✨ Refactor Annotated[..., Field()]

bump_pydantic/codemods/field.py

@@ -43,6 +43,20 @@
     ]
 )
 
+ANN_ASSIGN_WITH_FIELD = m.AnnAssign(
+    value=m.Call(func=m.Name("Field")),
+) | m.AnnAssign(
+    annotation=m.Annotation(
+        annotation=m.Subscript(
+            slice=[
+                m.ZeroOrMore(),
+                m.SubscriptElement(slice=m.Index(value=m.Call(func=m.Name("Field")))),
+                m.ZeroOrMore(),
+            ]
+        )
+    )
+)
+
 
 class FieldCodemod(VisitorBasedCodemodCommand):
     def __init__(self, context: CodemodContext) -> None:
@@ -60,12 +74,12 @@ def leave_field_import(self, original_node: cst.Module, updated_node: cst.Module
         self.has_field_import = False
         return updated_node
 
-    @m.visit(m.AnnAssign(value=m.Call(func=m.Name("Field"))))
+    @m.visit(ANN_ASSIGN_WITH_FIELD)
     def visit_field_assign(self, node: cst.AnnAssign) -> None:
         self.inside_field_assign = True
         self._const: Union[cst.Arg, None] = None
 
-    @m.leave(m.AnnAssign(value=m.Call(func=m.Name("Field"))))
+    @m.leave(ANN_ASSIGN_WITH_FIELD)
     def leave_field_assign(self, original_node: cst.AnnAssign, updated_node: cst.AnnAssign) -> cst.AnnAssign:
         self.inside_field_assign = False
 
@@ -124,10 +138,12 @@ def leave_field_call(self, original_node: cst.Call, updated_node: cst.Call) -> c
 
     source = textwrap.dedent(
         """
+        from typing import Annotated
+
         from pydantic import BaseModel, Field
 
         class A(BaseModel):
-            a: List[str] = Field(..., description="My description", min_items=1)
+            a: Annotated[List[str], Field(..., description="My description", min_items=1)]
         """
     )
     console.print(source)

tests/unit/test_field.py

@@ -119,3 +119,20 @@ class Settings(BaseSettings):
             strawberry: int = Field(..., frozen=False)
         """
         self.assertCodemod(before, after)
+
+    def test_annotated_field(self) -> None:
+        before = """
+        from pydantic import BaseModel, Field
+        from typing import Annotated
+
+        class Potato(BaseModel):
+            potato: Annotated[List[int], Field(..., min_items=1, max_items=10)]
+        """
+        after = """
+        from pydantic import BaseModel, Field
+        from typing import Annotated
+
+        class Potato(BaseModel):
+            potato: Annotated[List[int], Field(..., min_length=1, max_length=10)]
+        """
+        self.assertCodemod(before, after)