diff --git a/atdb/taskdatabase/tests/test_models_joins.py b/atdb/taskdatabase/tests/test_models_joins.py
new file mode 100644
index 0000000000000000000000000000000000000000..a540ab527d0d2107d481e3e13e71ba99e8d54c8f
--- /dev/null
+++ b/atdb/taskdatabase/tests/test_models_joins.py
@@ -0,0 +1,54 @@
+from django.test import TestCase
+import json
+
+from taskdatabase.models import Workflow,Task
+
+
+class TestJoinedTasks(TestCase):
+
+    @classmethod
+    def setUpTestData(cls):
+
+        # Set up non-modified objects used by all test methods
+        workflow = Workflow()
+        workflow.save()
+
+        # create a list of Tasks
+        Task.objects.get_or_create(sas_id=1, status='stored')
+        Task.objects.get_or_create(sas_id=2, status='stored')
+        Task.objects.get_or_create(sas_id=3, status='defined')
+
+
+    def test_add_input_tasks_to_task(self):
+        output_task = Task.objects.get(sas_id=1)
+        input_task_1 = Task.objects.get(sas_id=2)
+        input_task_2 = Task.objects.get(sas_id=3)
+        output_task.joined_input_tasks.set([input_task_1,input_task_2])
+        output_task.save()
+
+        # count number of input asks
+        count_input_tasks = output_task.joined_input_tasks.count()
+        self.assertEqual(count_input_tasks,2)
+
+
+    def test_join_status_none(self):
+        output_task = Task.objects.get(sas_id=1)
+        input_task_1 = Task.objects.get(sas_id=2) # stored
+        input_task_2 = Task.objects.get(sas_id=3) # defined
+        output_task.joined_input_tasks.set([input_task_1,input_task_2])
+        output_task.save()
+
+        # one input task on stored, and on on defined, should give: None
+
+        self.assertEqual(output_task.joined_status,None)
+
+
+    def test_join_status_stored(self):
+        output_task = Task.objects.get(sas_id=3)
+        input_task_1 = Task.objects.get(sas_id=2)  # stored
+        input_task_2 = Task.objects.get(sas_id=1)  # stored
+        output_task.joined_input_tasks.set([input_task_1, input_task_2])
+        output_task.save()
+
+        # two input tasks 'stored', should give: 'stored'
+        self.assertEqual(output_task.joined_status, "stored")
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