pragma Strict does not work

pragma Strict
import QtQuick
import QtQuick.Controls
import QtQuick.Dialogs
ApplicationWindow {
    width: 640
    height: 480
    visible: true
    title: qsTr("Native Dialogs Issue")   
 FileDialog {        
        Component.onCompleted: open()
        visible: true
    }
    TextArea {
        id: textArea
        textFormat: Qt.RichText
        wrapMode: TextArea.Wrap
        focus: true
        text: "Gekki"    }
}