chore(ruff): standardize optional union ordering

marimo/_ast/pytest.py

@@ -40,8 +40,8 @@ def _pytest_scaffold(stub: Any) -> Any:
 def build_stub_fn(
     func_body: ast.FunctionDef | ast.AsyncFunctionDef,
     file: str = "",
-    basis: None | Callable[..., Any] = None,
-    allowed: None | list[str] = None,
+    basis: Callable[..., Any] | None = None,
+    allowed: list[str] | None = None,
 ) -> Callable[..., Any]:
     # Avoid declaring the function in the global scope, since it may cause
     # issues with meta-analysis tools like cxfreeze (see #3828).

marimo/_lint/diagnostic.py

@@ -29,7 +29,7 @@ class Diagnostic:
     message: str
     line: int | list[int]
     column: int | list[int]
-    cell_id: None | list[CellId_t] = None
+    cell_id: list[CellId_t] | None = None
     code: str | None = None
     name: str | None = None
     severity: Severity | None = None

marimo/_messaging/notification.py

@@ -112,7 +112,7 @@ class CellNotification(Notification, tag="cell-op"):
     # Tri-state partial update: UNSET (omitted on the wire) leaves the cell's
     # serialization hint unchanged; None explicitly clears it (cell is no
     # longer a top-level definition); a string sets it.
-    serialization: str | None | msgspec.UnsetType = msgspec.UNSET
+    serialization: str | msgspec.UnsetType | None = msgspec.UNSET
     timestamp: float = msgspec.field(default_factory=lambda: time.time())
 
     def __post_init__(self) -> None:

marimo/_output/formatters/structures.py

@@ -94,7 +94,7 @@ def _escape_fallback(s: str) -> str:
 
 def _leaf_formatter(
     value: object,
-) -> bool | None | str | int:
+) -> bool | str | int | None:
     formatter = formatting.get_formatter(value)
 
     # Because we don't flatten subclasses of structures, we need to avoid

marimo/_runtime/dataflow/graph.py

@@ -374,7 +374,7 @@ def get_transitive_references(
             return processed | refs
         return processed - refs
 
-    def copy(self, filename: None | str = None) -> DirectedGraph:
+    def copy(self, filename: str | None = None) -> DirectedGraph:
         """Return a deep copy of the graph by recompiling all cells.
 
         This is mainly useful in the case where recompilation must be done

marimo/_runtime/packages/import_error_extractors.py

@@ -12,7 +12,7 @@ def extract_missing_module_from_cause_chain(
     This handles cases where a `ModuleNotFoundError` was raised and then wrapped,
     e.g., via `raise ImportError("helpful message") from err`
     """
-    current: None | BaseException = error
+    current: BaseException | None = error
     while current is not None:
         if (
             isinstance(current, ModuleNotFoundError)

marimo/_save/loaders/lazy.py

@@ -615,8 +615,8 @@ def __init__(
         self,
         name: str,
         store: Store | None = None,
-        signer: CacheSigner | None | _Unset = _SIGNER_UNSET,
-        trusted_signers: Iterable[str] | None | _Unset = _TRUSTED_UNSET,
+        signer: CacheSigner | _Unset | None = _SIGNER_UNSET,
+        trusted_signers: Iterable[str] | _Unset | None = _TRUSTED_UNSET,
         verification: str | _Unset = _VERIFICATION_UNSET,
     ) -> None:
         """Create a LazyLoader.
@@ -847,7 +847,7 @@ def signer(self) -> CacheSigner | None:
         return self._signer
 
     @signer.setter
-    def signer(self, value: CacheSigner | None | _Unset) -> None:
+    def signer(self, value: CacheSigner | _Unset | None) -> None:
         # Validate up front (mirrors __init__) so a bad reconfigure fails here
         # rather than as an AttributeError mid-save.
         if not isinstance(value, (_Unset, CacheSigner)) and value is not None:

marimo/_schemas/export.py

@@ -36,7 +36,7 @@ class ExportAsHTMLRequest(msgspec.Struct, rename="camel"):
     files: list[str]
     include_code: bool
     asset_url: str | None = None
-    layout: LayoutConfig | None | msgspec.UnsetType = msgspec.UNSET
+    layout: LayoutConfig | msgspec.UnsetType | None = msgspec.UNSET
 
 
 def to_html_export_options(

marimo/_server/ai/mcp/types.py

@@ -8,8 +8,8 @@
     | int
     | float
     | bool
-    | None
     | list["MCPToolValue"]
     | dict[str, "MCPToolValue"]
+    | None
 )
 MCPToolArgs: TypeAlias = dict[str, MCPToolValue] | None

marimo/_utils/env.py

@@ -16,7 +16,7 @@ def is_env_true(key: str, default: bool = False) -> bool:
     return value.strip().lower() in ("true", "1")
 
 
-def env_to_value(key: str) -> tuple[str | None | list[str] | bool] | None:
+def env_to_value(key: str) -> tuple[str | list[str] | bool | None] | None:
     """Return a typed value from environment variables."""
     if key in os.environ:
         value = os.environ[key]

marimo/_utils/lists.py

@@ -14,7 +14,7 @@ def first(iterable: Iterable[T] | T) -> T:
         return iterable
 
 
-def as_list(value: T | None | list[T]) -> list[T]:
+def as_list(value: T | list[T] | None) -> list[T]:
     if value is None:
         return []
     return value if isinstance(value, list) else [value]  # type: ignore[no-any-return]

pyproject.toml

@@ -389,7 +389,6 @@ ignore = [
     "FURB189", # Subclassing built-in collections
     "FURB152", # Replace literal with a math constant
     "FURB110", # Replace ternary with an `or` expression
-    "RUF036", # `None` is not last in a union
     "FURB113", # Repeated `append` calls
     "NPY002", # Legacy NumPy random API
     "RUF100", # Unused `noqa` directive