Add tests for Workflow and Task creation and linking, and change related_names to be more usable

wagtail/core/models.py

@@ -358,7 +358,8 @@ class Page(AbstractPage, index.Indexed, ClusterableModel, metaclass=PageBase):
         related_name='pages',
         verbose_name=_('workflow'),
         on_delete=models.SET_NULL,
-        null=True
+        null=True,
+        blank=True,
     )
 
     search_fields = [
@@ -2391,8 +2392,8 @@ class GroupCollectionPermission(models.Model):
 
 
 class WorkflowTask(models.Model):
-    workflow = models.ForeignKey('Workflow', on_delete=models.CASCADE, verbose_name=_('workflow'))
-    task = models.ForeignKey('Task', on_delete=models.CASCADE, verbose_name=_('task'))
+    workflow = models.ForeignKey('Workflow', on_delete=models.CASCADE, verbose_name=_('workflow_tasks'))
+    task = models.ForeignKey('Task', on_delete=models.CASCADE, verbose_name=_('task'), related_name='workflow_tasks')
     sort_order = models.PositiveIntegerField(verbose_name=_('priority'))
 
     class Meta:
@@ -2452,7 +2453,7 @@ class Task(models.Model):
 
 class Workflow(models.Model):
     name = models.CharField(max_length=255, verbose_name=_('name'))
-    tasks = models.ManyToManyField(Task, through=WorkflowTask)
+    tasks = models.ManyToManyField(Task, through=WorkflowTask, related_name='workflows')
 
     def __str__(self):
         return self.name

wagtail/core/tests/test_workflow.py

@@ -0,0 +1,28 @@
+from django.test import TestCase
+
+from wagtail.core.models import Task, Workflow, WorkflowTask
+
+
+class TestPageQuerySet(TestCase):
+    fixtures = ['test.json']
+
+    def test_create_workflow(self):
+        # test creating and retrieving an empty workflow from the db
+        test_workflow = Workflow(name='test_workflow')
+        test_workflow.save()
+        retrieved_workflow = Workflow.objects.get(id=test_workflow.id)
+        self.assertEqual(retrieved_workflow.name, 'test_workflow')
+
+    def test_create_task(self):
+        # test creating and retrieving a base task from the db
+        test_task = Task(name='test_task')
+        test_task.save()
+        retrieved_task = Task.objects.get(id=test_task.id)
+        self.assertEqual(retrieved_task.name, 'test_task')
+
+    def test_add_task_to_workflow(self):
+        workflow = Workflow.objects.create(name='test_workflow')
+        task = Task.objects.create(name='test_task')
+        workflow_task = WorkflowTask.objects.create(workflow=workflow, task=task, sort_order=1)
+        self.assertIn(task, workflow.tasks.all())
+        self.assertIn(workflow, task.workflows.all())