Implement Migration.run_before (45fa5201) · Commits · Dom Sekotill / django

django/db/migrations/loader.py

+24 −17

Original line number	Diff line number	Diff line
		@@ -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):
		"""

tests/migrations/test_loader.py

+16 −0

Original line number	Diff line number	Diff line
		@@ -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"

tests/migrations/test_migrations_run_before/0001_initial.py

0 → 100644

+20 −0

Original line number	Diff line number	Diff line
		# -- 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)),
		],
		),

		]

tests/migrations/test_migrations_run_before/0002_second.py

0 → 100644

+23 −0

Original line number	Diff line number	Diff line
		# -- 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)),
		],
		)

		]

tests/migrations/test_migrations_run_before/0003_third.py

0 → 100644

+32 −0

Original line number	Diff line number	Diff line
		# -- 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)),
		],
		)

		]