Add skip_runtime_checks so that you can lint django/run parts of it without having access to sharded environments (#90)

* Update decorators.py

* Update decorators.py

* Update config.yml

* Update test_decorators.py

* Update CHANGES.md

* Update setup.py

Author: JBKahn

.circleci/config.yml

@@ -82,8 +82,7 @@ jobs:
       - checkout
       - python/load-cache:
           key: python-cache-1-11
-      - python/install-deps:
-          local: false
+      - python/install-deps
       - python/save-cache:
           key: python-cache-1-11
       - run:

CHANGES.md

@@ -1,6 +1,11 @@
 Changelog
 =========
 
+5.2.0 (January 27th 2020)
+------------------
+
+- Add `skip_runtime_checks` to `model_config` to allow for use of linting tools where sharded databases aren't setup.
+
 5.1.0 (December 10th 2019)
 ------------------
 

django_sharding_library/decorators.py

@@ -20,7 +20,7 @@ def configure(cls):
     return configure
 
 
-def model_config(shard_group=None, database=None):
+def model_config(shard_group=None, database=None, skip_runtime_checks=False):
     """
     A decorator for marking a model as being either sharded or stored on a
     particular database. When sharding, it does some verification to ensure
@@ -34,14 +34,14 @@ def configure(cls):
             raise ShardedModelInitializationException('The model should be either sharded or stored on a database in the `model_config` decorator is used.')
 
         if database:
-            if database not in settings.DATABASES or settings.DATABASES[database].get('PRIMARY'):
+            if (database not in settings.DATABASES or settings.DATABASES[database].get('PRIMARY')) and skip_runtime_checks is False:
                 raise NonExistentDatabaseException(
                     'Unable to place {} in {} as that is not an existing primary database in the system.'.format(cls._meta.model_name, database)
                 )
             setattr(cls, 'django_sharding__database', database)
 
         postgres_shard_id_fields = list(filter(lambda field: issubclass(type(field), BasePostgresShardGeneratedIDField), cls._meta.fields))
-        if postgres_shard_id_fields:
+        if postgres_shard_id_fields and skip_runtime_checks is False:
             database_dicts = [settings.DATABASES[database]] if database else [db_settings for db, db_settings in
                                                                               iteritems(settings.DATABASES) if
                                                                               db_settings["SHARD_GROUP"] == shard_group]

setup.py

@@ -1,6 +1,6 @@
 from setuptools import setup, find_packages
 
-version = '5.1.0'
+version = '5.2.0'
 
 
 def get_requirements(file_path):

tests/test_decorators.py

@@ -95,6 +95,10 @@ def test_cannot_place_database_on_non_existant_db(self):
             class ShardedTestModelIDsTwo(TableStrategyModel):
                 pass
 
+        @model_config(database='i_do_not_exist', skip_runtime_checks=True)
+        class ShardedTestModelIDsTwo(TableStrategyModel):
+            pass
+
     def test_puts_database_name_on_model_stored_on_another_database(self):
         @model_config(database='app_shard_002')
         class ShardedTestModelIDsThree(TableStrategyModel):