Support slash notation for BlendPath

This mimicks the slash notation of pathlib.Path

blender_asset_tracer/bpathlib.py

@@ -25,6 +25,19 @@ class BlendPath(bytes):
         """
         return self.decode('utf8', errors='replace')
 
+    def __truediv__(self, subpath: bytes):
+        """Slash notation like pathlib.Path."""
+        sub = BlendPath(subpath)
+        if sub.is_absolute():
+            raise ValueError("'a / b' only works when 'b' is a relative path")
+        return BlendPath(os.path.join(self, sub))
+
+    def __rtruediv__(self, parentpath: bytes):
+        """Slash notation like pathlib.Path."""
+        if self.is_absolute():
+            raise ValueError("'a / b' only works when 'b' is a relative path")
+        return BlendPath(os.path.join(parentpath, self))
+
     def is_blendfile_relative(self) -> bool:
         return self[:2] == b'//'
 

tests/test_bpathlib.py

@@ -42,3 +42,12 @@ class BlendPathTest(unittest.TestCase):
                          BlendPath(b'../some/file.blend').absolute(b'/root/to'))
         self.assertEqual(b'/shared/some/file.blend',
                          BlendPath(b'/shared/some/file.blend').absolute(b'/root/to'))
+
+    def test_slash(self):
+        self.assertEqual(b'/root/and/parent.blend', BlendPath(b'/root/and') / b'parent.blend')
+        with self.assertRaises(ValueError):
+            BlendPath(b'/root/and') / b'/parent.blend'
+
+        self.assertEqual(b'/root/and/parent.blend', b'/root/and' / BlendPath(b'parent.blend'))
+        with self.assertRaises(ValueError):
+            b'/root/and' / BlendPath(b'/parent.blend')