Summary

• Fixes [🐛 Bug]: browser.uploadFile() can crash with RangeError: Too many properties to enumerate on large request bodies #15213
• In _request(), fullRequestOptions.body is already a JSON string at that point (stringified earlier in createOptions() via JSON.stringify(this.body)). Calling Object.keys() on a large string enumerates every character index as a property, causing V8 to throw RangeError: Too many properties to enumerate for large payloads (e.g., large screenshots or file uploads).
• Added a typeof fullRequestOptions.body === 'object' guard before the Object.keys() call so it only runs on actual objects, not strings.

Root cause

// createOptions() does:
requestOptions.body = JSON.stringify(this.body)

// Later in _request():
if (fullRequestOptions.body && Object.keys(fullRequestOptions.body).length) {
    this.eventHandler.onLogData?.(fullRequestOptions.body)
}

Object.keys('...large string...') returns an array of character indices (['0', '1', '2', ...]). For strings with millions of characters, V8 cannot enumerate that many properties and throws RangeError: Too many properties to enumerate.

Fix

if (fullRequestOptions.body && typeof fullRequestOptions.body === 'object' && Object.keys(fullRequestOptions.body).length) {

This ensures Object.keys() is only called when body is an actual object (which shouldn't happen in practice given the current flow, but guards against the string case safely).