chore: pass "live" flag explicitly instead of through env var (#38217)

Author: dgozman

packages/playwright-core/src/client/tracing.ts

@@ -22,6 +22,7 @@ import type * as channels from '@protocol/channels';
 
 export class Tracing extends ChannelOwner<channels.TracingChannel> implements api.Tracing {
   private _includeSources = false;
+  private _isLive = false;
   _tracesDir: string | undefined;
   private _stacksId: string | undefined;
   private _isTracing = false;
@@ -37,21 +38,22 @@ export class Tracing extends ChannelOwner<channels.TracingChannel> implements ap
   async start(options: { name?: string, title?: string, snapshots?: boolean, screenshots?: boolean, sources?: boolean, _live?: boolean } = {}) {
     await this._wrapApiCall(async () => {
       this._includeSources = !!options.sources;
+      this._isLive = !!options._live;
       await this._channel.tracingStart({
         name: options.name,
         snapshots: options.snapshots,
         screenshots: options.screenshots,
         live: options._live,
       });
       const { traceName } = await this._channel.tracingStartChunk({ name: options.name, title: options.title });
-      await this._startCollectingStacks(traceName);
+      await this._startCollectingStacks(traceName, this._isLive);
     });
   }
 
   async startChunk(options: { name?: string, title?: string } = {}) {
     await this._wrapApiCall(async () => {
       const { traceName } = await this._channel.tracingStartChunk(options);
-      await this._startCollectingStacks(traceName);
+      await this._startCollectingStacks(traceName, this._isLive);
     });
   }
 
@@ -63,12 +65,12 @@ export class Tracing extends ChannelOwner<channels.TracingChannel> implements ap
     await this._channel.tracingGroupEnd();
   }
 
-  private async _startCollectingStacks(traceName: string) {
+  private async _startCollectingStacks(traceName: string, live: boolean) {
     if (!this._isTracing) {
       this._isTracing = true;
       this._connection.setIsTracing(true);
     }
-    const result = await this._connection.localUtils()?.tracingStarted({ tracesDir: this._tracesDir, traceName });
+    const result = await this._connection.localUtils()?.tracingStarted({ tracesDir: this._tracesDir, traceName, live });
     this._stacksId = result?.stacksId;
   }
 

packages/playwright-core/src/protocol/validator.ts

@@ -317,6 +317,7 @@ scheme.LocalUtilsConnectResult = tObject({
 scheme.LocalUtilsTracingStartedParams = tObject({
   tracesDir: tOptional(tString),
   traceName: tString,
+  live: tOptional(tBoolean),
 });
 scheme.LocalUtilsTracingStartedResult = tObject({
   stacksId: tString,

packages/playwright-core/src/server/localUtils.ts

@@ -38,6 +38,7 @@ export type StackSession = {
   writer: Promise<void>;
   tmpDir: string | undefined;
   callStacks: channels.ClientSideCallMetadata[];
+  live?: boolean;
 };
 
 export async function zip(progress: Progress, stackSessions: Map<string, StackSession>, params: channels.LocalUtilsZipParams): Promise<void> {
@@ -194,7 +195,7 @@ export async function tracingStarted(progress: Progress, stackSessions: Map<stri
   if (!params.tracesDir)
     tmpDir = await progress.race(fs.promises.mkdtemp(path.join(os.tmpdir(), 'playwright-tracing-')));
   const traceStacksFile = path.join(params.tracesDir || tmpDir!, params.traceName + '.stacks');
-  stackSessions.set(traceStacksFile, { callStacks: [], file: traceStacksFile, writer: Promise.resolve(), tmpDir });
+  stackSessions.set(traceStacksFile, { callStacks: [], file: traceStacksFile, writer: Promise.resolve(), tmpDir, live: params.live });
   return { stacksId: traceStacksFile };
 }
 
@@ -205,7 +206,7 @@ export async function traceDiscarded(progress: Progress, stackSessions: Map<stri
 export function addStackToTracingNoReply(stackSessions: Map<string, StackSession>, params: channels.LocalUtilsAddStackToTracingNoReplyParams) {
   for (const session of stackSessions.values()) {
     session.callStacks.push(params.callData);
-    if (process.env.PW_LIVE_TRACE_STACKS) {
+    if (session.live) {
       session.writer = session.writer.then(() => {
         const buffer = Buffer.from(JSON.stringify(serializeClientSideCallMetadata(session.callStacks)));
         return fs.promises.writeFile(session.file, buffer);

packages/playwright/src/runner/testRunner.ts

@@ -324,10 +324,6 @@ export class TestRunner extends EventEmitter<TestRunnerEventMap> {
       ...(params.updateSourceMethod ? { updateSourceMethod: params.updateSourceMethod } : {}),
       ...(params.workers ? { workers: params.workers } : {}),
     };
-    if (params.trace === 'on')
-      process.env.PW_LIVE_TRACE_STACKS = '1';
-    else
-      process.env.PW_LIVE_TRACE_STACKS = undefined;
 
     const config = await this._loadConfigOrReportError(new InternalReporter([userReporter]), overrides);
     if (!config)

packages/protocol/src/channels.d.ts

@@ -533,9 +533,11 @@ export type LocalUtilsConnectResult = {
 export type LocalUtilsTracingStartedParams = {
   tracesDir?: string,
   traceName: string,
+  live?: boolean,
 };
 export type LocalUtilsTracingStartedOptions = {
   tracesDir?: string,
+  live?: boolean,
 };
 export type LocalUtilsTracingStartedResult = {
   stacksId: string,

packages/protocol/src/protocol.yml

@@ -709,6 +709,7 @@ LocalUtils:
       parameters:
         tracesDir: string?
         traceName: string
+        live: boolean?
       returns:
         stacksId: string
 

tests/mcp/tracing.spec.ts

@@ -64,6 +64,7 @@ test('check that trace is saved with browser_start_tracing', async ({ startClien
   expect(files).toEqual([
     'resources',
     expect.stringMatching(/trace-\d+\.network/),
+    expect.stringMatching(/trace-\d+\.stacks/),
     expect.stringMatching(/trace-\d+\.trace/),
   ]);
 });
@@ -102,6 +103,7 @@ test('check that trace is saved with browser_start_tracing (no output dir)', asy
   expect(files).toEqual([
     'resources',
     expect.stringMatching(/trace-\d+\.network/),
+    expect.stringMatching(/trace-\d+\.stacks/),
     expect.stringMatching(/trace-\d+\.trace/),
   ]);
 });