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Test Info: Warnings
- This test has a WPT meta file that expects 5 subtest issues.
- This WPT test may be referenced by the following Test IDs:
- /performance-timeline/droppedentriescount.any.html - WPT Dashboard Interop Dashboard
- /performance-timeline/droppedentriescount.any.worker.html - WPT Dashboard Interop Dashboard
promise_test(t => {
// This setup is required for later tests as well.
// Await for a dropped entry.
return new Promise(res => {
// Set a buffer size of 0 so that new resource entries count as dropped.
performance.setResourceTimingBufferSize(0);
// Use an observer to make sure the promise is resolved only when the
// new entry has been created.
new PerformanceObserver(res).observe({type: 'resource'});
fetch('resources/square.png?id=1');
}).then(() => {
return new Promise(resolve => {
new PerformanceObserver(t.step_func((entries, obs, options) => {
assert_equals(options['droppedEntriesCount'], 0);
resolve();
})).observe({type: 'mark'});
performance.mark('test');
})});
}, 'Dropped entries count is 0 when there are no dropped entries of relevant type.');
promise_test(async t => {
return new Promise(resolve => {
new PerformanceObserver(t.step_func((entries, obs, options) => {
assert_equals(options['droppedEntriesCount'], 1);
resolve();
})).observe({entryTypes: ['mark', 'resource']});
performance.mark('meow');
});
}, 'Dropped entries correctly counted with multiple types.');
promise_test(t => {
return new Promise(resolve => {
new PerformanceObserver(t.step_func((entries, obs, options) => {
assert_equals(options['droppedEntriesCount'], 1,
'There should have been some dropped resource timing entries at this point');
resolve();
})).observe({type: 'resource', buffered: true});
});
}, 'Dropped entries counted even if observer was not registered at the time.');
promise_test(t => {
return new Promise(resolve => {
let callback_ran = false;
new PerformanceObserver(t.step_func((entries, obs, options) => {
if (!callback_ran) {
assert_equals(options['droppedEntriesCount'], 2,
'There should be two dropped entries right now.');
fetch('resources/square.png?id=3');
callback_ran = true;
} else {
assert_equals(options['droppedEntriesCount'], undefined,
'droppedEntriesCount should be unset after the first callback!');
resolve();
}
})).observe({type: 'resource'});
fetch('resources/square.png?id=2');
});
}, 'Dropped entries only surfaced on the first callback.');
promise_test(t => {
return new Promise(resolve => {
let callback_ran = false;
let droppedEntriesCount = -1;
new PerformanceObserver(t.step_func((entries, obs, options) => {
if (!callback_ran) {
assert_greater_than(options['droppedEntriesCount'], 0,
'There should be several dropped entries right now.');
droppedEntriesCount = options['droppedEntriesCount'];
callback_ran = true;
obs.observe({type: 'mark'});
performance.mark('woof');
} else {
assert_equals(options['droppedEntriesCount'], droppedEntriesCount,
'There should be droppedEntriesCount due to the new observe().');
resolve();
}
})).observe({type: 'resource'});
fetch('resources/square.png?id=4');
});
}, 'Dropped entries surfaced after an observe() call!');