core(emulation): set client-hints metadata when spoofing the UA #13341
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| const version = fullVersion.split('.', 1)[0]; | ||
| const brands = [ | ||
| {brand: 'Chromium', version}, | ||
| {brand: 'Google Chrome', version}, |
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wdyt of adding a entry for LH version here?
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and if we do that, we should randomly sort the array, to support the GREASE stuffs (or will chrome do that for us in the request headers?)
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wdyt of adding a entry for LH version here?
done
and if we do that, we should randomly sort the array, to support the GREASE stuffs (or will chrome do that for us in the request headers?)
seems like fun.. and its jsut adding a .sort(_ => Math.random() - 0.5)
... but we add some non-determinimism without much gain so i think we should put it off. leave the greasing to the big boiz.
| await session.sendCommand('Network.setUserAgentOverride', { | ||
| userAgent: /** @type {string} */ (settings.emulatedUserAgent), | ||
| userAgent, | ||
| userAgentMetadata: parseUseragentIntoMetadata(userAgent, settings.formFactor), | ||
| }); | ||
| } | ||
| // See devtools-entry for one usecase for disabling screenEmulation |
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needs tests, esp. for the case where the UA is user-provided and doesn't even have a chrome version in it
lighthouse-core/lib/emulation.js
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| function parseUseragentIntoMetadata(userAgent, formFactor) { | ||
| const match = userAgent.match(/Chrome\/([\d.]+)/); // eg 'Chrome/(71.0.3577.0)' | ||
| const fullVersion = (match && match[1]) || '99.0.1234.0'; | ||
| const version = fullVersion.split('.', 1)[0]; |
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| const version = fullVersion.split('.', 1)[0]; | |
| const [version] = fullVersion.split('.', 1); |
😎
We've discovered that some webservers misbehave when they get a mobile useragent but empty clienthints headers.
And since a while ago... when we set
Emulation.setUserAgentOverride.. it appropriately sets the useragent string, but since nouserAgentMetadatawas provided, all those values are undefined. As client hints are being adopted, this leads to weird and brokenish scenarios. (depending on how defensive folks are configuring their ua handling on the webserver side).We'll want to make sure clienthint headers are appropriately populated.
I went for making a change that minimizes impact on people who configure lighthouse with custom UA. I think we can revisit exactly how to expose those fields. I'd go for something less verbose than pptr's choice of replicating the exact same payload.