Merge branch '251-we-should-systematically-enforce-model-constraints-on-save' into 'django'

Resolve "we should systematically enforce model constraints on .save()"

Closes #251

See merge request !128

django/allgo/main/models.py

@@ -32,8 +32,29 @@ def generate_token(length=32):
     """
     return get_random_string(length)
 
+class BaseModel(models.Model):
+    """Base model for all allgo models
 
-class TimeStampModel(models.Model):
+    This base class overrides .save() to enforce validation of the model
+    constraints before creating or updating an entry.
+
+    The validation is automatically peformed unless `force_insert` or
+    `force_update` is true.
+
+    see also:
+    - https://www.xormedia.com/django-model-validation-on-save/
+    - https://en.wikipedia.org/wiki/Fail-fast
+    """
+    def save(self, force_insert=False, force_update=False, **kw):
+        if not (force_insert or force_update):
+            self.full_clean()
+        super().save(force_insert, force_update, **kw)
+
+    class Meta:
+        abstract = True
+
+
+class TimeStampModel(BaseModel):
     """
     An abstract base class model that provides self-updating ``created_at`` and
     ``updated_at`` fields.
@@ -46,7 +67,7 @@ class TimeStampModel(models.Model):
         abstract = True
 
 
-class AllgoUser(models.Model):
+class AllgoUser(BaseModel):
     """
     Class linked to the Django user management. If there is a need to add a
     field related to a user, it should be added here and not in the auth_user
@@ -74,7 +95,7 @@ class AllgoUser(models.Model):
         return [a.docker_name for a in Webapp.objects.filter(user_id=self.user.id)]
 
 
-class DockerOs(models.Model):
+class DockerOs(BaseModel):
     """
     Contains the different Operating Systems that a user can choose from to
     build its container.