[Feature] Recording actual values in HAR file / recordHar

recordHar is a great option for analyzing and debugging HTTP requests and responses, especially since there doesn’t seem to be browser support for generating HAR files via the command-line.

There seem to be several placeholder values in the resulting HAR file as generated by harTracer.ts. For example, HTTP version is always set to HTTP/1.1, and other fields are always set to -1:

https://github.com/microsoft/playwright/blob/da1dafcadb05fd648f13610d8eefc4baa5c2261e/src/server/supplements/har/harTracer.ts#L151-L164

It seems like many (if not all?) of the placeholder values could be replaced with the actual values from network.Request and network.Response: is there any reason why that wouldn’t work? Are there any particular cross-platform or cross-browser issues to consider?

I’m implementing this feature for my own use and more than happy to push it upstream for review and feedback.

[mxschmitt]

Closing since HAR has now more sizes, httpVersion, etc. Please create a new issue which fields are exactly missing, thanks!

[tnolet]

@cardi @dgozman just hopping in here to show interest. Mostly the size properties are very relevant to many use cases with the HAR file, e.g.

   content: { 
     size: -1, 
     mimeType: 'foo'
   }, 
   headersSize: -1, 
   bodySize: -1, 

Having these values as -1 prohibits analyses on, well, file and transfer sizes. Will have a stab at providing a PR.