fix(trace): StdinServer._loadTrace does not convert file path to URI format

[li-zhixin]

Bug Description

In Playwright 1.58.0, the StdinServer._loadTrace() method in traceViewer.ts does not call validateTraceUrl() to convert file paths to the file?path= URI format. This causes the trace viewer to fail when receiving trace paths via stdin (used by VS Code extension for live trace).

Steps to Reproduce

1. Install Playwright 1.58.0 or 1.58.1
2. Use VS Code extension (v1.1.17) with "Show trace viewer" enabled
3. Run a test
4. Observe the trace viewer fails to load with error:

Not allowed to load local resource: file:///C:/Users/.../test-results/.playwright-artifacts-0/traces/xxx.json

Root Cause

In commit 185bfb7d4 ("fix(trace): operate trace uri, not path #38566"), the validateTraceUrl() function was updated to convert file paths to file?path= URI format. However, StdinServer._loadTrace() was not updated to use this function.

Current code (buggy):

private _loadTrace(traceUrl: string) {
  this._traceUrl = traceUrl;  // Raw file path sent to frontend
  clearTimeout(this._pollTimer);
  this.sendEvent?.('loadTraceRequested', { traceUrl });
}

Expected behavior:
The path should be converted using validateTraceUrl() before sending to frontend.

Affected Components

• VS Code extension live trace functionality
• Any client using --stdin mode with show-trace

Workaround

Apply this patch to node_modules/playwright-core/lib/server/trace/viewer/traceViewer.js:

   _loadTrace(traceUrl) {
-    this._traceUrl = traceUrl;
+    const validatedUrl = validateTraceUrl(traceUrl);
+    this._traceUrl = validatedUrl;
     clearTimeout(this._pollTimer);
-    this.sendEvent?.("loadTraceRequested", { traceUrl });
+    this.sendEvent?.("loadTraceRequested", { traceUrl: validatedUrl });
   }

For pnpm users, save this as patches/playwright-core@1.58.1.patch and add to package.json:

"pnpm": {
  "patchedDependencies": {
    "playwright-core@1.58.1": "patches/playwright-core@1.58.1.patch"
  }
}

Environment

• Playwright version: 1.58.0, 1.58.1
• VS Code extension version: 1.1.17
• OS: Windows 11
• Node.js: 20.x

Related

• Introduced in: fix(trace): operate trace uri, not path #38566

[arjunUnniumbath]

facing issue due to this in my local executions as well.. I end up getting all network calls with data as " < empty > "while going through traces ... and once in a. while error like unable to access local resources :)
eg of the trace error :
{
"error": "Could not load trace from file?path=%2FUsers%2Faju%2FWORK%2Freg-fe%2Ftest-results%2F.playwright-artifacts-0%2Ftraces%2F10a1fd2d9b7f3a3886a8-86a802880e58fb330d94.json&timestamp=1770212281796. Make sure a valid Playwright Trace is accessible over this url.\n\nIf your trace is in a local or private network, please grant permission for Local Network Access."
}