Add tests for scheduling

Closes #2523

InvenTree/plugin/samples/integration/test_scheduled_task.py

@@ -0,0 +1,29 @@
+""" Unit tests for scheduled tasks"""
+
+from django.test import TestCase
+
+from plugin import registry
+
+
+class ScheduledTaskPluginTests(TestCase):
+    """ Tests for ScheduledTaskPlugin """
+
+    def test_function(self):
+        """check if the scheduling works"""
+        # The plugin should be defined
+        self.assertIn('schedule', registry.plugins)
+        plg = registry.plugins['schedule']
+        self.assertTrue(plg)
+
+        # check that the built-in function is running
+        plg.member_func()
+
+        # check that the tasks are defined
+        self.assertEqual(plg.get_task_names(), ['plugin.schedule.member', 'plugin.schedule.hello', 'plugin.schedule.world'])
+
+        # register
+        plg.register_tasks()
+        # check that schedule was registers
+        from django_q.models import Schedule
+        scheduled_plugin_tasks = Schedule.objects.filter(name__istartswith="plugin.")
+        self.assertEqual(len(scheduled_plugin_tasks), 3)