mouseClick does not work

import QtQuick 2.15
import QtTest 1.0
import QtQuick.Controls

TestCase {
    name: "MyTestcase"

    Button {
        id: button
        onClicked: console.log("onClicked")
    }

    MouseArea {
        id: mouseArea
        width: 100
        height: 100
        onClicked: console.log("onClicked")
    }

    SignalSpy {
        id: spy
        target: mouseArea
        signalName: "onClicked"
    }

    function initTestCase() {
    }

    function cleanupTestCase() {
    }

    function test_case1() {
        mouseClick(button)
        mouseClick(mouseArea)
        spy.wait()
    }
}

TestCase {
    name: "MyTestcase"
    when: windowShown

    Window {
        id: window
        Component {
            id: button
            MouseArea {
                onClicked: console.log("onClicked")
            }
        }
    }

    function test_case1() {
        var item = createTemporaryObject(button, window);
        mouseClick(item);
    }
}