Allow to run App&GUI without entering the main event loop

aqt/__init__.py

@@ -233,11 +233,14 @@ def run():
                              "Please notify support of this error:\n\n"+
                              traceback.format_exc())
 
-def _run():
+def _run(argv=None, exec=True):
     global mw
 
+    if argv is None:
+        argv = sys.argv
+
     # parse args
-    opts, args = parseArgs(sys.argv)
+    opts, args = parseArgs(argv)
     opts.base = opts.base or ""
     opts.profile = opts.profile or ""
 
@@ -250,7 +253,7 @@ def _run():
     QCoreApplication.setAttribute(Qt.AA_EnableHighDpiScaling)
 
     # create the app
-    app = AnkiApp(sys.argv)
+    app = AnkiApp(argv)
     QCoreApplication.setApplicationName("Anki")
     if app.secondInstance():
         # we've signaled the primary instance, so we should close
@@ -285,4 +288,7 @@ environment points to a valid, writable folder.""")
     # load the main window
     import aqt.main
     mw = aqt.main.AnkiQt(app, pm, args)
-    app.exec_()
+    if exec:
+        app.exec()
+    else:
+        return app

tests/test_run.py

@@ -0,0 +1,42 @@
+# coding: utf-8
+from contextlib import contextmanager
+
+import aqt
+from aqt import _run
+from aqt.profiles import ProfileManager
+
+
+@contextmanager
+def temporaryUser(name="__Temporary Test User__"):
+
+    pm = ProfileManager(base="")
+
+    if name in pm.profiles():
+        raise Exception(f"Could not create a temporary user with name {name}")
+
+    pm.create(name)
+    pm.name = name
+
+    yield name
+
+    pm.remove(name)
+
+def test_run():
+
+    # we need a new user for the test
+    with temporaryUser() as name:
+        app = _run(argv=["anki", "-p", name], exec=False)
+        assert app
+
+    aqt.mw.cleanupAndExit()
+
+    # clean up what was spoiled
+    aqt.mw = None
+
+    # remove hooks added during app initialization
+    from anki import hooks
+    hooks._hooks = {}
+
+    # test_nextIvl will fail on some systems if the locales are not restored
+    import locale
+    locale.setlocale(locale.LC_ALL, locale.getdefaultlocale())