fix: resolve infinite loop in _find_config on Windows systems (#4970)

* fix: resolve Windows path handling in _find_config

* Replace Path.match("/") with Path.anchor comparison
* Fix infinite loop in _studio.py path traversal

* test: Add tests for the new root path exploration

* Fix formatting style

* Fixed line to long

* Fix docstyle by running black manually

* Fix testcase with \\ when running on non-windows machines

* Fix formatting style

* cleanup unused import

Author: Julfried

src/sagemaker/_studio.py

@@ -65,7 +65,10 @@ def _find_config(working_dir=None):
         wd = Path(working_dir) if working_dir else Path.cwd()
 
         path = None
-        while path is None and not wd.match("/"):
+
+        # Get the root of the current working directory for both Windows and Unix-like systems
+        root = Path(wd.anchor)
+        while path is None and wd != root:
             candidate = wd / STUDIO_PROJECT_CONFIG
             if Path.exists(candidate):
                 path = candidate

tests/unit/sagemaker/test_studio.py

@@ -12,7 +12,8 @@
 # language governing permissions and limitations under the License.
 # language governing permissions and limitations under the License.
 from __future__ import absolute_import
-
+import os
+from pathlib import Path
 from sagemaker._studio import (
     _append_project_tags,
     _find_config,
@@ -21,6 +22,66 @@
 )
 
 
+def test_find_config_cross_platform(tmpdir):
+    """Test _find_config works correctly across different platforms."""
+    # Create a completely separate directory for isolated tests
+    import tempfile
+
+    with tempfile.TemporaryDirectory() as isolated_root:
+        # Setup test directory structure for positive tests
+        config = tmpdir.join(".sagemaker-code-config")
+        config.write('{"sagemakerProjectId": "proj-1234"}')
+
+        # Test 1: Direct parent directory
+        working_dir = tmpdir.mkdir("sub")
+        found_path = _find_config(working_dir)
+        assert found_path == config
+
+        # Test 2: Deeply nested directories
+        nested_dir = tmpdir.mkdir("deep").mkdir("nested").mkdir("path")
+        found_path = _find_config(nested_dir)
+        assert found_path == config
+
+        # Test 3: Start from root directory
+        import os
+
+        root_dir = os.path.abspath(os.sep)
+        found_path = _find_config(root_dir)
+        assert found_path is None
+
+        # Test 4: No config file in path - using truly isolated directory
+        isolated_path = Path(isolated_root) / "nested" / "path"
+        isolated_path.mkdir(parents=True)
+        found_path = _find_config(isolated_path)
+        assert found_path is None
+
+
+def test_find_config_path_separators(tmpdir):
+    """Test _find_config handles different path separator styles.
+
+    Tests:
+    1. Forward slashes
+    2. Backslashes
+    3. Mixed separators
+    """
+    # Setup
+    config = tmpdir.join(".sagemaker-code-config")
+    config.write('{"sagemakerProjectId": "proj-1234"}')
+    base_path = str(tmpdir)
+
+    # Always include the OS native path and forward slashes (which are equivalent on all OS)
+    paths = [os.path.join(base_path, "dir1", "dir2"), "/".join([base_path, "dir1", "dir2"])]
+
+    # Only on Windows add the backslashes and mixed separator test cases.
+    if os.name == "nt":
+        paths.extend(["\\".join([base_path, "dir1", "dir2"]), base_path + "/dir1\\dir2"])
+
+    for path in paths:
+        os.makedirs(path, exist_ok=True)
+        found_path = _find_config(path)
+        assert found_path == config
+
+
 def test_find_config(tmpdir):
     path = tmpdir.join(".sagemaker-code-config")
     path.write('{"sagemakerProjectId": "proj-1234"}')