Don't add default None when default is ...

Author: Kludex

bump_pydantic/codemods/add_default_none.py

@@ -81,18 +81,22 @@ def leave_AnnAssign(self, original_node: cst.AnnAssign, updated_node: cst.AnnAss
         if self.inside_base_model and self.should_add_none:
             if updated_node.value is None:
                 updated_node = updated_node.with_changes(value=cst.Name("None"))
-            # TODO: Should accept `pydantic.Field` as well.
             elif m.matches(updated_node.value, m.Call(func=m.Name("Field"))):
                 assert isinstance(updated_node.value, cst.Call)
-                if updated_node.value.args:
-                    arg = updated_node.value.args[0]
-                    if (arg.keyword is None or arg.keyword.value == "default") and m.matches(arg.value, m.Ellipsis()):
+                args = updated_node.value.args
+                if args:
+                    # NOTE: It has a "default" value as positional argument. Nothing to do.
+                    if args[0].keyword is None:
+                        ...
+                    # NOTE: It has a "default" or "default_factory" keyword argument. Nothing to do.
+                    elif any(arg.keyword and arg.keyword.value in ("default", "default_factory") for arg in args):
+                        ...
+                    else:
                         updated_node = updated_node.with_changes(
-                            value=updated_node.value.with_changes(
-                                args=[arg.with_changes(value=cst.Name("None")), *updated_node.value.args[1:]]
-                            )
+                            value=updated_node.value.with_changes(args=[cst.Arg(value=cst.Name("None")), *args])
                         )
-                # This is the case where `Field` is called without any arguments e.g. `Field()`.
+
+                # NOTE: This is the case where `Field` is called without any arguments e.g. `Field()`.
                 else:
                     updated_node = updated_node.with_changes(
                         value=updated_node.value.with_changes(args=[cst.Arg(value=cst.Name("None"))])  # type: ignore

tests/integration/cases/add_none.py

@@ -22,6 +22,12 @@
                 "    g: Optional[int] = Field()",
                 "    h: Optional[int] = Field(...)",
                 "    i: Optional[int] = Field(default_factory=lambda: None)",
+                "    j: Optional[int] = ...",
+                "    k: Optional[int] = None",
+                "    l: Optional[int] = Field(lt=10, default=None)",
+                "    m: Optional[int] = Field(lt=10)",
+                "    n: Optional[int] = Field(default=...)",
+                "    o: Optional[int] = Field(default=None)",
             ],
         ),
         expected=File(
@@ -38,10 +44,16 @@
                 "    c: Union[int, None] = None",
                 "    d: Any = None",
                 "    e: Dict[str, str]",
-                "    f: Optional[int] = Field(None, lt=10)",
+                "    f: Optional[int] = Field(..., lt=10)",
                 "    g: Optional[int] = Field(None)",
-                "    h: Optional[int] = Field(None)",
+                "    h: Optional[int] = Field(...)",
                 "    i: Optional[int] = Field(default_factory=lambda: None)",
+                "    j: Optional[int] = ...",
+                "    k: Optional[int] = None",
+                "    l: Optional[int] = Field(lt=10, default=None)",
+                "    m: Optional[int] = Field(None, lt=10)",
+                "    n: Optional[int] = Field(default=...)",
+                "    o: Optional[int] = Field(default=None)",
             ],
         ),
     )