test: Add tests for the new root path exploration

tests/unit/sagemaker/test_studio.py

@@ -12,14 +12,71 @@
 # 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,
     _load_config,
     _parse_tags,
 )
 
+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)
+
+    # Test different path separator styles
+    paths = [
+        os.path.join(base_path, "dir1", "dir2"),  # OS native
+        "/".join([base_path, "dir1", "dir2"]),    # Forward slashes
+        "\\".join([base_path, "dir1", "dir2"]),   # Backslashes
+        base_path + "/dir1\\dir2"                 # Mixed
+    ]
+
+    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")