unable to use TestCase.qml/module "Qt.test.qtestroot" is not installed

Hi,

I'm enable to run a  simple qml  file with a qml TestCase :

python

from PySide2.QtGui import QGuiApplication
 from PySide2.QtQml import QQmlApplicationEngine
 from os.path import *
 import sys
if _name_ == '_main_':
 app = QGuiApplication(sys.argv)
 engine = QQmlApplicationEngine()
engine.load(join(dirname(_file_), 'main.qml'))
if not engine.rootObjects():
 sys.exit(-1)
sys.exit(app.exec_())

main.qml :

import QtQuick 2.12
 import QtTest 1.2
Item {
TestCase {
 name: "MathTests"
function test_math()
{ compare(2 + 2, 4, "2 + 2 = 4") }
}}

I have the following error message :

file:///XXX/untitled/main.qml:6
file:///XXX/untitled/main.qml:6 Type TestCase unavailable
file://XXXX/untitled/.venv/lib/python3.7/site-packages/PySide2/Qt/qml/QtTest/TestCase.qml:44 module "Qt.test.qtestroot" is not installed

 The file is valid : running from qmltestrunner :

• • • • • • • • • Start testing of qmltestrunner *********
                  Config: Using QtTest library 5.12.6, Qt 5.12.6 (x86_64-little_endian-lp64 shared (dynamic) release build; by GCC 5.3.1 20160406 (Red Hat 5.3.1-6))
                  PASS : qmltestrunner::MathTests::initTestCase()
                  PASS : qmltestrunner::MathTests::test_math()
                  PASS : qmltestrunner::MathTests::cleanupTestCase()
                  Totals: 3 passed, 0 failed, 0 skipped, 0 blacklisted, 3ms
                • Finished testing of qmltestrunner *********

```