Suppress xet install WARN if HF_HUB_DISABLE_XET (#3206)

* Suppress xet install WARN if HF_HUB_DISABLE_XET

* PR feedback, removing is_xet_disabled()

* Created contants.HF_HUB_DISABLE_XET and using it

* Fixed unit test

Author: rajatarya

src/huggingface_hub/constants.py

@@ -291,3 +291,4 @@ def _as_int(value: Optional[str]) -> Optional[int]:
 
 default_xet_cache_path = os.path.join(HF_HOME, "xet")
 HF_XET_CACHE = os.getenv("HF_XET_CACHE", default_xet_cache_path)
+HF_HUB_DISABLE_XET: bool = _is_true(os.environ.get("HF_HUB_DISABLE_XET"))

src/huggingface_hub/file_download.py

@@ -1718,7 +1718,7 @@ def _download_to_tmp_and_move(
                 displayed_filename=filename,
             )
         else:
-            if xet_file_data is not None:
+            if xet_file_data is not None and not constants.HF_HUB_DISABLE_XET:
                 logger.warning(
                     "Xet Storage is enabled for this repo, but the 'hf_xet' package is not installed. "
                     "Falling back to regular HTTP download. "

src/huggingface_hub/utils/_runtime.py

@@ -155,7 +155,7 @@ def get_hf_transfer_version() -> str:
 # xet
 def is_xet_available() -> bool:
     # since hf_xet is automatically used if available, allow explicit disabling via environment variable
-    if constants._is_true(os.environ.get("HF_HUB_DISABLE_XET")):  # type: ignore
+    if constants.HF_HUB_DISABLE_XET:
         return False
 
     return is_package_available("hf_xet")

tests/test_xet_utils.py

@@ -288,5 +288,6 @@ def test_env_var_hf_hub_disable_xet() -> None:
     from huggingface_hub.utils._runtime import is_xet_available
 
     monkeypatch = MonkeyPatch()
-    monkeypatch.setenv("HF_HUB_DISABLE_XET", "1")
+    monkeypatch.setattr("huggingface_hub.constants.HF_HUB_DISABLE_XET", True)
+
     assert not is_xet_available()