From fe0ae88201cc699b32ee1e9c07b602d9d7a8d439 Mon Sep 17 00:00:00 2001
From: dangotbanned <125183946+dangotbanned@users.noreply.github.com>
Date: Sun, 10 Nov 2024 20:56:22 +0000
Subject: [PATCH] fix(DRAFT): Treat `polars` as exception, invalidate cache

Possibly fix https://github.com/vega/altair/actions/runs/11768349827/job/32778071725?pr=3631
---
 altair/datasets/_readers.py | 13 ++++++++-----
 tests/test_datasets.py      |  1 +
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/altair/datasets/_readers.py b/altair/datasets/_readers.py
index f58fcd56d..eea9f18db 100644
--- a/altair/datasets/_readers.py
+++ b/altair/datasets/_readers.py
@@ -99,8 +99,8 @@ def scan_fn(self, source: StrPath, /) -> Callable[..., IntoFrameT]:
         return self._scan_fn[suffix]
 
     def _response_hook(self, f):
-        # HACK: pyarrow wants the file obj
-        return f.read()
+        # HACK: `pyarrow` + `pandas` wants the file obj
+        return f
 
     def dataset(
         self,
@@ -273,6 +273,9 @@ def __init__(self, name: _Polars, /) -> None:
         }
         self._scan_fn = {".parquet": pl.scan_parquet}
 
+    def _response_hook(self, f):
+        return f.read()
+
 
 class _PolarsPyArrowReader(_Reader["pl.DataFrame", "pl.LazyFrame"]):
     def __init__(self, name: Literal["polars[pyarrow]"], /) -> None:
@@ -289,6 +292,9 @@ def __init__(self, name: Literal["polars[pyarrow]"], /) -> None:
         }
         self._scan_fn = {".parquet": pl.scan_parquet}
 
+    def _response_hook(self, f):
+        return f.read()
+
 
 class _PyArrowReader(_Reader["pa.Table", "pa.Table"]):
     """
@@ -333,9 +339,6 @@ def __init__(self, name: _PyArrow, /) -> None:
         }
         self._scan_fn = {".parquet": pa_read_parquet}
 
-    def _response_hook(self, f):
-        return f
-
 
 def _filter_reduce(predicates: tuple[Any, ...], constraints: Metadata, /) -> nw.Expr:
     """
diff --git a/tests/test_datasets.py b/tests/test_datasets.py
index a15fb9411..c37bc0046 100644
--- a/tests/test_datasets.py
+++ b/tests/test_datasets.py
@@ -39,6 +39,7 @@ def test_loader_url(backend: _Backend) -> None:
 @backends
 def test_loader_call(backend: _Backend) -> None:
     data = Loader.with_backend(backend)
+    data.cache_dir = ""
     frame = data("stocks", ".csv")
     assert is_into_dataframe(frame)
     nw_frame = nw.from_native(frame)