chore(deps): make fsspec and upath optional dependencies (#2534)

* chore(deps): make fsspec and upath optional dependencies

* bump minimal env

* release notes

Author: jhamman

Diff for: docs/release.rst

@@ -18,10 +18,32 @@ Release notes
    See `GH1777 <https://github.com/zarr-developers/zarr-python/issues/1777>`_ for more details on the upcoming
    3.0 release.
 
+.. release_3.0.0-beta:
+
+3.0.0-beta series
+-----------------
+
+.. warning::
+   Zarr-Python 3.0.0-beta is a pre-release of the upcoming 3.0 release. This release is not feature complete or
+   expected to be ready for production applications.
+
+.. note::
+   The complete release notes for 3.0 have not been added to this document yet. See the
+   `3.0.0-beta <https://github.com/zarr-developers/zarr-python/releases/tag/v3.0.0-beta>`_ release on GitHub
+   for a record of changes included in this release.
+
+Dependency Changes
+~~~~~~~~~~~~~~~~~~
+
+* fsspec was moved from a required dependency to an optional one. Users should install
+  fsspec and any relevant implementations (e.g. s3fs) before using the ``RemoteStore``.
+  By :user:`Joe Hamman <jhamman>` :issue:`2391`.
+
+
 .. release_3.0.0-alpha:
 
-3.0.0-alpha
------------
+3.0.0-alpha series
+------------------
 
 .. warning::
    Zarr-Python 3.0.0-alpha is a pre-release of the upcoming 3.0 release. This release is not feature complete or

Diff for: pyproject.toml

@@ -28,8 +28,7 @@ requires-python = ">=3.11"
 dependencies = [
     'numpy>=1.25',
     'numcodecs[crc32c]>=0.14',
-    'fsspec>=2022.10.0',
-    'typing_extensions>=4.6',
+    'typing_extensions>=4.9',
     'donfig>=0.8',
 ]
 
@@ -54,16 +53,16 @@ license = {text = "MIT License"}
 keywords = ["Python", "compressed", "ndimensional-arrays", "zarr"]
 
 [project.optional-dependencies]
+fsspec = [
+    "fsspec>=2023.10.0",
+]
 test = [
     "coverage",
     "pytest",
     "pytest-cov",
-    "msgpack",
     "s3fs",
     "pytest-asyncio",
     "moto[s3]",
-    "flask-cors",
-    "flask",
     "requests",
     "mypy",
     "hypothesis",
@@ -224,7 +223,7 @@ dependencies = [
     'fsspec==2022.10.0',
     's3fs==2022.10.0',
     'universal_pathlib==0.0.22',
-    'typing_extensions==4.6.*',  # 4.5 needed for @deprecated, 4.6 for Buffer
+    'typing_extensions==4.9.*',
     'donfig==0.8.*',
     # test deps
     'hypothesis',

Diff for: tests/test_store/test_core.py

@@ -3,7 +3,6 @@
 
 import pytest
 from _pytest.compat import LEGACY_PATH
-from upath import UPath
 
 from zarr.core.common import AccessModeLiteral
 from zarr.storage._utils import normalize_path
@@ -72,6 +71,7 @@ async def test_make_store_path_invalid() -> None:
 
 
 async def test_make_store_path_fsspec(monkeypatch) -> None:
+    pytest.importorskip("fsspec")
     store_path = await make_store_path("http://foo.com/bar")
     assert isinstance(store_path.store, RemoteStore)
 
@@ -106,13 +106,17 @@ async def test_unsupported() -> None:
         "foo/bar///",
         Path("foo/bar"),
         b"foo/bar",
-        UPath("foo/bar"),
     ],
 )
-def test_normalize_path_valid(path: str | bytes | Path | UPath) -> None:
+def test_normalize_path_valid(path: str | bytes | Path) -> None:
     assert normalize_path(path) == "foo/bar"
 
 
+def test_normalize_path_upath() -> None:
+    upath = pytest.importorskip("upath")
+    assert normalize_path(upath.UPath("foo/bar")) == "foo/bar"
+
+
 def test_normalize_path_none():
     assert normalize_path(None) == ""
 

Diff for: tests/test_store/test_remote.py

@@ -4,10 +4,8 @@
 import os
 from typing import TYPE_CHECKING
 
-import fsspec
 import pytest
 from botocore.session import Session
-from upath import UPath
 
 import zarr.api.asynchronous
 from zarr.core.buffer import Buffer, cpu, default_buffer_prototype
@@ -21,6 +19,7 @@
     import botocore.client
 
 
+fsspec = pytest.importorskip("fsspec")
 s3fs = pytest.importorskip("s3fs")
 requests = pytest.importorskip("requests")
 moto_server = pytest.importorskip("moto.moto_server.threaded_moto_server")
@@ -182,7 +181,8 @@ async def test_remote_store_from_uri(self, store: RemoteStore):
         assert dict(group.attrs) == {"key": "value-3"}
 
     def test_from_upath(self) -> None:
-        path = UPath(
+        upath = pytest.importorskip("upath")
+        path = upath.UPath(
             f"s3://{test_bucket_name}/foo/bar/",
             endpoint_url=endpoint_url,
             anon=False,