chromium/third_party/blink/web_tests/fast/forms/calendar-picker/date-picker-month-switcher-menu.html

<!DOCTYPE html>
<meta name=fuzzy content="maxDifference=0-3; totalPixels=0-1000">
<script src="../../../resources/testharness.js"></script>
<script src="../../../resources/testharnessreport.js"></script>
<script src="../../../resources/testdriver.js"></script>
<script src="../../../resources/testdriver-vendor.js"></script>
<script src="../resources/common.js"></script>
<script src="../resources/picker-common.js"></script>
<script src="../calendar-picker/resources/calendar-picker-common.js"></script>

<input type="date" id="date-0" value="2019-02-14">
<input type="date" id="date-1" value="2019-02-14">
<input type="date" id="date-2">
<script>

promise_test(() => {
  let dateElement = document.getElementById('date-0');
  return openPicker(dateElement)
  .then(() => {
    // Make the picker dismiss synchronously so we don't need to insert
    // an artificial delay in the test
    internals.pagePopupWindow.CalendarPicker.commitDelayMs = 0;

    clickMonthPopupButton();
    eventSender.keyDown('ArrowRight');
    eventSender.keyDown('ArrowDown');
    eventSender.keyDown('Enter');
    assert_equals(dateElement.value, "2019-07-14", "Month chooser button should have changed month");

    clickDayCellAt(2, 3);
    assert_equals(dateElement.value, "2019-07-23", "Clicking date should have changed date");
    assert_equals(internals.pagePopupWindow, null, "Clicking date should have dismissed popup.");
  });
}, "Date picker: Month chooser should allow user to chooser month");

promise_test(() => {
  let dateElement = document.getElementById('date-1');
  return openPicker(dateElement)
  .then(() => {
    // Make the picker dismiss synchronously so we don't need to insert
    // an artificial delay in the test
    internals.pagePopupWindow.CalendarPicker.commitDelayMs = 0;

    clickMonthPopupButton();
    eventSender.keyDown('ArrowRight');
    eventSender.keyDown('ArrowDown');
    eventSender.keyDown('Escape');
    clickDayCellAt(2, 3);

    assert_equals(dateElement.value, "2019-02-19", "Escape key should have dismissed month chooser without changing month ");
  });
}, "Date picker: Month chooser should dismiss on Escape key");

promise_test(() => {
  let dateElement = document.getElementById('date-2');
  return openPicker(dateElement)
  .then(() => {
    clickMonthPopupButton();
    eventSender.keyDown('Enter');

    let splitDate = dateElement.value.split('-');
    let actualTodayDateString = new Date(splitDate[0], splitDate[1] - 1, [splitDate[2]]).toDateString();
    let expectedTodayDateString = new Date().toDateString();

    assert_equals(actualTodayDateString, expectedTodayDateString, "Opening month switcher should push value to in-page control if it has no initial value.");
    eventSender.keyDown('Escape');
    assert_equals(internals.pagePopupWindow, null, "Enter key should dismiss popup.");
  });
}, "Date picker: Opening month chooser should push value to in-page control -- no initial value");

</script>