From 45fa5201874df2883be003b7ed29ac14751431b8 Mon Sep 17 00:00:00 2001
From: Chris Beaven <smileychris@gmail.com>
Date: Thu, 29 May 2014 22:30:47 +1200
Subject: [PATCH] Implement Migration.run_before
This attribute (used for reverse dependencies) was previously declared
and mentioned in the code, but never actually used.
---
django/db/migrations/loader.py | 41 +++++++++++--------
tests/migrations/test_loader.py | 16 ++++++++
.../0001_initial.py | 20 +++++++++
.../test_migrations_run_before/0002_second.py | 23 +++++++++++
.../test_migrations_run_before/0003_third.py | 32 +++++++++++++++
.../test_migrations_run_before/__init__.py | 0
6 files changed, 115 insertions(+), 17 deletions(-)
create mode 100644 tests/migrations/test_migrations_run_before/0001_initial.py
create mode 100644 tests/migrations/test_migrations_run_before/0002_second.py
create mode 100644 tests/migrations/test_migrations_run_before/0003_third.py
create mode 100644 tests/migrations/test_migrations_run_before/__init__.py
diff --git a/django/db/migrations/loader.py b/django/db/migrations/loader.py
index 661f74ff97..bb41c46be1 100644
--- a/django/db/migrations/loader.py
+++ b/django/db/migrations/loader.py
@@ -134,6 +134,25 @@ class MigrationLoader(object):
else:
return self.disk_migrations[results[0]]
+ def check_key(self, key, current_app):
+ if key[1] != "__first__" or key in self.graph:
+ return key
+ # Special-case __first__, which means "the first migration" for
+ # migrated apps, and is ignored for unmigrated apps. It allows
+ # makemigrations to declare dependencies on apps before they even have
+ # migrations.
+ if key[0] == current_app:
+ # Ignore __first__ references to the same app (#22325)
+ return
+ if key[0] in self.unmigrated_apps:
+ # This app isn't migrated, but something depends on it.
+ # The models will get auto-added into the state, though
+ # so we're fine.
+ return
+ if key[0] in self.migrated_apps:
+ return list(self.graph.root_nodes(key[0]))[0]
+ raise ValueError("Dependency on unknown app %s" % key[0])
+
def build_graph(self):
"""
Builds a migration dependency graph using both the disk and database.
@@ -196,25 +215,13 @@ class MigrationLoader(object):
self.graph.add_node(key, migration)
for key, migration in normal.items():
for parent in migration.dependencies:
- # Special-case __first__, which means "the first migration" for
- # migrated apps, and is ignored for unmigrated apps. It allows
- # makemigrations to declare dependencies on apps before they
- # even have migrations.
- if parent[1] == "__first__" and parent not in self.graph:
- if parent[0] == key[0]:
- # Ignore __first__ references to the same app (#22325)
- continue
- elif parent[0] in self.unmigrated_apps:
- # This app isn't migrated, but something depends on it.
- # The models will get auto-added into the state, though
- # so we're fine.
- continue
- elif parent[0] in self.migrated_apps:
- parent = list(self.graph.root_nodes(parent[0]))[0]
- else:
- raise ValueError("Dependency on unknown app %s" % parent[0])
+ parent = self.check_key(parent, key[0])
if parent is not None:
self.graph.add_dependency(key, parent)
+ for child in migration.run_before:
+ child = self.check_key(child, key[0])
+ if child is not None:
+ self.graph.add_dependency(child, key)
def detect_conflicts(self):
"""
diff --git a/tests/migrations/test_loader.py b/tests/migrations/test_loader.py
index 34bc340495..5f307a1816 100644
--- a/tests/migrations/test_loader.py
+++ b/tests/migrations/test_loader.py
@@ -102,6 +102,22 @@ class LoaderTests(TestCase):
["id", "user"]
)
+ @override_settings(MIGRATION_MODULES={"migrations": "migrations.test_migrations_run_before"})
+ def test_run_before(self):
+ """
+ Makes sure the loader uses Migration.run_before.
+ """
+ # Load and test the plan
+ migration_loader = MigrationLoader(connection)
+ self.assertEqual(
+ migration_loader.graph.forwards_plan(("migrations", "0002_second")),
+ [
+ ("migrations", "0001_initial"),
+ ("migrations", "0003_third"),
+ ("migrations", "0002_second"),
+ ],
+ )
+
@override_settings(MIGRATION_MODULES={"migrations": "migrations.test_migrations"})
def test_name_match(self):
"Tests prefix name matching"
diff --git a/tests/migrations/test_migrations_run_before/0001_initial.py b/tests/migrations/test_migrations_run_before/0001_initial.py
new file mode 100644
index 0000000000..7d44a8d789
--- /dev/null
+++ b/tests/migrations/test_migrations_run_before/0001_initial.py
@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+ operations = [
+
+ migrations.CreateModel(
+ "Salamander",
+ [
+ ("id", models.AutoField(primary_key=True)),
+ ("size", models.IntegerField(default=0)),
+ ("silly_field", models.BooleanField(default=False)),
+ ],
+ ),
+
+ ]
diff --git a/tests/migrations/test_migrations_run_before/0002_second.py b/tests/migrations/test_migrations_run_before/0002_second.py
new file mode 100644
index 0000000000..c0e03b4620
--- /dev/null
+++ b/tests/migrations/test_migrations_run_before/0002_second.py
@@ -0,0 +1,23 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+ dependencies = [
+ ("migrations", "0001_initial"),
+ ]
+
+ operations = [
+
+ migrations.CreateModel(
+ "Book",
+ [
+ ("id", models.AutoField(primary_key=True)),
+ ("author", models.ForeignKey("migrations.Author", null=True)),
+ ],
+ )
+
+ ]
diff --git a/tests/migrations/test_migrations_run_before/0003_third.py b/tests/migrations/test_migrations_run_before/0003_third.py
new file mode 100644
index 0000000000..d5c098c730
--- /dev/null
+++ b/tests/migrations/test_migrations_run_before/0003_third.py
@@ -0,0 +1,32 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+ """
+ This is a wee bit crazy, but it's just to show that run_before works.
+ """
+
+ dependencies = [
+ ("migrations", "0001_initial"),
+ ]
+
+ run_before = [
+ ("migrations", "0002_second"),
+ ]
+
+ operations = [
+
+ migrations.CreateModel(
+ "Author",
+ [
+ ("id", models.AutoField(primary_key=True)),
+ ("name", models.CharField(max_length=255)),
+ ("slug", models.SlugField(null=True)),
+ ("age", models.IntegerField(default=0)),
+ ],
+ )
+
+ ]
diff --git a/tests/migrations/test_migrations_run_before/__init__.py b/tests/migrations/test_migrations_run_before/__init__.py
new file mode 100644
index 0000000000..e69de29bb2