Fix STORAGES fixer when only one defined (#376)

Co-authored-by: Adam Johnson <[email protected]>

CHANGELOG.rst

@@ -2,6 +2,10 @@
 Changelog
 =========
 
+* Fix bug in ``STORAGES`` fixer when only one of ``DEFAULT_FILE_STORAGE`` or ``STATICFILES_STORAGE`` was defined.
+
+ Thanks to Bruno Alla in `PR #376 <https:/adamchainz/django-upgrade/pull/376>`__.
+
 1.14.0 (2023-06-14)
 -------------------
 

src/django_upgrade/fixers/settings_storages.py

@@ -33,6 +33,11 @@
  "DEFAULT_FILE_STORAGE": "default",
  "STATICFILES_STORAGE": "staticfiles",
 }
+# Keep initial values from Django if one isn't defined
+INITIAL_VALUES = {
+ "default": "django.core.files.storage.FileSystemStorage",
+ "staticfiles": "django.contrib.staticfiles.storage.StaticFilesStorage",
+}
 
 
 class SettingsDetails:
@@ -138,5 +143,16 @@ def replace_storages(
  " },",
  ]
  )
+ elif not details.settings_star_import:
+ new_name = NAME_MAP[name]
+ initial_value = INITIAL_VALUES[new_name]
+ src_fragments.extend(
+ [
+ f' "{new_name}": {{',
+ f' "BACKEND": "{initial_value}",',
+ " },",
+ ]
+ )
+
  src_fragments.append("}\n")
  insert(tokens, i, new_src="\n".join(src_fragments))

tests/fixers/test_settings_storages.py

@@ -97,7 +97,7 @@ def test_setting_exists():
  )
 
 
-def test_one():
+def test_default_only():
  check_transformed(
  """\
  DEFAULT_FILE_STORAGE = "example.backend"
@@ -107,6 +107,29 @@ def test_one():
  "default": {
  "BACKEND": "example.backend",
  },
+ "staticfiles": {
+ "BACKEND": "django.contrib.staticfiles.storage.StaticFilesStorage",
+ },
+ }
+ """,
+ settings,
+ filename="settings.py",
+ )
+
+
+def test_static_only():
+ check_transformed(
+ """\
+ STATICFILES_STORAGE = "example.other.backend"
+ """,
+ """\
+ STORAGES = {
+ "default": {
+ "BACKEND": "django.core.files.storage.FileSystemStorage",
+ },
+ "staticfiles": {
+ "BACKEND": "example.other.backend",
+ },
  }
  """,
  settings,
@@ -166,6 +189,9 @@ def test_retains_quoting():
  "default": {
  "BACKEND": 'example.backend',
  },
+ "staticfiles": {
+ "BACKEND": "django.contrib.staticfiles.storage.StaticFilesStorage",
+ },
  }
  """,
  settings,
@@ -185,6 +211,9 @@ def test_star_import_not_settings():
  "default": {
  "BACKEND": "example.backend",
  },
+ "staticfiles": {
+ "BACKEND": "django.contrib.staticfiles.storage.StaticFilesStorage",
+ },
  }
  """,
  settings,