Add initial test suite for processing algorithm dialog

python/plugins/processing/gui/AlgorithmDialogBase.py

@@ -85,7 +85,7 @@ def pushConsoleInfo(self, msg):
 class AlgorithmDialogBase(BASE, WIDGET):
 
     def __init__(self, alg):
-        super(AlgorithmDialogBase, self).__init__(iface.mainWindow())
+        super(AlgorithmDialogBase, self).__init__(iface.mainWindow() if iface else None)
         self.setupUi(self)
 
         # don't collapse parameters panel

python/plugins/processing/tests/CMakeLists.txt

@@ -6,6 +6,7 @@ PLUGIN_INSTALL(processing tests/testdata ${TEST_DATA_FILES})
 
 IF(ENABLE_TESTS)
   INCLUDE(UsePythonTest)
+  ADD_PYTHON_TEST(ProcessingGuiTest GuiTest.py)
   ADD_PYTHON_TEST(ProcessingParametersTest ParametersTest.py)
   ADD_PYTHON_TEST(ProcessingModelerTest ModelerTest.py)
   ADD_PYTHON_TEST(ProcessingToolsTest ToolsTest.py)

python/plugins/processing/tests/GuiTest.py

@@ -0,0 +1,45 @@
+# -*- coding: utf-8 -*-
+
+"""
+***************************************************************************
+    ParametersTest
+    ---------------------
+    Date                 : August 2017
+    Copyright            : (C) 2017 by Nyall Dawson
+    Email                : nyall dot dawson at gmail dot com
+***************************************************************************
+*                                                                         *
+*   This program is free software; you can redistribute it and/or modify  *
+*   it under the terms of the GNU General Public License as published by  *
+*   the Free Software Foundation; either version 2 of the License, or     *
+*   (at your option) any later version.                                   *
+*                                                                         *
+***************************************************************************
+"""
+
+__author__ = 'Nyall Dawson'
+__date__ = 'August 2017'
+__copyright__ = '(C) 2017, Nyall Dawson'
+
+# This will get replaced with a git SHA1 when you do a git archive
+
+__revision__ = '$Format:%H$'
+
+from qgis.testing import start_app, unittest
+from qgis.core import QgsApplication
+
+from processing.gui.AlgorithmDialog import AlgorithmDialog
+
+start_app()
+
+
+class AlgorithmDialogTest(unittest.TestCase):
+
+    def testCreation(self):
+        alg = QgsApplication.processingRegistry().algorithmById('native:centroids')
+        a = AlgorithmDialog(alg)
+        self.assertEqual(a.mainWidget().alg, alg)
+
+
+if __name__ == '__main__':
+    unittest.main()