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django/tests/migrations/test_optimizer.py
Hasan Ramezani 7c18b22e2f Fixed #32256 -- Fixed migration optimization crash when swapping field names.
This disables optimization of RenameField operation when an old field
name is referenced in subsequent operations.

Co-authored-by: InvalidInterrupt <InvalidInterrupt@users.noreply.github.com>
2021-02-19 11:19:01 +01:00

886 lines
33 KiB
Python

from django.db import migrations, models
from django.db.migrations import operations
from django.db.migrations.optimizer import MigrationOptimizer
from django.db.migrations.serializer import serializer_factory
from django.test import SimpleTestCase
from .models import EmptyManager, UnicodeModel
class OptimizerTests(SimpleTestCase):
"""
Tests the migration autodetector.
"""
def optimize(self, operations, app_label):
"""
Handy shortcut for getting results + number of loops
"""
optimizer = MigrationOptimizer()
return optimizer.optimize(operations, app_label), optimizer._iterations
def serialize(self, value):
return serializer_factory(value).serialize()[0]
def assertOptimizesTo(self, operations, expected, exact=None, less_than=None, app_label=None):
result, iterations = self.optimize(operations, app_label or 'migrations')
result = [self.serialize(f) for f in result]
expected = [self.serialize(f) for f in expected]
self.assertEqual(expected, result)
if exact is not None and iterations != exact:
raise self.failureException(
"Optimization did not take exactly %s iterations (it took %s)" % (exact, iterations)
)
if less_than is not None and iterations >= less_than:
raise self.failureException(
"Optimization did not take less than %s iterations (it took %s)" % (less_than, iterations)
)
def assertDoesNotOptimize(self, operations, **kwargs):
self.assertOptimizesTo(operations, operations, **kwargs)
def test_none_app_label(self):
optimizer = MigrationOptimizer()
with self.assertRaisesMessage(TypeError, 'app_label must be a str'):
optimizer.optimize([], None)
def test_single(self):
"""
The optimizer does nothing on a single operation,
and that it does it in just one pass.
"""
self.assertOptimizesTo(
[migrations.DeleteModel("Foo")],
[migrations.DeleteModel("Foo")],
exact=1,
)
def test_create_delete_model(self):
"""
CreateModel and DeleteModel should collapse into nothing.
"""
self.assertOptimizesTo(
[
migrations.CreateModel("Foo", [("name", models.CharField(max_length=255))]),
migrations.DeleteModel("Foo"),
],
[],
)
def test_create_rename_model(self):
"""
CreateModel should absorb RenameModels.
"""
managers = [('objects', EmptyManager())]
self.assertOptimizesTo(
[
migrations.CreateModel(
name="Foo",
fields=[("name", models.CharField(max_length=255))],
options={'verbose_name': 'Foo'},
bases=(UnicodeModel,),
managers=managers,
),
migrations.RenameModel("Foo", "Bar"),
],
[
migrations.CreateModel(
"Bar",
[("name", models.CharField(max_length=255))],
options={'verbose_name': 'Foo'},
bases=(UnicodeModel,),
managers=managers,
)
],
)
def test_rename_model_self(self):
"""
RenameModels should absorb themselves.
"""
self.assertOptimizesTo(
[
migrations.RenameModel("Foo", "Baa"),
migrations.RenameModel("Baa", "Bar"),
],
[
migrations.RenameModel("Foo", "Bar"),
],
)
def test_create_alter_model_options(self):
self.assertOptimizesTo(
[
migrations.CreateModel('Foo', fields=[]),
migrations.AlterModelOptions(name='Foo', options={'verbose_name_plural': 'Foozes'}),
],
[
migrations.CreateModel('Foo', fields=[], options={'verbose_name_plural': 'Foozes'}),
]
)
def test_create_model_and_remove_model_options(self):
self.assertOptimizesTo(
[
migrations.CreateModel(
'MyModel',
fields=[],
options={'verbose_name': 'My Model'},
),
migrations.AlterModelOptions('MyModel', options={}),
],
[migrations.CreateModel('MyModel', fields=[])],
)
self.assertOptimizesTo(
[
migrations.CreateModel(
'MyModel',
fields=[],
options={
'verbose_name': 'My Model',
'verbose_name_plural': 'My Model plural',
},
),
migrations.AlterModelOptions(
'MyModel',
options={'verbose_name': 'My Model'},
),
],
[
migrations.CreateModel(
'MyModel',
fields=[],
options={'verbose_name': 'My Model'},
),
],
)
def _test_create_alter_foo_delete_model(self, alter_foo):
"""
CreateModel, AlterModelTable, AlterUniqueTogether/AlterIndexTogether/
AlterOrderWithRespectTo, and DeleteModel should collapse into nothing.
"""
self.assertOptimizesTo(
[
migrations.CreateModel("Foo", [("name", models.CharField(max_length=255))]),
migrations.AlterModelTable("Foo", "woohoo"),
alter_foo,
migrations.DeleteModel("Foo"),
],
[],
)
def test_create_alter_unique_delete_model(self):
self._test_create_alter_foo_delete_model(migrations.AlterUniqueTogether("Foo", [["a", "b"]]))
def test_create_alter_index_delete_model(self):
self._test_create_alter_foo_delete_model(migrations.AlterIndexTogether("Foo", [["a", "b"]]))
def test_create_alter_owrt_delete_model(self):
self._test_create_alter_foo_delete_model(migrations.AlterOrderWithRespectTo("Foo", "a"))
def _test_alter_alter_model(self, alter_foo, alter_bar):
"""
Two AlterUniqueTogether/AlterIndexTogether/AlterOrderWithRespectTo
should collapse into the second.
"""
self.assertOptimizesTo(
[
alter_foo,
alter_bar,
],
[
alter_bar,
],
)
def test_alter_alter_table_model(self):
self._test_alter_alter_model(
migrations.AlterModelTable("Foo", "a"),
migrations.AlterModelTable("Foo", "b"),
)
def test_alter_alter_unique_model(self):
self._test_alter_alter_model(
migrations.AlterUniqueTogether("Foo", [["a", "b"]]),
migrations.AlterUniqueTogether("Foo", [["a", "c"]]),
)
def test_alter_alter_index_model(self):
self._test_alter_alter_model(
migrations.AlterIndexTogether("Foo", [["a", "b"]]),
migrations.AlterIndexTogether("Foo", [["a", "c"]]),
)
def test_alter_alter_owrt_model(self):
self._test_alter_alter_model(
migrations.AlterOrderWithRespectTo("Foo", "a"),
migrations.AlterOrderWithRespectTo("Foo", "b"),
)
def test_optimize_through_create(self):
"""
We should be able to optimize away create/delete through a create or delete
of a different model, but only if the create operation does not mention the model
at all.
"""
# These should work
self.assertOptimizesTo(
[
migrations.CreateModel("Foo", [("name", models.CharField(max_length=255))]),
migrations.CreateModel("Bar", [("size", models.IntegerField())]),
migrations.DeleteModel("Foo"),
],
[
migrations.CreateModel("Bar", [("size", models.IntegerField())]),
],
)
self.assertOptimizesTo(
[
migrations.CreateModel("Foo", [("name", models.CharField(max_length=255))]),
migrations.CreateModel("Bar", [("size", models.IntegerField())]),
migrations.DeleteModel("Bar"),
migrations.DeleteModel("Foo"),
],
[],
)
self.assertOptimizesTo(
[
migrations.CreateModel("Foo", [("name", models.CharField(max_length=255))]),
migrations.CreateModel("Bar", [("size", models.IntegerField())]),
migrations.DeleteModel("Foo"),
migrations.DeleteModel("Bar"),
],
[],
)
# Operations should be optimized if the FK references a model from the
# other app.
self.assertOptimizesTo(
[
migrations.CreateModel("Foo", [("name", models.CharField(max_length=255))]),
migrations.CreateModel("Bar", [("other", models.ForeignKey("testapp.Foo", models.CASCADE))]),
migrations.DeleteModel("Foo"),
],
[
migrations.CreateModel("Bar", [("other", models.ForeignKey("testapp.Foo", models.CASCADE))]),
],
app_label="otherapp",
)
# But it shouldn't work if a FK references a model with the same
# app_label.
self.assertDoesNotOptimize(
[
migrations.CreateModel('Foo', [('name', models.CharField(max_length=255))]),
migrations.CreateModel('Bar', [('other', models.ForeignKey('Foo', models.CASCADE))]),
migrations.DeleteModel('Foo'),
],
)
self.assertDoesNotOptimize(
[
migrations.CreateModel("Foo", [("name", models.CharField(max_length=255))]),
migrations.CreateModel("Bar", [("other", models.ForeignKey("testapp.Foo", models.CASCADE))]),
migrations.DeleteModel("Foo"),
],
app_label="testapp",
)
# This should not work - bases should block it
self.assertDoesNotOptimize(
[
migrations.CreateModel('Foo', [('name', models.CharField(max_length=255))]),
migrations.CreateModel('Bar', [('size', models.IntegerField())], bases=('Foo',)),
migrations.DeleteModel('Foo'),
],
)
self.assertDoesNotOptimize(
[
migrations.CreateModel("Foo", [("name", models.CharField(max_length=255))]),
migrations.CreateModel("Bar", [("size", models.IntegerField())], bases=("testapp.Foo",)),
migrations.DeleteModel("Foo"),
],
app_label='testapp',
)
# The same operations should be optimized if app_label and none of
# bases belong to that app.
self.assertOptimizesTo(
[
migrations.CreateModel("Foo", [("name", models.CharField(max_length=255))]),
migrations.CreateModel("Bar", [("size", models.IntegerField())], bases=("testapp.Foo",)),
migrations.DeleteModel("Foo"),
],
[
migrations.CreateModel("Bar", [("size", models.IntegerField())], bases=("testapp.Foo",)),
],
app_label="otherapp",
)
# But it shouldn't work if some of bases belongs to the specified app.
self.assertDoesNotOptimize(
[
migrations.CreateModel("Foo", [("name", models.CharField(max_length=255))]),
migrations.CreateModel("Bar", [("size", models.IntegerField())], bases=("testapp.Foo",)),
migrations.DeleteModel("Foo"),
],
app_label="testapp",
)
self.assertOptimizesTo(
[
migrations.CreateModel('Book', [('name', models.CharField(max_length=255))]),
migrations.CreateModel('Person', [('name', models.CharField(max_length=255))]),
migrations.AddField('book', 'author', models.ForeignKey('test_app.Person', models.CASCADE)),
migrations.CreateModel('Review', [('book', models.ForeignKey('test_app.Book', models.CASCADE))]),
migrations.CreateModel('Reviewer', [('name', models.CharField(max_length=255))]),
migrations.AddField('review', 'reviewer', models.ForeignKey('test_app.Reviewer', models.CASCADE)),
migrations.RemoveField('book', 'author'),
migrations.DeleteModel('Person'),
],
[
migrations.CreateModel('Book', [('name', models.CharField(max_length=255))]),
migrations.CreateModel('Reviewer', [('name', models.CharField(max_length=255))]),
migrations.CreateModel('Review', [
('book', models.ForeignKey('test_app.Book', models.CASCADE)),
('reviewer', models.ForeignKey('test_app.Reviewer', models.CASCADE)),
]),
],
app_label='test_app',
)
def test_create_model_add_field(self):
"""
AddField should optimize into CreateModel.
"""
managers = [('objects', EmptyManager())]
self.assertOptimizesTo(
[
migrations.CreateModel(
name="Foo",
fields=[("name", models.CharField(max_length=255))],
options={'verbose_name': 'Foo'},
bases=(UnicodeModel,),
managers=managers,
),
migrations.AddField("Foo", "age", models.IntegerField()),
],
[
migrations.CreateModel(
name="Foo",
fields=[
("name", models.CharField(max_length=255)),
("age", models.IntegerField()),
],
options={'verbose_name': 'Foo'},
bases=(UnicodeModel,),
managers=managers,
),
],
)
def test_create_model_reordering(self):
"""
AddField optimizes into CreateModel if it's a FK to a model that's
between them (and there's no FK in the other direction), by changing
the order of the CreateModel operations.
"""
self.assertOptimizesTo(
[
migrations.CreateModel('Foo', [('name', models.CharField(max_length=255))]),
migrations.CreateModel('Link', [('url', models.TextField())]),
migrations.AddField('Foo', 'link', models.ForeignKey('migrations.Link', models.CASCADE)),
],
[
migrations.CreateModel('Link', [('url', models.TextField())]),
migrations.CreateModel('Foo', [
('name', models.CharField(max_length=255)),
('link', models.ForeignKey('migrations.Link', models.CASCADE))
]),
],
)
def test_create_model_reordering_circular_fk(self):
"""
CreateModel reordering behavior doesn't result in an infinite loop if
there are FKs in both directions.
"""
self.assertOptimizesTo(
[
migrations.CreateModel('Bar', [('url', models.TextField())]),
migrations.CreateModel('Foo', [('name', models.CharField(max_length=255))]),
migrations.AddField('Bar', 'foo_fk', models.ForeignKey('migrations.Foo', models.CASCADE)),
migrations.AddField('Foo', 'bar_fk', models.ForeignKey('migrations.Bar', models.CASCADE)),
],
[
migrations.CreateModel('Foo', [('name', models.CharField(max_length=255))]),
migrations.CreateModel('Bar', [
('url', models.TextField()),
('foo_fk', models.ForeignKey('migrations.Foo', models.CASCADE)),
]),
migrations.AddField('Foo', 'bar_fk', models.ForeignKey('migrations.Bar', models.CASCADE)),
],
)
def test_create_model_no_reordering_for_unrelated_fk(self):
"""
CreateModel order remains unchanged if the later AddField operation
isn't a FK between them.
"""
self.assertDoesNotOptimize(
[
migrations.CreateModel('Foo', [('name', models.CharField(max_length=255))]),
migrations.CreateModel('Link', [('url', models.TextField())]),
migrations.AddField('Other', 'link', models.ForeignKey('migrations.Link', models.CASCADE)),
],
)
def test_create_model_no_reordering_of_inherited_model(self):
"""
A CreateModel that inherits from another isn't reordered to avoid
moving it earlier than its parent CreateModel operation.
"""
self.assertOptimizesTo(
[
migrations.CreateModel('Other', [('foo', models.CharField(max_length=255))]),
migrations.CreateModel('ParentModel', [('bar', models.CharField(max_length=255))]),
migrations.CreateModel(
'ChildModel',
[('baz', models.CharField(max_length=255))],
bases=('migrations.parentmodel',),
),
migrations.AddField('Other', 'fk', models.ForeignKey('migrations.ChildModel', models.CASCADE)),
],
[
migrations.CreateModel('ParentModel', [('bar', models.CharField(max_length=255))]),
migrations.CreateModel(
'ChildModel',
[('baz', models.CharField(max_length=255))],
bases=('migrations.parentmodel',),
),
migrations.CreateModel(
'Other', [
('foo', models.CharField(max_length=255)),
('fk', models.ForeignKey('migrations.ChildModel', models.CASCADE)),
]
),
],
)
def test_create_model_add_field_not_through_m2m_through(self):
"""
AddField should NOT optimize into CreateModel if it's an M2M using a
through that's created between them.
"""
self.assertDoesNotOptimize(
[
migrations.CreateModel('Employee', []),
migrations.CreateModel('Employer', []),
migrations.CreateModel('Employment', [
('employee', models.ForeignKey('migrations.Employee', models.CASCADE)),
('employment', models.ForeignKey('migrations.Employer', models.CASCADE)),
]),
migrations.AddField(
'Employer', 'employees', models.ManyToManyField(
'migrations.Employee', through='migrations.Employment',
)
),
],
)
def test_create_model_alter_field(self):
"""
AlterField should optimize into CreateModel.
"""
managers = [('objects', EmptyManager())]
self.assertOptimizesTo(
[
migrations.CreateModel(
name="Foo",
fields=[("name", models.CharField(max_length=255))],
options={'verbose_name': 'Foo'},
bases=(UnicodeModel,),
managers=managers,
),
migrations.AlterField("Foo", "name", models.IntegerField()),
],
[
migrations.CreateModel(
name="Foo",
fields=[
("name", models.IntegerField()),
],
options={'verbose_name': 'Foo'},
bases=(UnicodeModel,),
managers=managers,
),
],
)
def test_create_model_rename_field(self):
"""
RenameField should optimize into CreateModel.
"""
managers = [('objects', EmptyManager())]
self.assertOptimizesTo(
[
migrations.CreateModel(
name="Foo",
fields=[("name", models.CharField(max_length=255))],
options={'verbose_name': 'Foo'},
bases=(UnicodeModel,),
managers=managers,
),
migrations.RenameField("Foo", "name", "title"),
],
[
migrations.CreateModel(
name="Foo",
fields=[
("title", models.CharField(max_length=255)),
],
options={'verbose_name': 'Foo'},
bases=(UnicodeModel,),
managers=managers,
),
],
)
def test_add_field_rename_field(self):
"""
RenameField should optimize into AddField
"""
self.assertOptimizesTo(
[
migrations.AddField("Foo", "name", models.CharField(max_length=255)),
migrations.RenameField("Foo", "name", "title"),
],
[
migrations.AddField("Foo", "title", models.CharField(max_length=255)),
],
)
def test_alter_field_rename_field(self):
"""
RenameField should optimize to the other side of AlterField,
and into itself.
"""
self.assertOptimizesTo(
[
migrations.AlterField("Foo", "name", models.CharField(max_length=255)),
migrations.RenameField("Foo", "name", "title"),
migrations.RenameField("Foo", "title", "nom"),
],
[
migrations.RenameField("Foo", "name", "nom"),
migrations.AlterField("Foo", "nom", models.CharField(max_length=255)),
],
)
def test_swapping_fields_names(self):
self.assertDoesNotOptimize(
[
migrations.CreateModel(
'MyModel',
[
('field_a', models.IntegerField()),
('field_b', models.IntegerField()),
],
),
migrations.RunPython(migrations.RunPython.noop),
migrations.RenameField('MyModel', 'field_a', 'field_c'),
migrations.RenameField('MyModel', 'field_b', 'field_a'),
migrations.RenameField('MyModel', 'field_c', 'field_b'),
],
)
def test_create_model_remove_field(self):
"""
RemoveField should optimize into CreateModel.
"""
managers = [('objects', EmptyManager())]
self.assertOptimizesTo(
[
migrations.CreateModel(
name="Foo",
fields=[
("name", models.CharField(max_length=255)),
("age", models.IntegerField()),
],
options={'verbose_name': 'Foo'},
bases=(UnicodeModel,),
managers=managers,
),
migrations.RemoveField("Foo", "age"),
],
[
migrations.CreateModel(
name="Foo",
fields=[
("name", models.CharField(max_length=255)),
],
options={'verbose_name': 'Foo'},
bases=(UnicodeModel,),
managers=managers,
),
],
)
def test_add_field_alter_field(self):
"""
AlterField should optimize into AddField.
"""
self.assertOptimizesTo(
[
migrations.AddField("Foo", "age", models.IntegerField()),
migrations.AlterField("Foo", "age", models.FloatField(default=2.4)),
],
[
migrations.AddField("Foo", name="age", field=models.FloatField(default=2.4)),
],
)
def test_add_field_delete_field(self):
"""
RemoveField should cancel AddField
"""
self.assertOptimizesTo(
[
migrations.AddField("Foo", "age", models.IntegerField()),
migrations.RemoveField("Foo", "age"),
],
[],
)
def test_alter_field_delete_field(self):
"""
RemoveField should absorb AlterField
"""
self.assertOptimizesTo(
[
migrations.AlterField("Foo", "age", models.IntegerField()),
migrations.RemoveField("Foo", "age"),
],
[
migrations.RemoveField("Foo", "age"),
],
)
def _test_create_alter_foo_field(self, alter):
"""
CreateModel, AlterFooTogether/AlterOrderWithRespectTo followed by an
add/alter/rename field should optimize to CreateModel with options.
"""
option_value = getattr(alter, alter.option_name)
options = {alter.option_name: option_value}
# AddField
self.assertOptimizesTo(
[
migrations.CreateModel("Foo", [
("a", models.IntegerField()),
("b", models.IntegerField()),
]),
alter,
migrations.AddField("Foo", "c", models.IntegerField()),
],
[
migrations.CreateModel("Foo", [
("a", models.IntegerField()),
("b", models.IntegerField()),
("c", models.IntegerField()),
], options=options),
],
)
# AlterField
self.assertOptimizesTo(
[
migrations.CreateModel("Foo", [
("a", models.IntegerField()),
("b", models.IntegerField()),
]),
alter,
migrations.AlterField("Foo", "b", models.CharField(max_length=255)),
],
[
migrations.CreateModel("Foo", [
("a", models.IntegerField()),
("b", models.CharField(max_length=255)),
], options=options),
],
)
self.assertOptimizesTo(
[
migrations.CreateModel("Foo", [
("a", models.IntegerField()),
("b", models.IntegerField()),
("c", models.IntegerField()),
]),
alter,
migrations.AlterField("Foo", "c", models.CharField(max_length=255)),
],
[
migrations.CreateModel("Foo", [
("a", models.IntegerField()),
("b", models.IntegerField()),
("c", models.CharField(max_length=255)),
], options=options),
],
)
# RenameField
if isinstance(option_value, str):
renamed_options = {alter.option_name: 'c'}
else:
renamed_options = {
alter.option_name: {
tuple('c' if value == 'b' else value for value in item) for item in option_value
}
}
self.assertOptimizesTo(
[
migrations.CreateModel("Foo", [
("a", models.IntegerField()),
("b", models.IntegerField()),
]),
alter,
migrations.RenameField("Foo", "b", "c"),
],
[
migrations.CreateModel("Foo", [
("a", models.IntegerField()),
("c", models.IntegerField()),
], options=renamed_options),
],
)
self.assertOptimizesTo(
[
migrations.CreateModel("Foo", [
("a", models.IntegerField()),
("b", models.IntegerField()),
]),
alter,
migrations.RenameField("Foo", "b", "x"),
migrations.RenameField("Foo", "x", "c"),
],
[
migrations.CreateModel("Foo", [
("a", models.IntegerField()),
("c", models.IntegerField()),
], options=renamed_options),
],
)
self.assertOptimizesTo(
[
migrations.CreateModel("Foo", [
("a", models.IntegerField()),
("b", models.IntegerField()),
("c", models.IntegerField()),
]),
alter,
migrations.RenameField("Foo", "c", "d"),
],
[
migrations.CreateModel("Foo", [
("a", models.IntegerField()),
("b", models.IntegerField()),
("d", models.IntegerField()),
], options=options),
],
)
# RemoveField
if isinstance(option_value, str):
removed_options = None
else:
removed_options = {
alter.option_name: {
tuple(value for value in item if value != 'b') for item in option_value
}
}
self.assertOptimizesTo(
[
migrations.CreateModel("Foo", [
("a", models.IntegerField()),
("b", models.IntegerField()),
]),
alter,
migrations.RemoveField("Foo", "b"),
],
[
migrations.CreateModel("Foo", [
("a", models.IntegerField()),
], options=removed_options),
]
)
self.assertOptimizesTo(
[
migrations.CreateModel("Foo", [
("a", models.IntegerField()),
("b", models.IntegerField()),
("c", models.IntegerField()),
]),
alter,
migrations.RemoveField("Foo", "c"),
],
[
migrations.CreateModel("Foo", [
("a", models.IntegerField()),
("b", models.IntegerField()),
], options=options),
],
)
def test_create_alter_unique_field(self):
self._test_create_alter_foo_field(migrations.AlterUniqueTogether("Foo", [["a", "b"]]))
def test_create_alter_index_field(self):
self._test_create_alter_foo_field(migrations.AlterIndexTogether("Foo", [["a", "b"]]))
def test_create_alter_owrt_field(self):
self._test_create_alter_foo_field(migrations.AlterOrderWithRespectTo("Foo", "b"))
def test_optimize_through_fields(self):
"""
field-level through checking is working. This should manage to collapse
model Foo to nonexistence, and model Bar to a single IntegerField
called "width".
"""
self.assertOptimizesTo(
[
migrations.CreateModel("Foo", [("name", models.CharField(max_length=255))]),
migrations.CreateModel("Bar", [("size", models.IntegerField())]),
migrations.AddField("Foo", "age", models.IntegerField()),
migrations.AddField("Bar", "width", models.IntegerField()),
migrations.AlterField("Foo", "age", models.IntegerField()),
migrations.RenameField("Bar", "size", "dimensions"),
migrations.RemoveField("Foo", "age"),
migrations.RenameModel("Foo", "Phou"),
migrations.RemoveField("Bar", "dimensions"),
migrations.RenameModel("Phou", "Fou"),
migrations.DeleteModel("Fou"),
],
[
migrations.CreateModel("Bar", [("width", models.IntegerField())]),
],
)
def test_optimize_elidable_operation(self):
elidable_operation = operations.base.Operation()
elidable_operation.elidable = True
self.assertOptimizesTo(
[
elidable_operation,
migrations.CreateModel("Foo", [("name", models.CharField(max_length=255))]),
elidable_operation,
migrations.CreateModel("Bar", [("size", models.IntegerField())]),
elidable_operation,
migrations.RenameModel("Foo", "Phou"),
migrations.DeleteModel("Bar"),
elidable_operation,
],
[
migrations.CreateModel("Phou", [("name", models.CharField(max_length=255))]),
],
)