Added two unit tests for alias nesting

The first test covers a use-case currently only otherwise see in
QtQuickControls, and so having it here allows for catching regressions in that
area before hitting the next qt5 build.

Having an alias refer to another alias property within the same file only works
if the second alias is resolved/processed before the first one. This works by
chance when relying on the order of processing reverse to the declaration, but
that's a bug. It should work regardless of the order. That is what the second
test-case demonstrates and that is why it is marked as failure.

Change-Id: Iba386437d21efa868d9814221092df5f7ef6f1f6
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

3 files changed, 61 insertions, 0 deletions

diff --git a/tests/auto/qml/qqmllanguage/data/alias.12.qml b/tests/auto/qml/qqmllanguage/data/alias.12.qml
new file mode 100644
index 0000000000..cc17318092
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/alias.12.qml
@@ -0,0 +1,15 @@
+import QtQml 2.0
+
+QtObject {
+    id: root
+    property alias topLevelAlias: subObject.targetProperty
+
+    property QtObject referencingSubObject: QtObject {
+        property alias success: root.topLevelAlias
+    }
+
+    property QtObject foo: QtObject {
+        id: subObject
+        property bool targetProperty: true
+    }
+}
diff --git a/tests/auto/qml/qqmllanguage/data/alias.13.qml b/tests/auto/qml/qqmllanguage/data/alias.13.qml
new file mode 100644
index 0000000000..cff8a72d9a
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/alias.13.qml
@@ -0,0 +1,16 @@
+import QtQml 2.0
+
+QtObject {
+    id: root
+    property bool targetProperty: true
+
+    property QtObject foo: QtObject {
+        id: otherSubObject
+        property alias theAlias: root.targetProperty
+    }
+
+    property QtObject referencingSubObject: QtObject {
+        property alias success: otherSubObject.theAlias
+    }
+
+}
diff --git a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
index 70db9aecd4..1e8e92217c 100644
--- a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
+++ b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
@@ -1803,6 +1803,36 @@ void tst_qqmllanguage::aliasProperties()
 
         delete object;
     }
+
+    // Nested aliases with a qml file
+    {
+        QQmlComponent component(&engine, testFileUrl("alias.12.qml"));
+        VERIFY_ERRORS(0);
+        QScopedPointer<QObject> object(component.create());
+        QVERIFY(!object.isNull());
+
+        QPointer<QObject> subObject = qvariant_cast<QObject*>(object->property("referencingSubObject"));
+        QVERIFY(!subObject.isNull());
+
+        QVERIFY(subObject->property("success").toBool());
+    }
+
+    // Nested aliases with a qml file with reverse ordering
+    {
+        // This is known to fail at the moment.
+        QQmlComponent component(&engine, testFileUrl("alias.13.qml"));
+        QVERIFY(!component.errors().isEmpty());
+#if 0
+        VERIFY_ERRORS(0);
+        QScopedPointer<QObject> object(component.create());
+        QVERIFY(!object.isNull());
+
+        QPointer<QObject> subObject = qvariant_cast<QObject*>(object->property("referencingSubObject"));
+        QVERIFY(!subObject.isNull());
+
+        QVERIFY(subObject->property("success").toBool());
+#endif
+    }
 }
 
 // QTBUG-13374 Test that alias properties and signals can coexist