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Code Issues 32 Releases Wiki Activity

Rewrote migration autodetector to involve actual computer science.

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Fixes #22605, #22735; also lays the ground for some other fixes.
This commit is contained in:
Andrew Godwin
2014-06-05 23:03:33 -07:00
parent 5826dc5282
commit aa12ea05ce
3 changed files with 631 additions and 298 deletions
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151
tests/migrations/test_autodetector.py
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@@ -43,6 +43,8 @@ class AutodetectorTests(TestCase):
("id", models.AutoField(primary_key=True)),
("publishers", models.ManyToManyField("testapp.Publisher")),
])
author_with_m2m_through = ModelState("testapp", "Author", [("id", models.AutoField(primary_key=True)), ("publishers", models.ManyToManyField("testapp.Publisher", through="testapp.Contract"))])
contract = ModelState("testapp", "Contract", [("id", models.AutoField(primary_key=True)), ("author", models.ForeignKey("testapp.Author")), ("publisher", models.ForeignKey("testapp.Publisher"))])
publisher = ModelState("testapp", "Publisher", [("id", models.AutoField(primary_key=True)), ("name", models.CharField(max_length=100))])
publisher_with_author = ModelState("testapp", "Publisher", [("id", models.AutoField(primary_key=True)), ("author", models.ForeignKey("testapp.Author")), ("name", models.CharField(max_length=100))])
publisher_with_book = ModelState("testapp", "Publisher", [("id", models.AutoField(primary_key=True)), ("author", models.ForeignKey("otherapp.Book")), ("name", models.CharField(max_length=100))])
@@ -64,6 +66,67 @@ class AutodetectorTests(TestCase):
knight = ModelState("eggs", "Knight", [("id", models.AutoField(primary_key=True))])
rabbit = ModelState("eggs", "Rabbit", [("id", models.AutoField(primary_key=True)), ("knight", models.ForeignKey("eggs.Knight")), ("parent", models.ForeignKey("eggs.Rabbit"))], {"unique_together": [("parent", "knight")]})
def repr_changes(self, changes):
output = ""
for app_label, migrations in sorted(changes.items()):
output += " %s:\n" % app_label
for migration in migrations:
output += " %s\n" % migration.name
for operation in migration.operations:
output += " %s\n" % operation
return output
def assertNumberMigrations(self, changes, app_label, number):
if not changes.get(app_label, None):
self.fail("No migrations found for %s\n%s" % (app_label, self.repr_changes(changes)))
if len(changes[app_label]) != number:
self.fail("Incorrect number of migrations (%s) for %s (expected %s)\n%s" % (
len(changes[app_label]),
app_label,
number,
self.repr_changes(changes),
))
def assertOperationTypes(self, changes, app_label, index, types):
if not changes.get(app_label, None):
self.fail("No migrations found for %s\n%s" % (app_label, self.repr_changes(changes)))
if len(changes[app_label]) < index + 1:
self.fail("No migration at index %s for %s\n%s" % (index, app_label, self.repr_changes(changes)))
migration = changes[app_label][index]
real_types = [operation.__class__.__name__ for operation in migration.operations]
if types != real_types:
self.fail("Operation type mismatch for %s.%s (expected %s):\n%s" % (
app_label,
migration.name,
types,
self.repr_changes(changes),
))
def assertOperationAttributes(self, changes, app_label, index, operation_index, **attrs):
if not changes.get(app_label, None):
self.fail("No migrations found for %s\n%s" % (app_label, self.repr_changes(changes)))
if len(changes[app_label]) < index + 1:
self.fail("No migration at index %s for %s\n%s" % (index, app_label, self.repr_changes(changes)))
migration = changes[app_label][index]
if len(changes[app_label]) < index + 1:
self.fail("No operation at index %s for %s.%s\n%s" % (
operation_index,
app_label,
migration.name,
self.repr_changes(changes),
))
operation = migration.operations[operation_index]
for attr, value in attrs.items():
if getattr(operation, attr, None) != value:
self.fail("Attribute mismatch for %s.%s op #%s, %s (expected %r):\n%s" % (
app_label,
migration.name,
operation_index + 1,
attr,
value,
self.repr_changes(changes),
))
def make_project_state(self, model_states):
"Shortcut to make ProjectStates from lists of predefined models"
project_state = ProjectState()
@@ -283,6 +346,9 @@ class AutodetectorTests(TestCase):
def test_fk_dependency(self):
"Tests that having a ForeignKey automatically adds a dependency"
# Make state
# Note that testapp (author) has no dependencies,
# otherapp (book) depends on testapp (author),
# thirdapp (edition) depends on otherapp (book)
before = self.make_project_state([])
after = self.make_project_state([self.author_name, self.book, self.edition])
autodetector = MigrationAutodetector(before, after)
@@ -324,12 +390,15 @@ class AutodetectorTests(TestCase):
self.assertEqual(len(changes['testapp']), 1)
# Right number of actions?
migration = changes['testapp'][0]
self.assertEqual(len(migration.operations), 2)
self.assertEqual(len(migration.operations), 3)
# Right actions?
action = migration.operations[0]
self.assertEqual(action.__class__.__name__, "CreateModel")
action = migration.operations[1]
self.assertEqual(action.__class__.__name__, "CreateModel")
# Third action might vanish one day if the optimizer improves.
action = migration.operations[2]
self.assertEqual(action.__class__.__name__, "AddField")
# Right dependencies?
self.assertEqual(migration.dependencies, [])
@@ -352,10 +421,12 @@ class AutodetectorTests(TestCase):
migration2 = changes['otherapp'][0]
self.assertEqual(len(migration2.operations), 1)
migration3 = changes['otherapp'][1]
self.assertEqual(len(migration2.operations), 1)
self.assertEqual(len(migration3.operations), 1)
# Right actions?
action = migration1.operations[0]
self.assertEqual(action.__class__.__name__, "CreateModel")
self.assertEqual(action.name, "Author")
self.assertEqual(len(action.fields), 3)
action = migration2.operations[0]
self.assertEqual(action.__class__.__name__, "CreateModel")
self.assertEqual(len(action.fields), 2)
@@ -364,8 +435,8 @@ class AutodetectorTests(TestCase):
self.assertEqual(action.name, "author")
# Right dependencies?
self.assertEqual(migration1.dependencies, [("otherapp", "auto_1")])
self.assertEqual(migration2.dependencies, [('testapp', '__first__')])
self.assertEqual(set(migration3.dependencies), set([("otherapp", "auto_1"), ("testapp", "auto_1")]))
self.assertEqual(migration2.dependencies, [])
self.assertEqual(set(migration3.dependencies), set([("testapp", "auto_1"), ("otherapp", "auto_1")]))
def test_same_app_circular_fk_dependency(self):
"""
@@ -378,23 +449,23 @@ class AutodetectorTests(TestCase):
autodetector = MigrationAutodetector(before, after)
changes = autodetector._detect_changes()
# Right number of migrations?
self.assertEqual(len(changes['testapp']), 2)
self.assertEqual(len(changes['testapp']), 1)
# Right number of actions?
migration1 = changes['testapp'][0]
self.assertEqual(len(migration1.operations), 2)
migration2 = changes['testapp'][1]
self.assertEqual(len(migration2.operations), 1)
self.assertEqual(len(migration1.operations), 4)
# Right actions?
action = migration1.operations[0]
self.assertEqual(action.__class__.__name__, "CreateModel")
action = migration1.operations[1]
self.assertEqual(action.__class__.__name__, "CreateModel")
action = migration2.operations[0]
action = migration1.operations[2]
self.assertEqual(action.__class__.__name__, "AddField")
self.assertEqual(action.name, "publisher")
action = migration1.operations[3]
self.assertEqual(action.__class__.__name__, "AddField")
self.assertEqual(action.name, "author")
# Right dependencies?
self.assertEqual(migration1.dependencies, [])
self.assertEqual(migration2.dependencies, [("testapp", "auto_1")])
def test_same_app_circular_fk_dependency_and_unique_together(self):
"""
@@ -408,29 +479,22 @@ class AutodetectorTests(TestCase):
autodetector = MigrationAutodetector(before, after)
changes = autodetector._detect_changes()
# Right number of migrations?
self.assertEqual(len(changes['eggs']), 2)
self.assertEqual(len(changes['eggs']), 1)
# Right number of actions?
migration1 = changes['eggs'][0]
self.assertEqual(len(migration1.operations), 2)
migration2 = changes['eggs'][1]
self.assertEqual(len(migration2.operations), 2)
self.assertEqual(len(migration1.operations), 3)
# Right actions?
action = migration1.operations[0]
self.assertEqual(action.__class__.__name__, "CreateModel")
action = migration1.operations[1]
self.assertEqual(action.__class__.__name__, "CreateModel")
# CreateModel action for Rabbit should not have unique_together now
self.assertEqual(action.name, "Rabbit")
self.assertFalse("unique_together" in action.options)
action = migration2.operations[0]
self.assertEqual(action.__class__.__name__, "AddField")
self.assertEqual(action.name, "parent")
action = migration2.operations[1]
action = migration1.operations[2]
self.assertEqual(action.__class__.__name__, "AlterUniqueTogether")
self.assertEqual(action.name, "rabbit")
# Right dependencies?
self.assertEqual(migration1.dependencies, [])
self.assertEqual(migration2.dependencies, [("eggs", "auto_1")])
def test_unique_together(self):
"Tests unique_together detection"
@@ -670,11 +734,54 @@ class AutodetectorTests(TestCase):
self.assertEqual(len(changes['otherapp']), 1)
# Right number of actions?
migration = changes['otherapp'][0]
self.assertEqual(len(migration.operations), 2)
self.assertEqual(len(migration.operations), 4)
# Right actions in right order?
# The first two are because we can't optimise RemoveField
# into DeleteModel reliably.
action = migration.operations[0]
self.assertEqual(action.__class__.__name__, "RemoveField")
self.assertEqual(action.name, "authors")
self.assertEqual(action.name, "author")
action = migration.operations[1]
self.assertEqual(action.__class__.__name__, "RemoveField")
self.assertEqual(action.name, "book")
action = migration.operations[2]
self.assertEqual(action.__class__.__name__, "RemoveField")
self.assertEqual(action.name, "authors")
action = migration.operations[3]
self.assertEqual(action.__class__.__name__, "DeleteModel")
self.assertEqual(action.name, "Attribution")
def test_m2m_w_through_multistep_remove(self):
"""
A model with a m2m field that specifies a "through" model cannot be removed in the same
migration as that through model as the schema will pass through an inconsistent state.
The autodetector should produce two migrations to avoid this issue.
"""
before = self.make_project_state([self.author_with_m2m_through, self.publisher, self.contract])
after = self.make_project_state([self.publisher])
autodetector = MigrationAutodetector(before, after)
changes = autodetector._detect_changes()
# Right number of migrations?
self.assertNumberMigrations(changes, "testapp", 1)
# Right actions in right order?
self.assertOperationTypes(changes, "testapp", 0, ["RemoveField", "RemoveField", "DeleteModel", "RemoveField", "DeleteModel"])
# Actions touching the right stuff?
self.assertOperationAttributes(changes, "testapp", 0, 0, name="publishers")
self.assertOperationAttributes(changes, "testapp", 0, 1, name="author")
self.assertOperationAttributes(changes, "testapp", 0, 2, name="Author")
self.assertOperationAttributes(changes, "testapp", 0, 3, name="publisher")
self.assertOperationAttributes(changes, "testapp", 0, 4, name="Contract")
def test_non_circular_foreignkey_dependency_removal(self):
"""
If two models with a ForeignKey from one to the other are removed at the same time,
the autodetector should remove them in the correct order.
"""
before = self.make_project_state([self.author_with_publisher, self.publisher_with_author])
after = self.make_project_state([])
autodetector = MigrationAutodetector(before, after)
changes = autodetector._detect_changes()
# Right number of migrations?
self.assertNumberMigrations(changes, "testapp", 1)
# Right actions in right order?
self.assertOperationTypes(changes, "testapp", 0, ["RemoveField", "RemoveField", "DeleteModel", "DeleteModel"])