Clear cached property when validation is off

tests/test_components/test_base.py

@@ -115,6 +115,14 @@ def test_updated_copy():
     assert s3 == s2
 
 
+def test_cached_property_unvalidated_copy():
+    """Make sure cached property is cleared when copied without validation."""
+    b = td.Box(size=(1, 1, 1))
+    _ = b.bounds
+    c = b.updated_copy(size=(2, 2, 2), validate=False)
+    assert c.bounds[0][0] == -1
+
+
 def test_updated_copy_path():
     """Make sure updated copying shortcut works as expected with defaults."""
     b = td.Box(size=(1, 1, 1))

tidy3d/components/base.py

@@ -222,6 +222,9 @@ def copy(self, deep: bool = True, validate: bool = True, **kwargs) -> Tidy3dBase
         new_copy = pydantic.BaseModel.copy(self, **kwargs)
         if validate:
             return self.validate(new_copy.dict())
+        # cached property is cleared automatically when validation is on, but it
+        # needs to be manually cleared when validation is off
+        new_copy._cached_properties = {}
         return new_copy
 
     def updated_copy(