window_size_rounding.html

Enable keyboard shortcuts

This WPT test may be referenced by the following Test IDs:
- /css/cssom/window_size_rounding.html - WPT Dashboard Interop Dashboard

<!doctype html>

<meta name="viewport" content="width=device-width, initial-scale=1.0">

<script src=/resources/testharness.js></script>

<script src=/resources/testharnessreport.js></script>

<iframe style="border: 0; padding: 0; width: 100.75px; height: 100.75px" srcdoc="<html style='width: 100vw; height: 100vh'>"></iframe>

<script>

onload = function() {

  test(() => {

    assert_equals(window.devicePixelRatio, 1, `precondition: ${window.innerWidth}x${window.innerHeight}`);

    // So that the 100.75 is fractional css pixel, but whole dev pixels, and representable in app units.

    SpecialPowers.setFullZoom(window, 4);

    let win = document.querySelector("iframe").contentWindow;

    const rounded = 101;

    const truncated = 100;

    const raw = 100.75;

    const rect = win.document.documentElement.getBoundingClientRect();

    assert_equals(rect.height, raw);

    assert_equals(rect.width, raw);

    switch (SpecialPowers.getIntPref("dom.innerSize.rounding")) {

      case 1:

        assert_equals(win.innerWidth, rounded);

        assert_equals(win.innerHeight, rounded);

        break;

      case 2:

        assert_equals(win.innerWidth, truncated);

        assert_equals(win.innerHeight, truncated);

        break;

      default:

        assert_equals(win.innerWidth, raw);

        assert_equals(win.innerHeight, raw);

        break;

    SpecialPowers.setFullZoom(window, 1);

})

};

</script>