Refactor SDF handling logic for non-existing string paths

src/rod/sdf/sdf.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import dataclasses
-import os
 import pathlib
 
 import mashumaro
@@ -60,34 +59,28 @@ def load(sdf: pathlib.Path | str, is_urdf: bool | None = None) -> Sdf:
             The parsed SDF file.
         """
 
-        # Handle the max path length depending on the OS
-        try:
-            from ctypes.wintypes import MAX_PATH
-        except ValueError:
-            MAX_PATH = os.pathconf("/", "PC_PATH_MAX")
-
-        if is_urdf is not None:
-            sdf_string = sdf
-        else:
-            match sdf:
-                # Case 1: It's a Path object
-                case pathlib.Path():
-                    sdf_string = sdf.read_text()
-                    is_urdf = sdf.suffix == ".urdf"
-
-                # Case 2: It's a string with a path
-                case str() if len(sdf) <= MAX_PATH and pathlib.Path(sdf).is_file():
-                    sdf_string = pathlib.Path(sdf).read_text(encoding="utf-8")
-                    is_urdf = pathlib.Path(sdf).suffix == ".urdf"
+        path = pathlib.Path(sdf)
 
-                # Case 3: It's an SDF/URDF string
-                case str():
+        match sdf:
+            # Case 1: Handle strings.
+            case str():
+                if path.suffix:
+                    # Assuming that if the string has a suffix, it is a path.
+                    sdf_string = pathlib.Path(sdf).read_text(encoding="utf-8")
+                else:
+                    # Otherwise, it is an SDF string.
                     sdf_string = sdf
-                    is_urdf = "<robot" in sdf_string
 
-                # Case 4: Raise an error for unsupported types
-                case _:
-                    raise TypeError(f"Unsupported type for 'sdf': {type(sdf)}")
+                is_urdf = is_urdf if is_urdf is not None else "<robot" in sdf_string
+
+            # Case 2: Handle pathlib.Path.
+            case pathlib.Path():
+                sdf_string = path.read_text(encoding="utf-8")
+                is_urdf = is_urdf if is_urdf is not None else path.suffix == ".urdf"
+
+            # Case 3: Raise an error for unsupported types.
+            case _:
+                raise TypeError(f"Unsupported type for 'sdf': {type(sdf)}")
 
         # Convert SDF to URDF if needed (it requires system executables)
         if is_urdf:

tests/test_urdf_parsing.py

@@ -1,3 +1,5 @@
+import pathlib
+
 import pytest
 import robot_descriptions
 import robot_descriptions.loaders.idyntree
@@ -35,12 +37,32 @@ def test_urdf_parsing(robot: Robot) -> None:
     with pytest.raises(RuntimeError):
         _ = rod.Sdf.load(sdf=urdf_path.read_text(), is_urdf=False)
 
+    # Check that it fails is is_urdf=True and the resource is a non-existing path
+    with pytest.raises(FileNotFoundError):
+        _ = rod.Sdf.load(sdf="/non/existing/path.sdf", is_urdf=False)
+
+    # Check that it fails is is_urdf=True and the resource is an empty string
+    with pytest.raises(FileNotFoundError):
+        _ = rod.Sdf.load(sdf=pathlib.Path("/non/existing/path.sdf"), is_urdf=False)
+
     # The following instead should succeed
     _ = rod.Sdf.load(sdf=urdf_path, is_urdf=None)
     _ = rod.Sdf.load(sdf=urdf_path, is_urdf=True)
     _ = rod.Sdf.load(sdf=str(urdf_path), is_urdf=None)
     _ = rod.Sdf.load(sdf=str(urdf_path), is_urdf=True)
     _ = rod.Sdf.load(sdf=urdf_path.read_text(), is_urdf=True)
+    _ = rod.Sdf.load(
+        sdf="<robot name='minimal_robot'> \
+                <link name='base_link'/> \
+                <joint name='base_to_link1' type='continuous'> \
+                    <parent link='base_link'/> \
+                    <child link='link1'/> \
+                    <origin xyz='0 0 1' rpy='0 0 0'/> \
+                </joint> \
+                <link name='link1'/> \
+                </robot> \
+    "
+    )
 
     # Load once again the urdf
     rod_sdf = rod.Sdf.load(sdf=urdf_path)