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<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<script>
function waitForCondition(aCond, aCallback, aErrorMsg) {
var tries = 0;
var interval = setInterval(() => {
if (tries >= 30) {
opener.ok(false, aErrorMsg);
moveOn();
return;
}
var conditionPassed;
try {
conditionPassed = aCond();
} catch (e) {
opener.ok(false, `${e}\n${e.stack}`);
conditionPassed = false;
}
if (conditionPassed) {
moveOn();
}
tries++;
}, 100);
var moveOn = () => { clearInterval(interval); aCallback(); };
}
function runTest() {
let expectedPrecision = opener.expectedPrecision / 1000;
let isRounded = (x) => {
let rounded = (Math.floor(x / expectedPrecision) * expectedPrecision);
// First we do the perfectly normal check that should work just fine
if (rounded === x || x === 0)
return true;
// When we're diving by non-whole numbers, we may not get perfect
// multiplication/division because of floating points.
// When dealing with ms since epoch, a double's precision is on the order
// of 1/5 of a microsecond, so we use a value a little higher than that as
// our epsilon.
// To be clear, this error is introduced in our re-calculation of 'rounded'
// above in JavaScript.
if (Math.abs(rounded - x + expectedPrecision) < .0005) {
return true;
} else if (Math.abs(rounded - x) < .0005) {
return true;
}
// Then we handle the case where you're sub-millisecond and the timer is not
// We check that the timer is not sub-millisecond by assuming it is not if it
// returns an even number of milliseconds
if (expectedPrecision < 1 && Math.round(x) == x) {
if (Math.round(rounded) == x) {
return true;
}
}
// We are temporarily disabling this extra debugging failure because we expect to return false in some instances
// When we correct things we will re-enable it for debugging assistance
// opener.ok(false, "Looming Test Failure, Additional Debugging Info: Expected Precision: " + expectedPrecision + " Measured Value: " + x +
// " Rounded Vaue: " + rounded + " Fuzzy1: " + Math.abs(rounded - x + expectedPrecision) +
// " Fuzzy 2: " + Math.abs(rounded - x));
return false;
};
const testDiv = document.getElementById("testDiv");
const animation = testDiv.animate({ opacity: [0, 1] }, 100000);
animation.play();
waitForCondition(
() => animation.currentTime > 100,
() => {
// We have disabled Time Precision Reduction for CSS Animations, so we expect those tests to fail.
// If we are testing that preference, we accept either rounded or not rounded values as A-OK.
var maybeAcceptEverything = function(value) {
if (opener.prefName.includes("privacy.reduceTimerPrecision") &&
!opener.prefName.includes("privacy.resistFingerprinting"))
return true;
return value;
};
opener.ok(maybeAcceptEverything(isRounded(animation.startTime)),
"pref: " + opener.prefName + " - animation.startTime with precision " + expectedPrecision + " is not rounded: " + animation.startTime);
opener.ok(maybeAcceptEverything(isRounded(animation.currentTime)),
"pref: " + opener.prefName + " - animation.currentTime with precision " + expectedPrecision + " is not rounded: " + animation.currentTime);
opener.ok(maybeAcceptEverything(isRounded(animation.timeline.currentTime)),
"pref: " + opener.prefName + " - animation.timeline.currentTime with precision " + expectedPrecision + " is not rounded: " + animation.timeline.currentTime);
if (document.timeline) {
opener.ok(maybeAcceptEverything(isRounded(document.timeline.currentTime)),
"pref: " + opener.prefName + " - document.timeline.currentTime with precision " + expectedPrecision + " is not rounded: " + document.timeline.currentTime);
}
opener.done();
window.close();
},
"animation failed to start");
}
</script>
</head>
<body onload="runTest();">
<div id="testDiv">test</div>
</body>
</html>