reuse wx.App instance to increase test reliability

gooey/gui/application.py

@@ -18,19 +18,26 @@ from gooey.util.functional import merge
 
 
 def run(build_spec):
-  app, _ = build_app(build_spec)
-  app.MainLoop()
+    app, _ = build_app(build_spec)
+    app.MainLoop()
 
 
 def build_app(build_spec):
-  app = wx.App(False)
-  # use actual program name instead of script file name in macOS menu
-  app.SetAppDisplayName(build_spec['program_name'])
-
-  i18n.load(build_spec['language_dir'], build_spec['language'], build_spec['encoding'])
-  imagesPaths = image_repository.loadImages(build_spec['image_dir'])
-  gapp = GooeyApplication(merge(build_spec, imagesPaths))
-  wx.lib.inspection.InspectionTool().Show()
-  gapp.Show()
-  return (app, gapp)
-
+    app = wx.App(False)
+    return _build_app(build_spec, app)
+
+
+def _build_app(build_spec, app):
+    """
+    Note: this method is broken out with app as
+    an argument to facilitate testing.
+    """
+    # use actual program name instead of script file name in macOS menu
+    app.SetAppDisplayName(build_spec['program_name'])
+
+    i18n.load(build_spec['language_dir'], build_spec['language'], build_spec['encoding'])
+    imagesPaths = image_repository.loadImages(build_spec['image_dir'])
+    gapp = GooeyApplication(merge(build_spec, imagesPaths))
+    # wx.lib.inspection.InspectionTool().Show()
+    gapp.Show()
+    return (app, gapp)

gooey/gui/containers/application.py

@@ -95,8 +95,6 @@ class GooeyApplication(wx.Frame):
                 config.displayErrors()
                 self.Layout()
         
-
-
     def onEdit(self):
         """Return the user to the settings screen for further editing"""
         with transactUI(self):
@@ -144,14 +142,46 @@ class GooeyApplication(wx.Frame):
                     if self.buildSpec.get('show_failure_modal'):
                         wx.CallAfter(modals.showFailure)
 
+    def onCancel(self):
+        """Close the program after confirming
+
+        We treat the behavior of the "cancel" button slightly
+        differently than the general window close X button only
+        because this is 'part of' the form.
+        """
+        if modals.confirmExit():
+            self.onClose()
+
 
     def onStopExecution(self):
         """Displays a scary message and then force-quits the executing
         client code if the user accepts"""
-        if not self.buildSpec['show_stop_warning'] or modals.confirmForceStop():
+        if self.shouldStopExecution():
             self.clientRunner.stop()
 
 
+    def onClose(self, *args, **kwargs):
+        """Stop any actively running client program, cleanup the top
+        level WxFrame and shutdown the current process"""
+        # issue #592 - we need to run the same onStopExecution machinery
+        # when the exit button is clicked to ensure everything is cleaned
+        # up correctly.
+        if self.clientRunner.running():
+            if self.shouldStopExecution():
+                self.clientRunner.stop()
+                self.destroyGooey()
+        else:
+            self.destroyGooey()
+
+
+    def shouldStopExecution(self):
+        return not self.buildSpec['show_stop_warning'] or modals.confirmForceStop()
+
+
+    def destroyGooey(self):
+        self.Destroy()
+        sys.exit()
+
     def fetchExternalUpdates(self):
         """
         !Experimental!
@@ -165,25 +195,6 @@ class GooeyApplication(wx.Frame):
         for config in self.configs:
             config.seedUI(seeds)
 
-
-    def onCancel(self):
-        """Close the program after confirming"""
-        if modals.confirmExit():
-            self.onClose()
-
-
-    def onClose(self, *args, **kwargs):
-        """Stop any actively running client program, cleanup the top
-        level WxFrame and shutdown the current process"""
-        # issue #592 - we need to run the same onStopExecution machinery
-        # when the exit button is clicked to ensure everything is cleaned
-        # up correctly.
-        if self.clientRunner.running():
-            self.onStopExecution()
-        self.Destroy()
-        sys.exit()
-
-
     def layoutComponent(self):
         sizer = wx.BoxSizer(wx.VERTICAL)
         sizer.Add(self.header, 0, wx.EXPAND)

gooey/tests/__init__.py

@@ -0,0 +1,43 @@
+"""
+This weirdness exists to work around a very specific problem
+with testing WX: you can only ever have one App() instance per
+process. I've spent hours and hours trying to work around this and
+figure out how to gracefully destroy and recreate them, but... no dice.
+
+This is echo'd in the docs: https://wxpython.org/Phoenix/docs/html/wx.App.html
+
+Destroying/recreating causes instability in the tests. We can work around that
+by reusing the same App instance across tests and only destroying the top level
+frame (which is fine). However, this causes a new problem: the last test which
+runs will now always fail, cause we're not Destroying the App instance.
+
+Ideal world: UnitTest would expose a global "done" hook regardless of test
+discovery type. That doesn't exist, so the best we can do is use the Module cleanup
+methods. These aren't perfect, but destroying / recreating at the module boundary
+gives slightly more reliable tests. These are picked up by the test runner
+by their existence in the module's globals(). There's no other way to hook
+things together. We need it in every test, and thus... that's the background
+for why this weirdness is going on.
+
+It's a hack around a hack around a problem in Wx.
+
+Usage:
+
+In any tests which use WX, you must import this module's definitions
+into the test's global scope
+
+```
+from gooey.tests import *
+```
+"""
+import wx
+
+app = None
+
+def setUpModule():
+    global app
+    app = wx.App()
+
+def tearDownModule():
+    global app
+    app.Destroy()

gooey/tests/harness.py

@@ -1,24 +1,38 @@
 from contextlib import contextmanager
 
+import time
+from threading import Thread
+
 import wx
 
-from gui import application
+from gooey.gui import application
 from python_bindings.config_generator import create_from_parser
 from python_bindings.gooey_decorator import defaults
 from util.functional import merge
 
 
+
+
 @contextmanager
 def instrumentGooey(parser, **kwargs):
     """
     Context manager used during testing for setup/tear down of the
     WX infrastructure during subTests.
+
+    Weirdness warning: this uses a globally reused wx.App instance.
     """
+    from gooey.tests import app
+    if app == None:
+        raise Exception("App instance has not been created! This is likely due to "
+                        "you forgetting to add the magical import which makes all these "
+                        "tests work. See the module doc in gooey.tests.__init__ for guidance")
     buildspec = create_from_parser(parser, "", **merge(defaults, kwargs))
-    app, gooey = application.build_app(buildspec)
+    app, gooey = application._build_app(buildspec, app)
+    app.SetTopWindow(gooey)
     try:
         yield (app, gooey)
     finally:
         wx.CallAfter(app.ExitMainLoop)
         gooey.Destroy()
-        app.Destroy()
+        app.SetTopWindow(None)
+        del gooey

gooey/tests/test_application.py

@@ -8,11 +8,10 @@ from unittest.mock import MagicMock
 from python_bindings import constants
 from tests.harness import instrumentGooey
 
+from gooey.tests import *
 
 class TestGooeyApplication(unittest.TestCase):
 
-
-
     def testFullscreen(self):
         parser = self.basicParser()
         for shouldShow in [True, False]:
@@ -64,16 +63,14 @@ class TestGooeyApplication(unittest.TestCase):
         """
         parser = self.basicParser()
         with instrumentGooey(parser) as (app, gapp):
-            with patch('gui.containers.application.sys.exit') as exitmock:
-                gapp.clientRunner = MagicMock()
-                gapp.Destroy = MagicMock()
-                # mocking that the user clicks "yes shut down" in the warning modal
-                mockModal.return_value = True
-                gapp.onClose()
-                
-                mockModal.assert_called()
-                gapp.Destroy.assert_called()
-                exitmock.assert_called()
+            gapp.clientRunner = MagicMock()
+            gapp.destroyGooey = MagicMock()
+            # mocking that the user clicks "yes shut down" in the warning modal
+            mockModal.return_value = True
+            gapp.onClose()
+
+            mockModal.assert_called()
+            gapp.destroyGooey.assert_called()
 
 
     def testTerminalColorChanges(self):

gooey/tests/test_argparse_to_json.py

@@ -6,7 +6,7 @@ from argparse import ArgumentParser
 from gooey import GooeyParser
 from gooey.python_bindings import argparse_to_json
 from gooey.util.functional import getin
-
+from gooey.tests import *
 
 class TestArgparse(unittest.TestCase):
 

gooey/tests/test_chooser_results.py

@@ -3,6 +3,8 @@ import os
 import unittest
 
 from gooey.gui.components.widgets.core import chooser
+from gooey.tests import *
+
 
 class MockWxMDD:
     def GetPaths(self):

gooey/tests/test_cmd_args.py

@@ -3,6 +3,8 @@ import unittest
 from gooey import GooeyParser
 from gooey.python_bindings import cmd_args
 from argparse import ArgumentParser
+from gooey.tests import *
+
 
 class TextCommandLine(unittest.TestCase):
 

gooey/tests/test_config_generator.py

@@ -3,7 +3,7 @@ from argparse import ArgumentParser
 
 from python_bindings import constants
 from python_bindings.config_generator import create_from_parser
-
+from gooey.tests import *
 
 class TextConfigGenerator(unittest.TestCase):
 

gooey/tests/test_constraints.py

@@ -1,7 +1,7 @@
 import unittest
 
 from gooey import GooeyParser
-
+from gooey.tests import *
 
 class TestConstraints(unittest.TestCase):
 

gooey/tests/test_dropdown.py

@@ -3,7 +3,7 @@ from argparse import ArgumentParser
 from unittest.mock import patch
 
 from tests.harness import instrumentGooey
-
+from gooey.tests import *
 
 class TestGooeyDropdown(unittest.TestCase):
 

gooey/tests/test_filterable_dropdown.py

@@ -2,8 +2,8 @@ import unittest
 from argparse import ArgumentParser
 from collections import namedtuple
 from unittest.mock import patch
-
 import wx
+from gooey.tests import *
 
 from gooey.tests.harness import instrumentGooey
 from gooey import GooeyParser

gooey/tests/test_header.py

@@ -3,7 +3,7 @@ from argparse import ArgumentParser
 from itertools import *
 
 from tests.harness import instrumentGooey
-
+from gooey.tests import *
 
 class TestGooeyHeader(unittest.TestCase):
 

gooey/tests/test_parent_inheritance.py

@@ -2,7 +2,7 @@ import argparse
 import unittest
 
 from gooey import GooeyParser
-
+from gooey.tests import *
 
 class TestParentInheritance(unittest.TestCase):
 

gooey/tests/test_radiogroup.py

@@ -1,13 +1,13 @@
 import unittest
 
-import wx
-
 from gooey import GooeyParser
+from gooey.tests import *
 from tests.harness import instrumentGooey
 
 
 class TestRadioGroupBehavior(unittest.TestCase):
 
+
     def mutext_group(self, options):
         """
         Basic radio group consisting of two options.

gooey/tests/test_time_remaining.py

@@ -5,6 +5,9 @@ from itertools import *
 
 from tests.harness import instrumentGooey
 
+
+from gooey.tests import *
+
 class TestFooterTimeRemaining(unittest.TestCase):
 
     def make_parser(self):
@@ -18,7 +21,6 @@ class TestFooterTimeRemaining(unittest.TestCase):
 
                     gooeyApp.showConsole()
                     footer = gooeyApp.footer
-                    
 
                     self.assertEqual(
                         footer.time_remaining_text.Shown,

gooey/tests/test_util.py

@@ -1,6 +1,8 @@
 import re
 import unittest
 
+from gooey.tests import *
+
 from gooey.gui.util.time import get_current_time,get_elapsed_time,estimate_time_remaining,format_interval