Add tests for implementation signatures

fsspec/implementations/tests/conftest.py

@@ -2,6 +2,7 @@
 
 import pytest
 
+import fsspec
 from fsspec.implementations.arrow import ArrowFSWrapper
 from fsspec.implementations.local import LocalFileSystem
 from fsspec.implementations.memory import MemoryFileSystem
@@ -24,15 +25,23 @@ class MultiProtocolFileSystem(LocalFileSystem):
 
 @pytest.fixture(scope="function")
 def fs(request):
-    pyarrow_fs = pytest.importorskip("pyarrow.fs")
-    FileSystem = pyarrow_fs.FileSystem
     if request.param == "arrow":
+        pyarrow_fs = pytest.importorskip("pyarrow.fs")
+        FileSystem = pyarrow_fs.FileSystem
         fs = ArrowFSWrapper(FileSystem.from_uri("file:///")[0])
         return fs
     cls = FILESYSTEMS[request.param]
     return cls()
 
 
+@pytest.fixture(scope="function")
+def fscls(request):
+    try:
+        return fsspec.get_filesystem_class(request.param)
+    except ImportError:
+        pytest.skip(f"filesystem {request.param} not installed")
+
+
 @pytest.fixture(scope="function")
 def temp_file():
     with tempfile.TemporaryDirectory() as temp_dir:

fsspec/implementations/tests/test_common.py

@@ -1,5 +1,6 @@
 import datetime
 import time
+from inspect import signature
 
 import pytest
 
@@ -31,3 +32,116 @@ def test_modified(fs: AbstractFileSystem, temp_file):
         assert modified > created
     finally:
         fs.rm(temp_file)
+
+
+@pytest.mark.xfail
+@pytest.mark.parametrize(
+    "method",
+    [
+        "cat",
+        "cat_file",
+        "cat_ranges",
+        "checksum",
+        "copy",
+        "cp",
+        "cp_file",
+        "created",
+        "delete",
+        "disk_usage",
+        "download",
+        "du",
+        "end_transaction",
+        "exists",
+        "expand_path",
+        "find",
+        "from_json",
+        "get",
+        "get_file",
+        "get_mapper",
+        "glob",
+        "head",
+        "info",
+        "invalidate_cache",
+        "isdir",
+        "isfile",
+        "lexists",
+        "listdir",
+        "ls",
+        "makedir",
+        "makedirs",
+        "mkdir",
+        "mkdirs",
+        "modified",
+        "move",
+        "mv",
+        "open",
+        "pipe",
+        "pipe_file",
+        "put",
+        "put_file",
+        "read_block",
+        "read_bytes",
+        "read_text",
+        "rename",
+        "rm",
+        "rm_file",
+        "rmdir",
+        "sign",
+        "size",
+        "sizes",
+        "start_transaction",
+        "stat",
+        "tail",
+        "to_json",
+        "touch",
+        "ukey",
+        "unstrip_protocol",
+        "upload",
+        "walk",
+        "write_bytes",
+        "write_text",
+    ],
+)
+@pytest.mark.parametrize(
+    "fscls",
+    [
+        "file",
+        "memory",
+        "http",
+        "zip",
+        "tar",
+        "sftp",
+        "ssh",
+        "ftp",
+        "webhdfs",
+        "cached",
+        "blockcache",
+        "filecache",
+        "simplecache",
+        "dask",
+        "dbfs",
+        "github",
+        "git",
+        "smb",
+        "jupyter",
+        "libarchive",
+        "reference",
+        "hdfs",
+    ],
+    indirect=["fscls"],
+)
+def test_signature(fscls, method):
+    abstract_fs = AbstractFileSystem
+    abs_signature = signature(getattr(abstract_fs, method))
+    fs_signature = signature(getattr(fscls, method))
+    # We only compare parameters shown in the abstract class
+    # We allow extra parameters in the subclass
+    for k1, k2 in zip(abs_signature.parameters, fs_signature.parameters):
+        if k1 in ["self", "args", "kwargs"]:
+            continue
+        assert (
+            abs_signature.parameters[k1].kind == fs_signature.parameters[k2].kind
+        ), f"{abs_signature} != {fs_signature}"
+        assert (
+            abs_signature.parameters[k1].default == fs_signature.parameters[k2].default
+        ), f"{abs_signature} != {fs_signature}"