Make botocore an optional test dependency (zarr-developers#2768)

* Make botocore an optional test dependency

* Add release notes

Author: dstansby

changes/2768.bugfix.1.rst

@@ -0,0 +1 @@
+Updated the optional test dependencies to include ``botocore`` and ``fsspec``.

changes/2768.bugfix.2.rst

@@ -0,0 +1,2 @@
+Fixed the fsspec tests to skip if ``botocore`` is not installed.
+Previously they would have failed with an import error.

pyproject.toml

@@ -73,10 +73,12 @@ test = [
     "coverage",
     "pytest",
     "pytest-cov",
+    'zarr[remote]',
+    "botocore",
     "s3fs",
+    "moto[s3,server]",
     "pytest-asyncio",
     "pytest-accept",
-    "moto[s3,server]",
     "requests",
     "rich",
     "mypy",

tests/test_store/test_fsspec.py

@@ -5,7 +5,6 @@
 from typing import TYPE_CHECKING
 
 import pytest
-from botocore.session import Session
 from packaging.version import parse as parse_version
 
 import zarr.api.asynchronous
@@ -26,6 +25,7 @@
 requests = pytest.importorskip("requests")
 moto_server = pytest.importorskip("moto.moto_server.threaded_moto_server")
 moto = pytest.importorskip("moto")
+botocore = pytest.importorskip("botocore")
 
 # ### amended from s3fs ### #
 test_bucket_name = "test"
@@ -52,7 +52,7 @@ def s3_base() -> Generator[None, None, None]:
 
 def get_boto3_client() -> botocore.client.BaseClient:
     # NB: we use the sync botocore client for setup
-    session = Session()
+    session = botocore.session.Session()
     return session.create_client("s3", endpoint_url=endpoint_url)