Make notify_frontend required (no default) in set_ui_element_value

[Copilot]

The notify_frontend kwarg added to set_ui_element_value had a = False default, leaving call sites implicitly opted out. Making it required forces every caller to be explicit about intent.

Changes

• Removed = False default from notify_frontend in all four layers of the call chain:
  • Kernel.set_ui_element_value (runtime.py)
  • AppKernelRunner.set_ui_element_value (kernel_runner.py)
  • InternalApp._set_ui_element_value / AppKernelRunner.set_ui_element_value (app.py)
• Explicitly passed notify_frontend=False at all previously-implicit call sites:
  • handle_set_ui_element_value — user-initiated frontend update
  • handle_receive_model_message — widget comm update
  • All test call sites across test_runtime, test_app, test_cell_runner, test_refresh, test_run_button, test_anywidget
• _code_mode/_context.py already passes notify_frontend=True explicitly — no change needed

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Project	Deployment	Actions	Updated (UTC)
marimo-docs	Ready	Preview, Comment	Apr 19, 2026 0:39am

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