Refactor ready_for_train in repository update

bothub/common/models.py

@@ -449,15 +449,24 @@ def requirements_to_train(self):
 
     @property
     def ready_for_train(self):
-        last_trained_update = self.repository.last_trained_update(
-            language=self.language)
-        if last_trained_update:
-            if last_trained_update.use_language_model_featurizer is not \
+        if self.training_started_at:
+            return False
+
+        previous_update = self.repository.updates.filter(
+            language=self.language,
+            by__isnull=False,
+            training_started_at__isnull=False,
+            created_at__lt=self.created_at).first()
+
+        if previous_update:
+            if previous_update.use_language_model_featurizer is not \
                self.repository.use_language_model_featurizer:
                 return True
-            if last_trained_update.use_competing_intents is not \
+            if previous_update.use_competing_intents is not \
                self.repository.use_competing_intents:
                 return True
+            if previous_update.failed_at:
+                return True
         return len(self.requirements_to_train) is 0
 
     def validate_init_train(self, by=None):

bothub/common/tests.py

@@ -752,6 +752,12 @@ def test_be_true_when_deleted_example(self):
         self.example_1.delete()
         self.assertTrue(self.repository.ready_for_train)
 
+    def test_last_train_failed(self):
+        current_update = self.repository.current_update()
+        current_update.start_training(self.owner)
+        current_update.train_fail()
+        self.assertTrue(self.repository.current_update().ready_for_train)
+
 
 class RepositoryUpdateReadyForTrain(TestCase):
     def setUp(self):