Support more compatibility import rewrites

[UnknownPlatypus]

Description

I noticed while browsing django codebase for warnings.warn that some (rather old) compatibility imports were not supported by django-upgrade.

Do you think it could be a valuable addition ?

I was thinking of using a similar pattern to anthony's compatibility import plugin by keeping a mapping of django-version -> import (similar to the current REWRITES mappings) while still relying on the django-upgrade update_import_modules for the actual fixing.

This could maybe lead to a small performance improvement too by grouping the existing fixer that are mostly checking the same things. As always, I'm happy to send a PR!

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Here are the compatibility imports that I think are not currently covered.

Imports

--target-version 2.0

• django.utils.decorators.ContextDecorator -> contextlib.ContextDecorator: Undocumented - source

--target-version 1.11

• django.test.runner.setup_databases() -> django.test.utils.setup_databases() : release note - source - RemovedInDjango21

--target-version 1.10

• django.contrib.staticfiles.templatetags.staticfiles.static() -> django.templatetags.static.static(): release note - source 1.10 - RemovedInDjango30
• django.core.urlresolvers.* -> django.urls.*: release note - source - RemovedInDjango20

--target-version 1.9

• django.db.backends.postgresql_psycopg2.* -> django.db.backends.postgresql.*: release note - source - RemovedInDjango30.
• django.forms.extras.SelectDateWidget -> django.forms.widgets.SelectDateWidget: release note - source - RemovedInDjango20

--target-version 1.8

• django.core.context_processors.* -> django.template.context_processors.*: release note - source - RemovedInDjango110
• django.db.models.sql.aggregates -> django.db.models.aggregates: release note - source - RemovedInDjango110

--target-version 1.6

• django.template.base.Context -> django.template.context.Context: Same for BaseContext, ContextPopException and RequestContext: release note - source - RemovedInDjango31

--target-version 1.1

• django.contrib.admin.ACTION_CHECKBOX_NAME -> django.contrib.admin.helpers.ACTION_CHECKBOX_NAME : release note - source - RemovedInDjango31

[adamchainz]

Whilst most of the imports you’ve found are from pretty old versions, I think it could be valuable to group the pure import move fixers in one. I think it would be best if you could make a first PR that groups them, before we add any new ones.

Also I wouldn’t want to add any older versions than we already support (1.7), just for a few import changes.

[UnknownPlatypus]

I think it would be best if you could make a first PR that groups them, before we add any new ones.

Makes sense, will start with the grouping then.

Also I wouldn’t want to add any older versions than we already support (1.7), just for a few import changes.

yeah, most of them could be grouped into existing target-version maybe.