[BUG] fly_to() results in TypeError

[tylere]

Context

What results were you expecting?

I expect the map to fly to the specified state.

Resulting behaviour, error message or logs

Stacktrace:

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
File ~/Documents/GitHub/VorGeo/rle-assessment-report/.pixi/envs/default/lib/python3.11/site-packages/ipywidgets/widgets/widget.py:773, in Widget._handle_msg(self, msg)
    771         if 'buffer_paths' in data:
    772             _put_buffers(state, data['buffer_paths'], msg['buffers'])
--> 773         self.set_state(state)
    775 # Handle a state request.
    776 elif method == 'request_state':

File ~/Documents/GitHub/VorGeo/rle-assessment-report/.pixi/envs/default/lib/python3.11/site-packages/ipywidgets/widgets/widget.py:655, in Widget.set_state(self, sync_data)
    652 if name in self.keys:
    653     from_json = self.trait_metadata(name, 'from_json',
    654                                     self._trait_from_json)
--> 655     self.set_trait(name, from_json(sync_data[name], self))

File ~/Documents/GitHub/VorGeo/rle-assessment-report/.pixi/envs/default/lib/python3.11/site-packages/traitlets/traitlets.py:1764, in HasTraits.set_trait(self, name, value)
   1762 if not self.has_trait(name):
   1763     raise TraitError(f"Class {cls.__name__} does not have a trait named {name}")
-> 1764 getattr(cls, name).set(self, value)

File ~/Documents/GitHub/VorGeo/rle-assessment-report/.pixi/envs/default/lib/python3.11/site-packages/traitlets/traitlets.py:690, in TraitType.set(self, obj, value)
    689 def set(self, obj: HasTraits, value: S) -> None:
--> 690     new_value = self._validate(obj, value)
    691     assert self.name is not None
    692     try:

File ~/Documents/GitHub/VorGeo/rle-assessment-report/.pixi/envs/default/lib/python3.11/site-packages/traitlets/traitlets.py:722, in TraitType._validate(self, obj, value)
    720     return value
    721 if hasattr(self, "validate"):
--> 722     value = self.validate(obj, value)
    723 if obj._cross_validation_lock is False:
    724     value = self._cross_validate(obj, value)

File ~/Documents/GitHub/VorGeo/rle-assessment-report/.pixi/envs/default/lib/python3.11/site-packages/lonboard/traits/_map.py:99, in ViewStateTrait.validate(self, obj, value)
     97 # The frontend currently sends back data in camelCase
     98 snake_case_kwargs = {_camel_to_snake(k): v for k, v in value.items()}
---> 99 return validator(**snake_case_kwargs)

TypeError: MapViewState.__init__() got an unexpected keyword argument 'transition_duration'

Environment

• OS: MacOS 26.0.1 (25A362)
• Browser: not used
• lonboard.version = '0.13.0'
• ipywidgets.version = '8.1.7'
• traitlets.version = '5.14.3'
• Cursor
  • Version: 2.1.25 (Universal)
  • VSCode Version: 1.105.1
  • Commit: 7584ea888f7eb7bf76c9873a8f71b28f034a9820
  • Date: 2025-11-23T04:45:23.529Z (2 wks ago)
  • Electron: 37.7.0
  • Chromium: 138.0.7204.251
  • Node.js: 22.20.0
  • V8: 13.8.258.32-electron.0
  • OS: Darwin arm64 25.0.0

Steps to reproduce the bug

Describe the actions that led you to encounter the bug. Example:

import time
import lonboard
import ipywidgets
import traitlets

print(f'{lonboard.__version__ = }')
print(f'{ipywidgets.__version__ = }')
print(f'{traitlets.__version__ = }')

m = lonboard.Map([])
display(m)
time.sleep(1)
m.fly_to(longitude=10, latitude=10, zoom=5)

[kylebarron]

Thanks for the bug report! I've been heads-down on new features but I'll come back to this in the new year

[vcazacu-axa]

I wanted to test this inside a widget for nice transitions, but hit the same bug :')

[kylebarron]

Would you be able/interested to look into a fix for this?

[tylere]

@kylebarron I took a crack at fixing this with #1123. While it seems to fix the issue, I am not confident in the changes that Claude proposed, due to my limited React skills.