Commit 799e81ef authored by Matthew Schinckel's avatar Matthew Schinckel Committed by Tim Graham
Browse files

[1.9.x] Fixed #26475 -- Added functools.partial() support to migrations autodetector. 

Backport of 5402f3ab from master
parent f5b8e9b2

django/db/migrations/autodetector.py

+3 −0
Original line number Diff line number Diff line 
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):

docs/releases/1.9.6.txt

+3 −0
Original line number Diff line number Diff line
@@ -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`).

tests/migrations/test_autodetector.py

+54 −0
Original line number Diff line number Diff line 
# -*- 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):