fix(remotestore): raise error if path includes scheme

docs/guide/storage.rst

@@ -72,7 +72,7 @@ that implements the `AbstractFileSystem` API,
 .. code-block:: python
 
    >>> import zarr
-   >>> store = zarr.storage.RemoteStore("gs://foo/bar", mode="r")
+   >>> store = zarr.storage.RemoteStore.from_url("gs://foo/bar", mode="r")
    >>> zarr.open(store=store)
    <Array <RemoteStore(GCSFileSystem, foo/bar)> shape=(10, 20) dtype=float32>
 

src/zarr/abc/store.py

@@ -168,7 +168,7 @@ def with_mode(self, mode: AccessModeLiteral) -> Self:
 
         Returns
         -------
-        store:
+        store
             A new store of the same type with the new mode.
 
         Examples

src/zarr/storage/remote.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import warnings
 from typing import TYPE_CHECKING, Any, Self
 
 from zarr.abc.store import ByteRangeRequest, Store
@@ -32,7 +33,8 @@ class RemoteStore(Store):
     mode : AccessModeLiteral
         The access mode to use.
     path : str
-        The root path of the store.
+        The root path of the store. This should be a relative path and must not include the
+        filesystem scheme.
     allowed_exceptions : tuple[type[Exception], ...]
         When fetching data, these cases will be deemed to correspond to missing keys.
 
@@ -44,6 +46,23 @@ class RemoteStore(Store):
     supports_deletes
     supports_partial_writes
     supports_listing
+
+    Raises
+    ------
+    TypeError
+        If the Filesystem does not support async operations.
+    ValueError
+        If the path argument includes a scheme.
+
+    Warns
+    -----
+    UserWarning
+        If the file system (fs) was not created with `asynchronous=True`.
+
+    See Also
+    --------
+    RemoteStore.from_upath
+    RemoteStore.from_url
     """
 
     # based on FSSpec
@@ -69,6 +88,15 @@ def __init__(
 
         if not self.fs.async_impl:
             raise TypeError("Filesystem needs to support async operations.")
+        if not self.fs.asynchronous:
+            warnings.warn(
+                f"fs ({fs}) was not created with `asynchronous=True`, this may lead to surprising behavior",
+                stacklevel=2,
+            )
+        if "://" in path and not path.startswith("http"):
+            # `not path.startswith("http")` is a special case for the http filesystem (¯\_(ツ)_/¯)
+            scheme, _ = path.split("://", maxsplit=1)
+            raise ValueError(f"path argument to RemoteStore must not include scheme ({scheme}://)")
 
     @classmethod
     def from_upath(
@@ -134,7 +162,17 @@ def from_url(
             # before fsspec==2024.3.1
             from fsspec.core import url_to_fs
 
-        fs, path = url_to_fs(url, **storage_options)
+        opts = storage_options or {}
+        opts = {"asynchronous": True, **opts}
+
+        fs, path = url_to_fs(url, **opts)
+
+        # fsspec is not consistent about removing the scheme from the path, so check and strip it here
+        # https://github.com/fsspec/filesystem_spec/issues/1722
+        if "://" in path and not path.startswith("http"):
+            # `not path.startswith("http")` is a special case for the http filesystem (¯\_(ツ)_/¯)
+            path = fs._strip_protocol(path)
+
         return cls(fs=fs, path=path, mode=mode, allowed_exceptions=allowed_exceptions)
 
     async def clear(self) -> None:

tests/test_store/test_core.py

@@ -71,10 +71,7 @@ async def test_make_store_path_invalid() -> None:
 
 
 async def test_make_store_path_fsspec(monkeypatch) -> None:
-    import fsspec.implementations.memory
-
-    monkeypatch.setattr(fsspec.implementations.memory.MemoryFileSystem, "async_impl", True)
-    store_path = await make_store_path("memory://")
+    store_path = await make_store_path("http://foo.com/bar")
     assert isinstance(store_path.store, RemoteStore)
 
 

tests/test_store/test_remote.py

@@ -86,10 +86,12 @@ def s3(s3_base: None) -> Generator[s3fs.S3FileSystem, None, None]:
 
 async def test_basic() -> None:
     store = RemoteStore.from_url(
-        f"s3://{test_bucket_name}",
+        f"s3://{test_bucket_name}/foo/spam/",
         mode="w",
         storage_options={"endpoint_url": endpoint_url, "anon": False},
     )
+    assert store.fs.asynchronous
+    assert store.path == f"{test_bucket_name}/foo/spam"
     assert await _collect_aiterator(store.list()) == ()
     assert not await store.exists("foo")
     data = b"hello"
@@ -109,7 +111,7 @@ class TestRemoteStoreS3(StoreTests[RemoteStore, cpu.Buffer]):
     @pytest.fixture
     def store_kwargs(self, request) -> dict[str, str | bool]:
         fs, path = fsspec.url_to_fs(
-            f"s3://{test_bucket_name}", endpoint_url=endpoint_url, anon=False
+            f"s3://{test_bucket_name}", endpoint_url=endpoint_url, anon=False, asynchronous=True
         )
         return {"fs": fs, "path": path, "mode": "r+"}
 
@@ -143,9 +145,7 @@ def test_store_supports_partial_writes(self, store: RemoteStore) -> None:
     def test_store_supports_listing(self, store: RemoteStore) -> None:
         assert store.supports_listing
 
-    async def test_remote_store_from_uri(
-        self, store: RemoteStore, store_kwargs: dict[str, str | bool]
-    ):
+    async def test_remote_store_from_uri(self, store: RemoteStore):
         storage_options = {
             "endpoint_url": endpoint_url,
             "anon": False,
@@ -183,9 +183,32 @@ async def test_remote_store_from_uri(
         assert dict(group.attrs) == {"key": "value-3"}
 
     def test_from_upath(self) -> None:
-        path = UPath(f"s3://{test_bucket_name}", endpoint_url=endpoint_url, anon=False)
+        path = UPath(
+            f"s3://{test_bucket_name}/foo/bar/",
+            endpoint_url=endpoint_url,
+            anon=False,
+            asynchronous=True,
+        )
         result = RemoteStore.from_upath(path)
         assert result.fs.endpoint_url == endpoint_url
+        assert result.fs.asynchronous
+        assert result.path == f"{test_bucket_name}/foo/bar"
+
+    def test_init_raises_if_path_has_scheme(self, store_kwargs) -> None:
+        # regression test for https://github.com/zarr-developers/zarr-python/issues/2342
+        store_kwargs["path"] = "s3://" + store_kwargs["path"]
+        with pytest.raises(
+            ValueError, match="path argument to RemoteStore must not include scheme .*"
+        ):
+            self.store_cls(**store_kwargs)
+
+    def test_init_warns_if_fs_asynchronous_is_false(self) -> None:
+        fs, path = fsspec.url_to_fs(
+            f"s3://{test_bucket_name}", endpoint_url=endpoint_url, anon=False, asynchronous=False
+        )
+        store_kwargs = {"fs": fs, "path": path, "mode": "r+"}
+        with pytest.warns(UserWarning, match=r".* was not created with `asynchronous=True`.*"):
+            self.store_cls(**store_kwargs)
 
     async def test_empty_nonexistent_path(self, store_kwargs) -> None:
         # regression test for https://github.com/zarr-developers/zarr-python/pull/2343