Commit 8c4ca16c authored by Loic Bistuer's avatar Loic Bistuer
Browse files

Fixed #23621 -- Warn for duplicate models when a module is reloaded. 

Previously a RuntimeError was raised every time two models clashed
in the app registry. This prevented reloading a module in a REPL;
while it's not recommended to do so, we decided not to forbid this
use-case by turning the error into a warning.

Thanks @dfunckt and Sergey Pashinin for the initial patches.
parent 4bf86d25

django/apps/registry.py

+9 −3
Original line number Diff line number Diff line
@@ -208,6 +208,12 @@ class Apps(object): 
        model_name = model._meta.model_name

        app_models = self.all_models[app_label]

        if model_name in app_models:

            if (model.__name__ == app_models[model_name].__name__ and

                    model.__module__ == app_models[model_name].__module__):

                warnings.warn(

                    "Model '%s.%s' was already registered." % (model_name, app_label),

                    RuntimeWarning, stacklevel=2)

            else:

                raise RuntimeError(

                    "Conflicting '%s' models in application '%s': %s and %s." %

                    (model_name, app_label, app_models[model_name], model))

tests/apps/tests.py

+36 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ from __future__ import unicode_literals 
import os

import sys

from unittest import skipUnless

import warnings



from django.apps import apps, AppConfig

from django.apps.registry import Apps
@@ -208,6 +209,41 @@ class AppsTests(TestCase): 
            apps.get_model("apps", "SouthPonies")

        self.assertEqual(new_apps.get_model("apps", "SouthPonies"), temp_model)



    def test_model_clash(self):

        """

        Test for behavior when two models clash in the app registry.

        """

        new_apps = Apps(["apps"])

        meta_contents = {

            'app_label': "apps",

            'apps': new_apps,

        }



        body = {}

        body['Meta'] = type(str("Meta"), tuple(), meta_contents)

        body['__module__'] = TotallyNormal.__module__

        type(str("SouthPonies"), (models.Model,), body)



        # When __name__ and __module__ match we assume the module

        # was reloaded and issue a warning. This use-case is

        # useful for REPL. Refs #23621.

        body = {}

        body['Meta'] = type(str("Meta"), tuple(), meta_contents)

        body['__module__'] = TotallyNormal.__module__

        with warnings.catch_warnings(record=True) as w:

            type(str("SouthPonies"), (models.Model,), body)

            self.assertEqual(len(w), 1)

            self.assertTrue(issubclass(w[-1].category, RuntimeWarning))

            self.assertEqual(str(w[-1].message), "Model 'southponies.apps' was already registered.")



        # If it doesn't appear to be a reloaded module then we expect

        # a RuntimeError.

        body = {}

        body['Meta'] = type(str("Meta"), tuple(), meta_contents)

        body['__module__'] = TotallyNormal.__module__ + '.whatever'

        with six.assertRaisesRegex(self, RuntimeError,

                "Conflicting 'southponies' models in application 'apps':.*"):

            type(str("SouthPonies"), (models.Model,), body)



class Stub(object):

    def __init__(self, **kwargs):