fix: prepare email without template, but with context (#468)

post_office/models.py

@@ -104,7 +104,7 @@ def prepare_email_message(self):
         if get_override_recipients():
             self.to = get_override_recipients()
 
-        if self.context is not None:
+        if self.template is not None and self.context is not None:
             engine = get_template_engine()
             subject = engine.from_string(self.template.subject).render(self.context)
             plaintext_message = engine.from_string(self.template.content).render(self.context)

post_office/tests/test_models.py

@@ -65,6 +65,20 @@ def test_email_message_render(self):
         self.assertEqual(message.body, 'Content test')
         self.assertEqual(message.alternatives[0][0], 'HTML test')
 
+    def test_email_message_prepare_without_template_and_with_context(self):
+        """
+        Ensure Email instance without template but with context is properly prepared.
+        """
+        context = {'name': 'test'}
+        email = Email.objects.create(to=['[email protected]'], template=None,
+                                     subject='Subject test', message='Content test',
+                                     html_message='HTML test',
+                                     from_email='[email protected]', context=context)
+        message = email.email_message()
+        self.assertEqual(message.subject, 'Subject test')
+        self.assertEqual(message.body, 'Content test')
+        self.assertEqual(message.alternatives[0][0], 'HTML test')
+
     def test_dispatch(self):
         """
         Ensure that email.dispatch() actually sends out the email