Refs #36383 -- Extended DeconstructibleSerializer to support non-identifier keyword arguments.

In Python, keyword arguments must normally be valid identifiers (i.e.,
variable names that follow Python's naming rules). However, Python dicts
can have keys that aren't valid identifiers, like "foo-bar" or "123foo".

This commit ensures that keyword arguments that are nt valid
identifiers, are properly handled when deconstructing an object.

Author: adamchainz

django/db/migrations/serializer.py

@@ -102,10 +102,20 @@ def serialize_deconstructed(path, args, kwargs):
             arg_string, arg_imports = serializer_factory(arg).serialize()
             strings.append(arg_string)
             imports.update(arg_imports)
+        non_ident_kwargs = {}
         for kw, arg in sorted(kwargs.items()):
-            arg_string, arg_imports = serializer_factory(arg).serialize()
-            imports.update(arg_imports)
-            strings.append("%s=%s" % (kw, arg_string))
+            if kw.isidentifier():
+                arg_string, arg_imports = serializer_factory(arg).serialize()
+                imports.update(arg_imports)
+                strings.append("%s=%s" % (kw, arg_string))
+            else:
+                non_ident_kwargs[kw] = arg
+        if non_ident_kwargs:
+            # Serialize non-identifier keyword arguments as a dict.
+            kw_string, kw_imports = serializer_factory(non_ident_kwargs).serialize()
+            strings.append(f"**{kw_string}")
+            imports.update(kw_imports)
+
         return "%s(%s)" % (name, ", ".join(strings)), imports
 
     @staticmethod

docs/releases/6.0.txt

@@ -181,6 +181,9 @@ Migrations
 
 * Migrations now support serialization of :class:`zoneinfo.ZoneInfo` instances.
 
+* Serialization of deconstructible objects now supports keyword arguments with
+  names that are not valid Python identifiers.
+
 Models
 ~~~~~~
 

docs/spelling_wordlist

@@ -113,6 +113,7 @@ databrowse
 datafile
 datetimes
 declaratively
+deconstructible
 deduplicates
 deduplication
 deepcopy

tests/migrations/test_writer.py

@@ -41,6 +41,13 @@ def deconstruct(self):
         return ("DeconstructibleInstances", [], {})
 
 
+@deconstructible
+class DeconstructibleArbitrary:
+    def __init__(self, *args, **kwargs):
+        self.args = args
+        self.kwargs = kwargs
+
+
 class Money(decimal.Decimal):
     def deconstruct(self):
         return (
@@ -1143,6 +1150,24 @@ def test_deconstruct_class_arguments(self):
             "models.CharField(default=migrations.test_writer.DeconstructibleInstances)",
         )
 
+    def test_serialize_non_identifier_keyword_args(self):
+        instance = DeconstructibleArbitrary(
+            **{"kebab-case": 1, "my_list": [1, 2, 3], "123foo": {"456bar": set()}},
+            regular="kebab-case",
+            **{"simple": 1, "complex": 3.1416},
+        )
+        string, imports = MigrationWriter.serialize(instance)
+        self.assertEqual(
+            string,
+            "migrations.test_writer.DeconstructibleArbitrary(complex=3.1416, "
+            "my_list=[1, 2, 3], regular='kebab-case', simple=1, "
+            "**{'123foo': {'456bar': set()}, 'kebab-case': 1})",
+        )
+        self.assertEqual(imports, {"import migrations.test_writer"})
+        result = self.serialize_round_trip(instance)
+        self.assertEqual(result.args, instance.args)
+        self.assertEqual(result.kwargs, instance.kwargs)
+
     def test_register_serializer(self):
         class ComplexSerializer(BaseSerializer):
             def serialize(self):