Fix test to handle Windows path separators with pathlib

Use pathlib.Path().as_posix() for cross-platform path comparison.
This handles both Unix (/) and Windows (\) path separators correctly
by normalizing both sides of the comparison.

Also update CLAUDE.md to document preference for pathlib over os.path
for path operations in tests and new code.

Author: jensens

CLAUDE.md

@@ -393,6 +393,10 @@ myext-package_setting = value
 - **Formatting**: Black-compatible (max line length: 120)
 - **Import sorting**: isort with `force_alphabetical_sort = true`, `force_single_line = true`
 - **Type hints**: Use throughout (Python 3.8+ compatible)
+- **Path handling**: Prefer `pathlib.Path` over `os.path` for path operations
+  - Use `pathlib.Path().as_posix()` for cross-platform path comparison
+  - Use `/` operator for path joining: `Path("dir") / "file.txt"`
+  - Only use `os.path.join()` in production code where needed for compatibility
 - **Logging**: Use `logger = logging.getLogger("mxdev")` from [logging.py](src/mxdev/logging.py)
 - **Docstrings**: Document public APIs and complex logic
 

tests/test_config.py

@@ -201,16 +201,30 @@ def test_per_package_target_override():
     # Package without custom target should use default-target
     pkg_default = config.packages["package.with.default.target"]
     assert pkg_default["target"] == "./sources"
-    assert pkg_default["path"] == "./sources/package.with.default.target"
+    # Normalize paths for comparison (handles both Unix / and Windows \)
+    assert (
+        pathlib.Path(pkg_default["path"]).as_posix()
+        == pathlib.Path(pkg_default["target"])
+        .joinpath("package.with.default.target")
+        .as_posix()
+    )
 
     # Package with custom target should use its own target
     pkg_custom = config.packages["package.with.custom.target"]
     assert pkg_custom["target"] == "custom-dir"
-    # BUG: This will fail because config.py uses wrong variable at line 103
-    assert pkg_custom["path"] == "custom-dir/package.with.custom.target"
+    assert (
+        pathlib.Path(pkg_custom["path"]).as_posix()
+        == pathlib.Path(pkg_custom["target"])
+        .joinpath("package.with.custom.target")
+        .as_posix()
+    )
 
     # Package with interpolated target should use the interpolated value
     pkg_interpolated = config.packages["package.with.interpolated.target"]
     assert pkg_interpolated["target"] == "documentation"
-    # BUG: This will also fail for the same reason
-    assert pkg_interpolated["path"] == "documentation/package.with.interpolated.target"
+    assert (
+        pathlib.Path(pkg_interpolated["path"]).as_posix()
+        == pathlib.Path(pkg_interpolated["target"])
+        .joinpath("package.with.interpolated.target")
+        .as_posix()
+    )