Add missing open_async() to DirFileSystem (fixes #1698)

Author: orenl

fsspec/implementations/dirfs.py

@@ -370,3 +370,15 @@ def open(
             *args,
             **kwargs,
         )
+
+    async def open_async(
+        self,
+        path,
+        *args,
+        **kwargs,
+    ):
+        return await self.fs.open_async(
+            self._join(path),
+            *args,
+            **kwargs,
+        )

fsspec/implementations/tests/test_dirfs.py

@@ -589,6 +589,13 @@ def test_sign(mocker, dirfs):
     dirfs.fs.sign.assert_called_once_with(f"{PATH}/file", *ARGS, **KWARGS)
 
 
+@pytest.mark.asyncio
+async def test_open_async(mocker, adirfs):
+    adirfs.fs.open_async = mocker.AsyncMock()
+    assert await adirfs.open_async("file", *ARGS, **KWARGS) == adirfs.fs.open_async.return_value
+    adirfs.fs.open_async.assert_called_once_with(f"{PATH}/file", *ARGS, **KWARGS)
+
+
 def test_open(mocker, dirfs):
     dirfs.fs.open = mocker.Mock()
     assert dirfs.open("file", *ARGS, **KWARGS) == dirfs.fs.open.return_value