(In reply to Kartikaya Gupta (email:kats@mozilla.com) from comment #23) > Another thing that might be worth doing is trying to make tests use meta tags for controlling initial zoom level instead of reftest-resolution attributes. I'm not sure if that always works (e.g. might need to set prefs for desktop) but it would probably be more representative of real-world pages. Actually, we introduced `reftest-resolution` specifically so that we write tests that exercise the main-thread zooming codepaths without requiring mobile viewport sizing. I wrote an explanation of this in bug 1554790 which introduced the attribute: > However, processing a meta viewport tag has side effects beyond setting a resolution: it triggers the mobile viewport sizing logic added in bug 1423013 and relatives. > > For desktop zooming, we'd like to be able to test painting with a resolution without triggering the mobile viewport sizing logic. (For at least two reasons: (1) we want to be testing configurations that are as close as possible to what happens in production; and (2) the mobile viewport sizing logic has interactions with layout scrollbars and I'd rather not support the combination if I don't have to.)
Bug 1620679 Comment 24 Edit History
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(In reply to Kartikaya Gupta (email:kats@mozilla.com) from comment #23) > Another thing that might be worth doing is trying to make tests use meta tags for controlling initial zoom level instead of reftest-resolution attributes. I'm not sure if that always works (e.g. might need to set prefs for desktop) but it would probably be more representative of real-world pages. Actually, we introduced `reftest-resolution` specifically so that we can write tests that exercise the main-thread zooming codepaths without requiring mobile viewport sizing. I wrote an explanation of this in bug 1554790 which introduced the attribute: > However, processing a meta viewport tag has side effects beyond setting a resolution: it triggers the mobile viewport sizing logic added in bug 1423013 and relatives. > > For desktop zooming, we'd like to be able to test painting with a resolution without triggering the mobile viewport sizing logic. (For at least two reasons: (1) we want to be testing configurations that are as close as possible to what happens in production; and (2) the mobile viewport sizing logic has interactions with layout scrollbars and I'd rather not support the combination if I don't have to.)