Return info for archive FSs root (#996)

* Return info for archive FSs

* only if archive is not empty

* update test py versions

Author: martindurant

.github/workflows/main.yaml

@@ -13,7 +13,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        TOXENV: [py37, py38, py39, s3fs, gcsfs]
+        TOXENV: [py38, py39, py310, s3fs, gcsfs]
 
     env:
       TOXENV: ${{ matrix.TOXENV }}
@@ -42,7 +42,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        TOXENV: [py38]
+        TOXENV: [py39]
 
     env:
       TOXENV: ${{ matrix.TOXENV }}

fsspec/archive.py

@@ -34,6 +34,8 @@ def _all_dirnames(self, paths):
     def info(self, path, **kwargs):
         self._get_dirs()
         path = self._strip_protocol(path)
+        if path in {"", "/"} and self.dir_cache:
+            return {"name": "/", "type": "directory", "size": 0}
         if path in self.dir_cache:
             return self.dir_cache[path]
         elif path + "/" in self.dir_cache:

fsspec/implementations/tests/test_zip.py

@@ -39,3 +39,10 @@ def test_not_cached():
         fs = fsspec.filesystem("zip", fo=z)
         fs2 = fsspec.filesystem("zip", fo=z)
         assert fs is not fs2
+
+
+def test_root_info():
+    with tempzip(archive_data) as z:
+        fs = fsspec.filesystem("zip", fo=z)
+        assert fs.info("/") == {"name": "/", "type": "directory", "size": 0}
+        assert fs.info("") == {"name": "/", "type": "directory", "size": 0}

tox.ini

@@ -1,6 +1,6 @@
 # content of: tox.ini , put in same dir as setup.py
 [tox]
-envlist = {py37,py38,py39}
+envlist = {py38,py39,py310}
 
 [core]
 conda_channels=
@@ -41,7 +41,6 @@ conda_deps=
 deps=
     hadoop-test-cluster==0.1.0
     smbprotocol
-    py37: importlib_metadata
 
 [testenv]
 description=Run test suite against target versions.