;
 
 export const baseFullConfig: reporterTypes.FullConfig = {
+  actualWorkers: 0,
   forbidOnly: false,
   fullyParallel: false,
   globalSetup: null,

packages/playwright/src/reporters/base.ts

@@ -168,7 +168,7 @@ export class BaseReporter implements ReporterV2 {
   }
 
   protected generateStartingMessage() {
-    const jobs = this.config.metadata.actualWorkers ?? this.config.workers;
+    const jobs = this.config.actualWorkers ?? this.config.workers;
     const shardDetails = this.config.shard ? `, shard ${this.config.shard.current} of ${this.config.shard.total}` : '';
     if (!this.totalTestCount)
       return '';

packages/playwright/src/reporters/blob.ts

@@ -34,7 +34,7 @@ type BlobReporterOptions = {
   _commandHash: string;
 };
 
-export const currentBlobReportVersion = 2;
+export const currentBlobReportVersion = 3;
 
 export type BlobReportMetadata = {
   version: number;
@@ -49,7 +49,6 @@ export class BlobReporter extends TeleReporterEmitter {
   private readonly _attachments: { originalPath: string, zipEntryPath: string }[] = [];
   private readonly _options: BlobReporterOptions;
   private readonly _salt: string;
-  private _config!: FullConfig;
 
   constructor(options: BlobReporterOptions) {
     super(message => this._messages.push(message));
@@ -72,7 +71,6 @@ export class BlobReporter extends TeleReporterEmitter {
       params: metadata
     });
 
-    this._config = config;
     super.onConfigure(config);
   }
 

packages/playwright/src/reporters/merge.ts

@@ -18,7 +18,7 @@ import fs from 'fs';
 import path from 'path';
 import type { ReporterDescription } from '../../types/test';
 import type { FullConfigInternal } from '../common/config';
-import type { JsonConfig, JsonEvent, JsonFullResult, JsonLocation, JsonProject, JsonSuite, JsonTestCase, JsonTestResultEnd, JsonTestStepStart } from '../isomorphic/teleReceiver';
+import type { JsonBeginParams, JsonConfig, JsonEvent, JsonFullResult, JsonLocation, JsonProject, JsonSuite, JsonTestCase, JsonTestResultEnd, JsonTestStepStart } from '../isomorphic/teleReceiver';
 import { TeleReporterReceiver } from '../isomorphic/teleReceiver';
 import { JsonStringInternalizer, StringInternPool } from '../isomorphic/stringInternPool';
 import { createReporters } from '../runner/reporters';
@@ -172,6 +172,7 @@ async function mergeEvents(dir: string, shardReportFiles: string[], stringPool:
 
   const configureEvents: JsonEvent[] = [];
   const projectEvents: JsonEvent[] = [];
+  const beginEvents: JsonEvent[] = [];
   const endEvents: JsonEvent[] = [];
 
   const blobs = await extractAndParseReports(dir, shardReportFiles, internalizer, printStatus);
@@ -214,6 +215,8 @@ async function mergeEvents(dir: string, shardReportFiles: string[], stringPool:
     for (const event of parsedEvents) {
       if (event.method === 'onConfigure')
         configureEvents.push(event);
+      else if (event.method === 'onBegin')
+        beginEvents.push(event);
       else if (event.method === 'onProject')
         projectEvents.push(event);
       else if (event.method === 'onEnd')
@@ -232,7 +235,7 @@ async function mergeEvents(dir: string, shardReportFiles: string[], stringPool:
     prologue: [
       mergeConfigureEvents(configureEvents, rootDirOverride),
       ...projectEvents,
-      { method: 'onBegin', params: undefined },
+      mergeBeginEvents(beginEvents),
     ],
     reports,
     epilogue: [
@@ -288,6 +291,20 @@ function mergeConfigureEvents(configureEvents: JsonEvent[], rootDirOverride: str
   };
 }
 
+function mergeBeginEvents(beginEvents: JsonEvent[]): JsonEvent {
+  let actualWorkers = 0;
+  for (const event of beginEvents) {
+    const params = event.params as JsonBeginParams;
+    actualWorkers += params.actualWorkers;
+  }
+  return {
+    method: 'onBegin',
+    params: {
+      actualWorkers,
+    }
+  };
+}
+
 function mergeConfigs(to: JsonConfig, from: JsonConfig): JsonConfig {
   return {
     ...to,
@@ -295,7 +312,6 @@ function mergeConfigs(to: JsonConfig, from: JsonConfig): JsonConfig {
     metadata: {
       ...to.metadata,
       ...from.metadata,
-      actualWorkers: (to.metadata.actualWorkers || 0) + (from.metadata.actualWorkers || 0),
     },
     workers: to.workers + from.workers,
   };
@@ -548,6 +564,8 @@ class JsonEventPatchers {
 }
 
 class BlobModernizer {
+  private _2to3actualWorkers?: number;
+
   modernize(fromVersion: number, events: JsonEvent[]): JsonEvent[] {
     const result = [];
     for (const event of events)
@@ -577,6 +595,23 @@ class BlobModernizer {
       return event;
     });
   }
+
+  _modernize_2_to_3(events: JsonEvent[]): JsonEvent[] {
+    // Migrate from onConfigure.config.metadata.actualWorkers to onBegin.actualWorkers.
+    return events.map(event => {
+      if (event.method === 'onConfigure') {
+        const config = event.params.config as JsonConfig;
+        this._2to3actualWorkers = config.metadata.actualWorkers;
+        delete config.metadata.actualWorkers;
+      }
+      if (event.method === 'onBegin') {
+        event.params = event.params || {};
+        if (event.params.actualWorkers === undefined && this._2to3actualWorkers !== undefined)
+          (event.params as JsonBeginParams).actualWorkers = this._2to3actualWorkers;
+      }
+      return event;
+    });
+  }
 }
 
 const modernizer = new BlobModernizer();

packages/playwright/src/reporters/teleEmitter.ts

@@ -30,7 +30,7 @@ export type TeleReporterEmitterOptions = {
 
 export class TeleReporterEmitter implements ReporterV2 {
   private _messageSink: (message: teleReceiver.JsonEvent) => void;
-  private _rootDir!: string;
+  protected _config!: reporterTypes.FullConfig;
   private _emitterOptions: TeleReporterEmitterOptions;
   // In case there is blob reporter and UI mode, make sure one does override
   // the id assigned by the other.
@@ -46,7 +46,7 @@ export class TeleReporterEmitter implements ReporterV2 {
   }
 
   onConfigure(config: reporterTypes.FullConfig) {
-    this._rootDir = config.rootDir;
+    this._config = config;
     this._messageSink({ method: 'onConfigure', params: { config: this._serializeConfig(config) } });
   }
 
@@ -54,7 +54,8 @@ export class TeleReporterEmitter implements ReporterV2 {
     const projects = suite.suites.map(projectSuite => this._serializeProject(projectSuite));
     for (const project of projects)
       this._messageSink({ method: 'onProject', params: { project } });
-    this._messageSink({ method: 'onBegin', params: undefined });
+    const beginParams: teleReceiver.JsonBeginParams = { actualWorkers: this._config.actualWorkers };
+    this._messageSink({ method: 'onBegin', params: beginParams });
   }
 
   onTestBegin(test: reporterTypes.TestCase, result: reporterTypes.TestResult): void {
@@ -280,6 +281,6 @@ export class TeleReporterEmitter implements ReporterV2 {
   private _relativePath(absolutePath?: string): string | undefined {
     if (!absolutePath)
       return absolutePath;
-    return path.relative(this._rootDir, absolutePath);
+    return path.relative(this._config.rootDir, absolutePath);
   }
 }

packages/playwright/src/runner/tasks.ts

@@ -291,7 +291,7 @@ function createPhasesTask(): Task<TestRun> {
         }
       }
 
-      testRun.config.config.metadata.actualWorkers = Math.min(testRun.config.config.workers, maxConcurrentTestGroups);
+      testRun.config.setActualWorkers(Math.min(testRun.config.config.workers, maxConcurrentTestGroups));
     },
   };
 }

packages/playwright/types/test.d.ts

@@ -1707,6 +1707,15 @@ export interface FullConfig<TestArgs = {}, WorkerArgs = {}> {
    * See [testConfig.webServer](https://playwright.dev/docs/api/class-testconfig#test-config-web-server).
    */
   webServer: TestConfigWebServer | null;
+  /**
+   * The actual number of worker processes used for running tests. This number depends on the maximum number of workers
+   * specified in [testConfig.workers](https://playwright.dev/docs/api/class-testconfig#test-config-workers), the list
+   * of running tests and their mode of parallel or sequential execution.
+   *
+   * This property is only available after tests have started running.
+   */
+  actualWorkers: number;
+
   /**
    * Path to the configuration file used to run the tests. The value is an empty string if no config file was used.
    */

tests/playwright-test/config.spec.ts

@@ -661,3 +661,28 @@ test('should merge ct configs', async ({ runInlineTest }) => {
   });
   expect(result.exitCode).toBe(0);
 });
+
+test('should expose actualWorkers', async ({ runInlineTest }) => {
+  const result = await runInlineTest({
+    'playwright.config.ts': `
+      module.exports = { workers: 42 };
+    `,
+    'a.test.ts': `
+      import { test, expect } from '@playwright/test';
+
+      test('pass', async ({}) => {
+        expect(test.info().config.actualWorkers).toBe(2);
+      });
+    `,
+    'b.test.ts': `
+      import { test, expect } from '@playwright/test';
+
+      test('pass', async ({}) => {
+        expect(test.info().config.actualWorkers).toBe(2);
+      });
+    `,
+  });
+  expect(result.exitCode).toBe(0);
+  expect(result.passed).toBe(2);
+  expect(result.output).toContain('Running 2 tests using 2 workers');
+});

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

@@ -1421,7 +1421,7 @@ test('blob report should include version', async ({ runInlineTest }) => {
 
   const events = await extractReport(test.info().outputPath('blob-report', 'report.zip'), test.info().outputPath('tmp'));
   const metadataEvent = events.find(e => e.method === 'onBlobReportMetadata');
-  expect(metadataEvent.params.version).toBe(2);
+  expect(metadataEvent.params.version).toBe(3);
   expect(metadataEvent.params.userAgent).toBe(getUserAgent());
 });