From ed60b4e2a8b7185ed1c47823efa64ea631e5fac3 Mon Sep 17 00:00:00 2001
From: dangotbanned <125183946+dangotbanned@users.noreply.github.com>
Date: Wed, 3 Jul 2024 10:42:53 +0100
Subject: [PATCH] feat(typing): Ban `typing.Optional` import using `ruff`

The user will see this message ```
altair\utils\data.py:17:5: TID251 `typing.Optional` is banned: Use `Union[T, None]` instead. `typing.Optional` is likely to be confused with `altair.Optional`, which have similar but different semantic meaning. See https://github.com/vega/altair/pull/3449 Found 1 error.
```

Partial fix for https://github.com/vega/altair/pull/3452#discussion_r1663857513
---
 altair/utils/data.py | 3 +--
 pyproject.toml       | 4 ++++
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/altair/utils/data.py b/altair/utils/data.py
index 8ab46a6f7..61923231c 100644
--- a/altair/utils/data.py
+++ b/altair/utils/data.py
@@ -14,7 +14,6 @@
     TypeVar,
     Union,
     Dict,
-    Optional,
     overload,
     runtime_checkable,
 )
@@ -54,7 +53,7 @@ class SupportsGeoInterface(Protocol):
     str, Union[str, Dict[Any, Any], List[Dict[Any, Any]]]
 ]
 ToValuesReturnType: TypeAlias = Dict[str, Union[Dict[Any, Any], List[Dict[Any, Any]]]]
-SampleReturnType = Optional[Union[pd.DataFrame, Dict[str, Sequence], "pa.lib.Table"]]
+SampleReturnType = Union[pd.DataFrame, Dict[str, Sequence], "pa.lib.Table", None]
 
 
 def is_data_type(obj: Any) -> TypeIs[DataType]:
diff --git a/pyproject.toml b/pyproject.toml
index 931c34581..e6affe2ac 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -319,6 +319,10 @@ unfixable= [
 [tool.ruff.lint.mccabe]
 max-complexity = 18
 
+[tool.ruff.lint.flake8-tidy-imports.banned-api]
+# https://docs.astral.sh/ruff/settings/#lint_flake8-tidy-imports_banned-api
+"typing.Optional".msg = "Use `Union[T, None]` instead.\n`typing.Optional` is likely to be confused with `altair.Optional`, which have similar but different semantic meaning.\nSee https://github.com/vega/altair/pull/3449"
+
 [tool.ruff.format]
 quote-style = "double"
 indent-style = "space"