Refs #36438 -- Made FieldOperation.references_field() detect references in GeneratedField.expression.

Thanks to Simon Charette for the suggestion and review.

django/db/migrations/operations/fields.py

@@ -1,5 +1,5 @@
 from django.db.migrations.utils import field_references
-from django.db.models import NOT_PROVIDED
+from django.db.models import NOT_PROVIDED, Model
 from django.utils.copy import replace
 from django.utils.functional import cached_property
 
@@ -49,12 +49,19 @@ class FieldOperation(Operation):
         if model_name_lower == self.model_name_lower:
             if name == self.name:
                 return True
-            elif (
+            if self.field:
-                self.field
+                if (
-                and hasattr(self.field, "from_fields")
+                    hasattr(self.field, "from_fields")
-                and name in self.field.from_fields
+                    and name in self.field.from_fields
-            ):
+                ):
-                return True
+                    return True
+                elif self.field.generated and any(
+                    field_name == name
+                    for field_name, *_ in Model._get_expr_references(
+                        self.field.expression
+                    )
+                ):
+                    return True
         # Check if this operation remotely references the field.
         if self.field is None:
             return False

tests/migrations/test_operations.py

@@ -6842,6 +6842,21 @@ class FieldOperationTests(SimpleTestCase):
             operation.references_field("Through", "second", "migrations"), True
         )
 
+    def test_references_field_by_generated_field(self):
+        operation = FieldOperation(
+            "Model",
+            "field",
+            models.GeneratedField(
+                expression=F("foo") + F("bar"),
+                output_field=models.IntegerField(),
+                db_persist=True,
+            ),
+        )
+        self.assertIs(operation.references_field("Model", "foo", "migrations"), True)
+        self.assertIs(operation.references_field("Model", "bar", "migrations"), True)
+        self.assertIs(operation.references_field("Model", "alien", "migrations"), False)
+        self.assertIs(operation.references_field("Other", "foo", "migrations"), False)
+
 
 class BaseOperationTests(SimpleTestCase):
     def test_formatted_description_no_category(self):