STAR-322: Using a test setup to run tests with Cura app

plugins/UM3NetworkPrinting/tests/conftest.py

@@ -0,0 +1,37 @@
+# Copyright (c) 2018 Ultimaker B.V.
+# Uranium is released under the terms of the LGPLv3 or higher.
+
+import pytest
+import Arcus #Prevents error: "PyCapsule_GetPointer called with incorrect name" with conflicting SIP configurations between Arcus and PyQt: Import Arcus first!
+from UM.Qt.QtApplication import QtApplication # QT application import is required, even though it isn't used.
+from UM.Application import Application
+from UM.Signal import Signal
+
+from cura.CuraApplication import CuraApplication
+
+
+# This mock application must extend from Application and not QtApplication otherwise some QObjects are created and
+# a segfault is raised.
+class FixtureApplication(CuraApplication):
+    def __init__(self):
+        super().__init__()
+        super().initialize()
+        Signal._signalQueue = self
+
+    def functionEvent(self, event):
+        event.call()
+
+    def parseCommandLine(self):
+        pass
+
+    def processEvents(self):
+        pass
+
+
+@pytest.fixture(autouse=True)
+def application():
+    # Since we need to use it more that once, we create the application the first time and use its instance the second
+    application = FixtureApplication.getInstance()
+    if application is None:
+        application = FixtureApplication()
+    return application