Make methods of abstract base class async

The goal is that the async methods of child classes match the signatures
of the methods of the abstract base class.

The `None` was added in 0e035fb, let's try to remove it.

Author: DimitriPapadopoulos

docs/roadmap.rst

@@ -234,13 +234,13 @@ expose the required methods as async methods.
        async def set_partial_values(self, key_start_values: List[Tuple[str, int, Union[bytes, bytearray, memoryview]]]) -> None:
            ...  # required for writable stores
 
-       async def list(self) -> List[str]:
+       async def list(self) -> AsyncGenerator[str]:
            ...  # required for listable stores
 
-       async def list_prefix(self, prefix: str) -> List[str]:
+       async def list_prefix(self, prefix: str) -> AsyncGenerator[str]:
            ...  # required for listable stores
 
-       async def list_dir(self, prefix: str) -> List[str]:
+       async def list_dir(self, prefix: str) -> AsyncGenerator[str]:
            ...  # required for listable stores
 
        # additional (optional methods)

src/zarr/abc/store.py

@@ -329,17 +329,17 @@ def supports_listing(self) -> bool:
         ...
 
     @abstractmethod
-    def list(self) -> AsyncGenerator[str, None]:
+    async def list(self) -> AsyncGenerator[str]:
         """Retrieve all keys in the store.
 
         Returns
         -------
         AsyncGenerator[str, None]
         """
-        ...
+        yield ""
 
     @abstractmethod
-    def list_prefix(self, prefix: str) -> AsyncGenerator[str, None]:
+    async def list_prefix(self, prefix: str) -> AsyncGenerator[str]:
         """
         Retrieve all keys in the store that begin with a given prefix. Keys are returned relative
         to the root of the store.
@@ -352,10 +352,10 @@ def list_prefix(self, prefix: str) -> AsyncGenerator[str, None]:
         -------
         AsyncGenerator[str, None]
         """
-        ...
+        yield ""
 
     @abstractmethod
-    def list_dir(self, prefix: str) -> AsyncGenerator[str, None]:
+    async def list_dir(self, prefix: str) -> AsyncGenerator[str]:
         """
         Retrieve all keys and prefixes with a given prefix and which do not contain the character
         “/” after the given prefix.
@@ -368,7 +368,7 @@ def list_dir(self, prefix: str) -> AsyncGenerator[str, None]:
         -------
         AsyncGenerator[str, None]
         """
-        ...
+        yield ""
 
     async def delete_dir(self, prefix: str) -> None:
         """

src/zarr/storage/local.py

@@ -217,22 +217,22 @@ async def exists(self, key: str) -> bool:
         path = self.root / key
         return await asyncio.to_thread(path.is_file)
 
-    async def list(self) -> AsyncGenerator[str, None]:
+    async def list(self) -> AsyncGenerator[str]:
         # docstring inherited
         to_strip = self.root.as_posix() + "/"
         for p in list(self.root.rglob("*")):
             if p.is_file():
                 yield p.as_posix().replace(to_strip, "")
 
-    async def list_prefix(self, prefix: str) -> AsyncGenerator[str, None]:
+    async def list_prefix(self, prefix: str) -> AsyncGenerator[str]:
         # docstring inherited
         to_strip = self.root.as_posix() + "/"
         prefix = prefix.rstrip("/")
         for p in (self.root / prefix).rglob("*"):
             if p.is_file():
                 yield p.as_posix().replace(to_strip, "")
 
-    async def list_dir(self, prefix: str) -> AsyncGenerator[str, None]:
+    async def list_dir(self, prefix: str) -> AsyncGenerator[str]:
         # docstring inherited
         base = self.root / prefix
         to_strip = str(base) + "/"

src/zarr/storage/logging.py

@@ -204,19 +204,19 @@ async def set_partial_values(
         with self.log(keys):
             return await self._store.set_partial_values(key_start_values=key_start_values)
 
-    async def list(self) -> AsyncGenerator[str, None]:
+    async def list(self) -> AsyncGenerator[str]:
         # docstring inherited
         with self.log():
             async for key in self._store.list():
                 yield key
 
-    async def list_prefix(self, prefix: str) -> AsyncGenerator[str, None]:
+    async def list_prefix(self, prefix: str) -> AsyncGenerator[str]:
         # docstring inherited
         with self.log(prefix):
             async for key in self._store.list_prefix(prefix=prefix):
                 yield key
 
-    async def list_dir(self, prefix: str) -> AsyncGenerator[str, None]:
+    async def list_dir(self, prefix: str) -> AsyncGenerator[str]:
         # docstring inherited
         with self.log(prefix):
             async for key in self._store.list_dir(prefix=prefix):

src/zarr/storage/memory.py

@@ -147,19 +147,19 @@ async def set_partial_values(self, key_start_values: Iterable[tuple[str, int, by
         # docstring inherited
         raise NotImplementedError
 
-    async def list(self) -> AsyncGenerator[str, None]:
+    async def list(self) -> AsyncGenerator[str]:
         # docstring inherited
         for key in self._store_dict:
             yield key
 
-    async def list_prefix(self, prefix: str) -> AsyncGenerator[str, None]:
+    async def list_prefix(self, prefix: str) -> AsyncGenerator[str]:
         # docstring inherited
         # note: we materialize all dict keys into a list here so we can mutate the dict in-place (e.g. in delete_prefix)
         for key in list(self._store_dict):
             if key.startswith(prefix):
                 yield key
 
-    async def list_dir(self, prefix: str) -> AsyncGenerator[str, None]:
+    async def list_dir(self, prefix: str) -> AsyncGenerator[str]:
         # docstring inherited
         prefix = prefix.rstrip("/")
 

src/zarr/storage/remote.py

@@ -322,13 +322,13 @@ async def set_partial_values(
         # docstring inherited
         raise NotImplementedError
 
-    async def list(self) -> AsyncGenerator[str, None]:
+    async def list(self) -> AsyncGenerator[str]:
         # docstring inherited
         allfiles = await self.fs._find(self.path, detail=False, withdirs=False)
         for onefile in (a.replace(self.path + "/", "") for a in allfiles):
             yield onefile
 
-    async def list_dir(self, prefix: str) -> AsyncGenerator[str, None]:
+    async def list_dir(self, prefix: str) -> AsyncGenerator[str]:
         # docstring inherited
         prefix = f"{self.path}/{prefix.rstrip('/')}"
         try:
@@ -338,7 +338,7 @@ async def list_dir(self, prefix: str) -> AsyncGenerator[str, None]:
         for onefile in (a.replace(prefix + "/", "") for a in allfiles):
             yield onefile.removeprefix(self.path).removeprefix("/")
 
-    async def list_prefix(self, prefix: str) -> AsyncGenerator[str, None]:
+    async def list_prefix(self, prefix: str) -> AsyncGenerator[str]:
         # docstring inherited
         for onefile in await self.fs._find(
             f"{self.path}/{prefix}", detail=False, maxdepth=None, withdirs=False

src/zarr/storage/zip.py

@@ -234,19 +234,19 @@ async def exists(self, key: str) -> bool:
             else:
                 return True
 
-    async def list(self) -> AsyncGenerator[str, None]:
+    async def list(self) -> AsyncGenerator[str]:
         # docstring inherited
         with self._lock:
             for key in self._zf.namelist():
                 yield key
 
-    async def list_prefix(self, prefix: str) -> AsyncGenerator[str, None]:
+    async def list_prefix(self, prefix: str) -> AsyncGenerator[str]:
         # docstring inherited
         async for key in self.list():
             if key.startswith(prefix):
                 yield key
 
-    async def list_dir(self, prefix: str) -> AsyncGenerator[str, None]:
+    async def list_dir(self, prefix: str) -> AsyncGenerator[str]:
         # docstring inherited
         prefix = prefix.rstrip("/")