Parser-blocking warning appearing on <link rel="preload"/>
Reported by
eduard....@marfeel.com,
Jul 21 2017
|
|||||||
Issue descriptionUserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36 Steps to reproduce the problem: 1. go to website: https://mediamai.marfeel.com/www.davidemaggio.it/index.html?marfeeltn=k&marfeeldt=s 2. Inspect, you will se the warning. gardac.js:15 A Parser-blocking, cross site (i.e. different eTLD+1) script, https://mediamai.marfeel.com/statics/marfeel/k.s.js?buildNumber=161114140941, is invoked via document.write. The network request for this script MAY be blocked by the browser in this or a future page load due to poor network connectivity. If blocked in this page load, it will be confirmed in a subsequent console message.See https://www.chromestatus.com/feature/5718547946799104 for more details. 3. The problem it's that there is a link with preload and this is causing the warning. <link rel="preload" href="https://mediamai.marfeel.com/statics/marfeel/k.s.js" as="script"> This warning was done to parser-blacking scripts, but a preload it's not parser-blocking. What is the expected behavior? Not have the warning, as a <link rel="preload"> it's not parser-blocking. What went wrong? A warning apperaed but doesn't apply to <link rel="preload"/> Did this work before? N/A Does this work in other browsers? Yes Chrome version: 59.0.3071.115 Channel: stable OS Version: OS X 10.12.5 Flash Version:
,
Jul 26 2017
,
Aug 2 2017
Tested this issue on Mac 10.12.6 with chrome #59.0.3071.115 Steps Followed: 1. In the New tab, open devtools --> Emulating device 2. Navigate to the test link provided in comment #0 3. Open the console Didn't observe any error message as mentioned in step-2 & Step-3 in comment #0 Attaching the screenshot for reference. eduard.cot@ could you please look into it and let us know any steps i have missed while reproducing the scenario.
,
Aug 2 2017
The warning seems to happen only for cross-origin requests. kkulari could you try with the url https://www.davidemaggio.it/ I can see the warning message there
,
Aug 10 2017
,
Aug 10 2017
I can repro with the link in #4. It looks like this is coming from document.write[1], though it is also preloaded elsewhere. This is still bad for performance though it is better than not also preloading the script. +shivanisha,bmcquade [1] The initiator being gardac.js:15 indicates this was via document.write.
,
Aug 10 2017
,
Aug 11 2017
This isn't repro-ing for me on either the originally shared URL or the URL in #4. IIUC the script is later being loaded via document.write, after having been preloaded. If that's the case, this is working as intended. There's no guarantee that the preload will always be finished by the time the doc.write executes, which still makes this costly. We want to discourage using doc.write to load parser-blocking scripts, rather than encourage people to try to work around with preload etc.
,
Aug 25 2017
(Blink>Loader triager here) Sounds like this is working as intended. |
|||||||
►
Sign in to add a comment |
|||||||
Comment 1 by eduard....@marfeel.com
, Jul 25 2017