From 5402f3ab09413a571fd9d3aa27f6c76ec42ff891 Mon Sep 17 00:00:00 2001
From: Matthew Schinckel <matt@schinckel.net>
Date: Mon, 18 Apr 2016 11:25:15 +0930
Subject: [PATCH] Fixed #26475 -- Added functools.partial() support to
migrations autodetector.
---
django/db/migrations/autodetector.py | 3 ++
docs/releases/1.9.6.txt | 3 ++
tests/migrations/test_autodetector.py | 54 +++++++++++++++++++++++++++
3 files changed, 60 insertions(+)
diff --git a/django/db/migrations/autodetector.py b/django/db/migrations/autodetector.py
index 943bd35d34..96aa230b24 100644
--- a/django/db/migrations/autodetector.py
+++ b/django/db/migrations/autodetector.py
@@ -1,6 +1,7 @@
from __future__ import unicode_literals
import datetime
+import functools
import re
from itertools import chain
@@ -63,6 +64,8 @@ class MigrationAutodetector(object):
key: self.deep_deconstruct(value)
for key, value in obj.items()
}
+ elif isinstance(obj, functools.partial):
+ return (obj.func, self.deep_deconstruct(obj.args), self.deep_deconstruct(obj.keywords))
elif isinstance(obj, COMPILED_REGEX_TYPE):
return RegexObject(obj)
elif isinstance(obj, type):
diff --git a/docs/releases/1.9.6.txt b/docs/releases/1.9.6.txt
index c22e99f48e..8b48f803c7 100644
--- a/docs/releases/1.9.6.txt
+++ b/docs/releases/1.9.6.txt
@@ -15,3 +15,6 @@ Bugfixes
* Fixed ``TimeField`` microseconds round-tripping on MySQL and SQLite
(:ticket:`26498`).
+
+* Prevented ``makemigrations`` from generating infinite migrations for a model
+ field that references a ``functools.partial`` (:ticket:`26475`).
diff --git a/tests/migrations/test_autodetector.py b/tests/migrations/test_autodetector.py
index ba9b4c8caa..25b6a3190b 100644
--- a/tests/migrations/test_autodetector.py
+++ b/tests/migrations/test_autodetector.py
@@ -1,4 +1,5 @@
# -*- coding: utf-8 -*-
+import functools
import re
from django.apps import apps
@@ -657,6 +658,59 @@ class AutodetectorTests(TestCase):
self.assertOperationTypes(changes, 'testapp', 0, ["AlterField"])
self.assertOperationAttributes(changes, "testapp", 0, 0, name="name", preserve_default=True)
+ def test_supports_functools_partial(self):
+ def _content_file_name(instance, filename, key, **kwargs):
+ return '{}/{}'.format(instance, filename)
+
+ def content_file_name(key, **kwargs):
+ return functools.partial(_content_file_name, key, **kwargs)
+
+ # An unchanged partial reference.
+ before = self.make_project_state([ModelState("testapp", "Author", [
+ ("id", models.AutoField(primary_key=True)),
+ ("file", models.FileField(max_length=200, upload_to=content_file_name('file'))),
+ ])])
+ after = self.make_project_state([ModelState("testapp", "Author", [
+ ("id", models.AutoField(primary_key=True)),
+ ("file", models.FileField(max_length=200, upload_to=content_file_name('file'))),
+ ])])
+ autodetector = MigrationAutodetector(before, after)
+ changes = autodetector._detect_changes()
+ self.assertNumberMigrations(changes, 'testapp', 0)
+
+ # A changed partial reference.
+ args_changed = self.make_project_state([ModelState("testapp", "Author", [
+ ("id", models.AutoField(primary_key=True)),
+ ("file", models.FileField(max_length=200, upload_to=content_file_name('other-file'))),
+ ])])
+ autodetector = MigrationAutodetector(before, args_changed)
+ changes = autodetector._detect_changes()
+ self.assertNumberMigrations(changes, 'testapp', 1)
+ self.assertOperationTypes(changes, 'testapp', 0, ['AlterField'])
+ # Can't use assertOperationFieldAttributes because we need the
+ # deconstructed version, i.e., the exploded func/args/keywords rather
+ # than the partial: we don't care if it's not the same instance of the
+ # partial, only if it's the same source function, args, and keywords.
+ value = changes['testapp'][0].operations[0].field.upload_to
+ self.assertEqual(
+ (_content_file_name, ('other-file',), {}),
+ (value.func, value.args, value.keywords)
+ )
+
+ kwargs_changed = self.make_project_state([ModelState("testapp", "Author", [
+ ("id", models.AutoField(primary_key=True)),
+ ("file", models.FileField(max_length=200, upload_to=content_file_name('file', spam='eggs'))),
+ ])])
+ autodetector = MigrationAutodetector(before, kwargs_changed)
+ changes = autodetector._detect_changes()
+ self.assertNumberMigrations(changes, 'testapp', 1)
+ self.assertOperationTypes(changes, 'testapp', 0, ['AlterField'])
+ value = changes['testapp'][0].operations[0].field.upload_to
+ self.assertEqual(
+ (_content_file_name, ('file',), {'spam': 'eggs'}),
+ (value.func, value.args, value.keywords)
+ )
+
@mock.patch('django.db.migrations.questioner.MigrationQuestioner.ask_not_null_alteration',
side_effect=AssertionError("Should not have prompted for not null addition"))
def test_alter_field_to_not_null_with_default(self, mocked_ask_method):