Add QUICK_TEST_MAIN_WITH_SETUP to allow executing C++ before a QML test

This macro is the same as QUICK_TEST_MAIN, but takes the user's
QObject subclass as an argument, and calls pre-defined slots/invokable
functions on it, similar to how e.g. init() is called for C++ tests.

This allows e.g. context properties to be set for the QML tests.

By basing the API on invokable functions, we give ourselves the freedom
to easily add more functions in the future.

[ChangeLog][QtQuickTest] Added QUICK_TEST_MAIN_WITH_SETUP macro to
allow executing C++ before a QML test (such as registering context
properties).

Task-number: QTBUG-50064
Change-Id: Id566e388553811c220871248403d32545f8ae1eb
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/qmltest/quicktest.cpp b/src/qmltest/quicktest.cpp
index 463833a100..817f9a5389 100644
--- a/src/qmltest/quicktest.cpp
+++ b/src/qmltest/quicktest.cpp
@@ -327,6 +327,11 @@ private:
 
 int quick_test_main(int argc, char **argv, const char *name, const char *sourceDir)
 {
+    return quick_test_main_with_setup(argc, argv, name, sourceDir, nullptr);
+}
+
+int quick_test_main_with_setup(int argc, char **argv, const char *name, const char *sourceDir, QObject *setup)
+{
     // Peek at arguments to check for '-widgets' argument
 #ifdef QT_QMLTEST_WITH_WIDGETS
     bool withWidgets = false;
@@ -516,6 +521,14 @@ int quick_test_main(int argc, char **argv, const char *name, const char *sourceD
         view.rootContext()->setContextProperty
             (QLatin1String("qtest"), QTestRootObject::instance()); // Deprecated. Use QTestRootObject from Qt.test.qtestroot instead
 
+        // Do this down here so that import paths, plugin paths,
+        // file selectors, etc. are available in case the user needs access to them.
+        if (setup) {
+            // Don't check the return value; it's OK if it doesn't exist.
+            // If we add more callbacks in the future, it makes sense if the user only implements one of them.
+            QMetaObject::invokeMethod(setup, "qmlEngineAvailable", Q_ARG(QQmlEngine*, view.engine()));
+        }
+
         view.setObjectName(fi.baseName());
         view.setTitle(view.objectName());
         QTestRootObject::instance()->init();