Fix for slower exists() and info() calls (fsspec#705)

Co-authored-by: Ankita Luthra <[email protected]>

Author: Mahalaxmibejugam

gcsfs/core.py

@@ -796,7 +796,7 @@ async def _sequential_list_objects_helper(
         items.extend(page.get("items", []))
         next_page_token = page.get("nextPageToken", None)
 
-        while len(items) < max_results and next_page_token is not None:
+        while len(items) + len(prefixes) < max_results and next_page_token is not None:
             num_items = min(items_per_call, max_results - len(items), 1000)
             page = await self._call(
                 "GET",

gcsfs/tests/test_core.py

@@ -224,6 +224,35 @@ def test_info(gcs):
     assert gcs.info(a)["mtime"] == gcs.modified(a)
 
 
+def test_info_on_directory_with_only_subdirectories(gcs):
+    """Test info() on a path that contains no direct files but has subdirectories."""
+    # Setup: create a file inside a nested directory
+    path = f"{TEST_BUCKET}/dir_with_only_subdirs/subdir1/file.txt"
+    gcs.touch(path)
+    path = f"{TEST_BUCKET}/dir_with_only_subdirs/subdir2/file.txt"
+    gcs.touch(path)
+    path = f"{TEST_BUCKET}/dir_with_only_subdirs/subdir3/file.txt"
+    gcs.touch(path)
+    path = f"{TEST_BUCKET}/dir_with_only_subdirs/subdir4/file.txt"
+    gcs.touch(path)
+
+    # The path to test with info()
+    dir_path = f"{TEST_BUCKET}/dir_with_only_subdirs"
+
+    # Mock the _call method to count invocations
+    with mock.patch.object(gcs, "_call", wraps=gcs._call) as mock_call:
+        # Get info for the directory
+        info = gcs.info(dir_path)
+
+        # Assertions
+        assert info["type"] == "directory"
+        assert info["name"] == dir_path
+        # one call is for exact file check and one call for directory
+        assert (
+            mock_call.call_count == 2
+        ), "info() should only make two calls to GCS for a directory."
+
+
 def test_ls2(gcs):
     assert TEST_BUCKET + "/" in gcs.ls("")
     with pytest.raises((OSError, IOError)):