Sitespeed.io is calculating CSS and Javascript size incorrectly

[abhagupta]

Hi,

I have a HAR file which is capturing the CSS and JAVASCRIPTs incorrectly. I see the content size of these content types as 0 in the reports even though I see HAR file has CSS and Javascript files.

I am trying to trace down the code which calculates the CSS and Javascript size in PageXray but may be you can tell me more how this is calculated.

HAR file : https://github.com/abhagupta/sample_browsertime/blob/master/browsertime.json

[soulgalore]

Hi @abhagupta thanks for reporting, hmm, looked at the HAR and the response is 304, so I think it could be that we in PageXray only look for 2XX responses when calculating the total size? Let men check that later on today.

Best
Peter

[soulgalore]

@abhagupta I've pushed the change in master, hopefully making a release first thing tomorrow.

[abhagupta]

Thanks so much for taking care of this so quickly. I will try it out today.

[abhagupta]

@soulgalore On curious note, I am wondering how can we get a 304 anyways. 304 means browser recieved it from cache. But this should not have happened in sitespeed.io / selenium anyway.. am i missing something?

[soulgalore]

@abhagupta hmm how are you running (I was thinking you where using a preScript or preURL)? Was it Chrome or FF? By default we use Selenium by creating a new profile etc but you can as extra functionality also add --cacheClearRaw (or --browsertime.cacheClearRaw), then instead of trusting Selenium, we use the Browsertime extension (the WebExtension) to fully clear the cache https://github.com/sitespeedio/browsertime-extension/blob/master/background.js#L146-L164 - I personally always use that last option when running in Docker, it probably be a thing we should add by default.

[abhagupta]

Yes we are using a preScript. It does make sense now that it would get 304. I will use the --cacheClearRaw and try it. Thanks

[soulgalore]

Ah sorry, I didn't explain it clear enough. The --cacheClearRaw happens before a run (before preScript/preURL). I've seen people in issues trying to disable the cache for Chrome to achieve not caching in pre steps but I haven't fully been able to understand the use case?

[soulgalore]

Checkout sitespeedio/chrome-har#1

[abhagupta]

Ah cool.. so its not just me. And it makes much more sense now. I tried to reproduce this on Chrome Dev tools and I saw a similar behavior what sitespeed was showing.. My preScript creates a cookie on the page and refreshes it. So I am definitely on the same page with same assets when its reloaded after cookie is inserted. When I open my app in chrome and check chrome dev tools, I see I get 304 responses for these CSS and Javascript files. (I made sure that I have Disable Cache unhecked, meaning I am letting Chrome to cache the assets). Selenium is doing exact behavior. If I do not clear the cache explicitly in my preScript after loading the cookie, browser is going to load it from cache. Thats what it is meant to do.

Btw. I used the --browsertime.cacheClearRaw and it worked. I do get a 200 response in the HAR file and also the metrics that I am expecting. So you might be ok NOT pushing the change you made.

Are you sure about The --cacheClearRaw happens before a run (before preScript/preURL) though?

I think otherwise because --browsertime.cacheClearRaw browsertime is going to clear the cache before it starts testing for performance which I am assuming starts after preScript is already executed. Correct me if I am wrong.

Thanks for all the help and information .

[abhagupta]

oops... i guess this option --browsertime.cacheClearRaw will remove my cookie
as well.

[abhagupta]

Yep, confirmed that cookie that I added in the preScript gets deleted becasue of --browsertime.cacheClearRaw. So may be we do need the pagexray change you made to capture content from 304 response. I will wait for the release. thanks again and sorry for spamming this issue .

[abhagupta]

@soulgalore please let me know if the release to pagexray has been made.

[soulgalore]

@abhagupta it is released but not sitespeed.io yet.

[soulgalore]

@abhagupta released it just now, the container should be there in 5 min.

[soulgalore]

Released some time ago, hope it works fine :)