fix windows filepath parsing bug, and add tests for parse_store_url

Author: d-v-b

src/zarr/storage/_utils.py

@@ -1,7 +1,8 @@
 from __future__ import annotations
 
 import re
-from pathlib import Path
+import sys
+from pathlib import Path, PureWindowsPath
 from typing import TYPE_CHECKING, NamedTuple, TypeVar
 from urllib.parse import urlparse
 
@@ -65,6 +66,12 @@ def parse_store_url(url: str) -> ParsedStoreUrl:
     >>> parse_store_url("/local/path")
     ParsedStoreUrl(scheme='', name=None, path='/local/path', raw='/local/path')
     """
+    # On Windows, bare paths like "C:\foo" or "C:/foo" cause urlparse to
+    # misinterpret the drive letter as a URL scheme.  Detect this early and
+    # return a local-path result without going through urlparse.
+    if sys.platform == "win32" and PureWindowsPath(url).drive:
+        return ParsedStoreUrl(scheme="", name=None, path=url, raw=url)
+
     parsed = urlparse(url)
 
     # netloc is the "host" part (store name for memory://, bucket for s3://, etc.)

tests/test_store/test_utils.py

@@ -0,0 +1,97 @@
+from __future__ import annotations
+
+import sys
+from unittest.mock import patch
+
+import pytest
+
+from zarr.storage._utils import ParsedStoreUrl, parse_store_url
+
+
+class TestParseStoreUrl:
+    """Tests for parse_store_url."""
+
+    def test_memory_url(self) -> None:
+        result = parse_store_url("memory://mystore")
+        assert result == ParsedStoreUrl(
+            scheme="memory", name="mystore", path="", raw="memory://mystore"
+        )
+
+    def test_memory_url_with_path(self) -> None:
+        result = parse_store_url("memory://mystore/path/to/data")
+        assert result == ParsedStoreUrl(
+            scheme="memory",
+            name="mystore",
+            path="path/to/data",
+            raw="memory://mystore/path/to/data",
+        )
+
+    def test_memory_url_no_name(self) -> None:
+        result = parse_store_url("memory://")
+        assert result.scheme == "memory"
+        assert result.name is None
+
+    def test_s3_url(self) -> None:
+        result = parse_store_url("s3://bucket/key")
+        assert result == ParsedStoreUrl(
+            scheme="s3", name="bucket", path="key", raw="s3://bucket/key"
+        )
+
+    def test_file_url(self) -> None:
+        result = parse_store_url("file:///tmp/test")
+        assert result.scheme == "file"
+
+    def test_local_absolute_path(self) -> None:
+        result = parse_store_url("/local/path")
+        assert result == ParsedStoreUrl(scheme="", name=None, path="/local/path", raw="/local/path")
+
+    def test_local_relative_path(self) -> None:
+        result = parse_store_url("relative/path")
+        assert result == ParsedStoreUrl(
+            scheme="", name=None, path="relative/path", raw="relative/path"
+        )
+
+    @pytest.mark.parametrize(
+        "url",
+        [
+            "C:\\Users\\foo",
+            "C:/Users/foo",
+            "D:/data/zarr",
+            "c:/test",
+        ],
+    )
+    def test_windows_drive_letter(self, url: str) -> None:
+        """On Windows, bare drive-letter paths must be treated as local paths."""
+        with patch.object(sys, "platform", "win32"):
+            result = parse_store_url(url)
+        assert result.scheme == ""
+        assert result.name is None
+        assert result.path == url
+        assert result.raw == url
+
+    @pytest.mark.parametrize(
+        "url",
+        [
+            "file:///C:/Users/foo",
+            "file://C:/Users/foo",
+        ],
+    )
+    def test_file_url_with_drive_letter_on_windows(self, url: str) -> None:
+        """file:// URLs with drive letters are not treated as bare paths."""
+        with patch.object(sys, "platform", "win32"):
+            result = parse_store_url(url)
+        assert result.scheme == "file"
+
+    @pytest.mark.parametrize(
+        "url",
+        [
+            "C:\\Users\\foo",
+            "C:/Users/foo",
+        ],
+    )
+    def test_drive_letter_not_special_on_non_windows(self, url: str) -> None:
+        """On non-Windows platforms, drive-letter paths go through urlparse."""
+        with patch.object(sys, "platform", "linux"):
+            result = parse_store_url(url)
+        # urlparse interprets the drive letter as a scheme
+        assert result.scheme == "c"