Test failure in ipywidgets 8

[jasongrout]

@frenzymadness reported that nbclient tests fail when using the upcoming ipywidgets 8. The test notebook should be updated to reflect the change, as it is an expected change in ipywidgets behavior in ipywidgets 8.

See jupyter-widgets/ipywidgets#2750 (comment) and jupyter-widgets/ipywidgets#2750 (comment) for a short discussion of the issue.

[jasongrout]

For convenience, here is the failure:

=================================== FAILURES ===================================
______________ test_run_all_notebooks[JupyterWidgets.ipynb-opts7] ______________

input_name = 'JupyterWidgets.ipynb', opts = {'kernel_name': 'python'}

    @pytest.mark.parametrize(
        ["input_name", "opts"],
        [
            ("Other Comms.ipynb", dict(kernel_name="python")),
            ("Clear Output.ipynb", dict(kernel_name="python")),
            ("Empty Cell.ipynb", dict(kernel_name="python")),
            ("Factorials.ipynb", dict(kernel_name="python")),
            ("HelloWorld.ipynb", dict(kernel_name="python")),
            ("Inline Image.ipynb", dict(kernel_name="python")),
            (
                "Interrupt.ipynb",
                dict(kernel_name="python", timeout=1, interrupt_on_timeout=True, allow_errors=True),
            ),
            ("JupyterWidgets.ipynb", dict(kernel_name="python")),
            ("Skip Exceptions with Cell Tags.ipynb", dict(kernel_name="python")),
            ("Skip Exceptions.ipynb", dict(kernel_name="python", allow_errors=True)),
            ("Skip Execution with Cell Tag.ipynb", dict(kernel_name="python")),
            ("SVG.ipynb", dict(kernel_name="python")),
            ("Unicode.ipynb", dict(kernel_name="python")),
            ("UnicodePy3.ipynb", dict(kernel_name="python")),
            ("update-display-id.ipynb", dict(kernel_name="python")),
            ("Check History in Memory.ipynb", dict(kernel_name="python")),
        ],
    )
    def test_run_all_notebooks(input_name, opts):
        """Runs a series of test notebooks and compares them to their actual output"""
        input_file = os.path.join(current_dir, 'files', input_name)
        input_nb, output_nb = run_notebook(input_file, opts, notebook_resources())
>       assert_notebooks_equal(input_nb, output_nb)

nbclient/tests/test_client.py:333: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

expected = {'cells': [{'cell_type': 'code', 'execution_count': 1, 'metadata': {}, 'outputs': [{'data': {'application/vnd.jupyter....del_name': 'LayoutModel', 'state': {}}}, 'version_major': 2, 'version_minor': 0}}}, 'nbformat': 4, 'nbformat_minor': 2}
actual = {'cells': [{'cell_type': 'code', 'metadata': {'execution': {'iopub.status.busy': '2022-08-09T19:28:42.615167Z', 'iopub...oltip': None, 'value': 'Hello World'}}}, 'version_major': 2, 'version_minor': 0}}}, 'nbformat': 4, 'nbformat_minor': 2}

    def assert_notebooks_equal(expected, actual):
        expected_cells = expected['cells']
        actual_cells = actual['cells']
        assert len(expected_cells) == len(actual_cells)
    
        for expected_cell, actual_cell in zip(expected_cells, actual_cells):
            # Uncomment these to help debug test failures better
            # from pprint import pprint
            # pprint(expected_cell)
            # pprint(actual_cell)
            expected_outputs = expected_cell.get('outputs', [])
            actual_outputs = actual_cell.get('outputs', [])
            normalized_expected_outputs = list(map(normalize_output, expected_outputs))
            normalized_actual_outputs = list(map(normalize_output, actual_outputs))
>           assert normalized_expected_outputs == normalized_actual_outputs
E           AssertionError: assert [{'data': {'application/vnd.jupyter.widget-view+json': {'model_id': '<MODEL_ID>',\n                                                        'version_major': 2,\n                                                        'version_minor': 0},\n           'text/plain': 'LabelvalueHelloWorld'},\n  'output_type': 'display_data'}] == [{'data': {'application/vnd.jupyter.widget-view+json': {'model_id': '<MODEL_ID>',\n                                                        'version_major': 2,\n                                                        'version_minor': 0},\n           'text/plain': 'LabelvalueHelloWorld'},\n  'execution_count': 1,\n  'output_type': 'execute_result'}]
E             At index 0 diff: {'data': {'application/vnd.jupyter.widget-view+json': {'model_id': '<MODEL_ID>', 'version_major': 2, 'version_minor': 0}, 'text/plain': 'LabelvalueHelloWorld'}, 'output_type': 'display_data'} != {'output_type': 'execute_result', 'data': {'text/plain': 'LabelvalueHelloWorld', 'application/vnd.jupyter.widget-view+json': {'version_major': 2, 'version_minor': 0, 'model_id': '<MODEL_ID>'}}, 'execution_count': 1}
E             Full diff:
E               [
E                {'data': {'application/vnd.jupyter.widget-view+json': {'model_id': '<MODEL_ID>',
E                                                                       'version_major': 2,
E                                                                       'version_minor': 0},
E                          'text/plain': 'LabelvalueHelloWorld'},
E             +   'output_type': 'display_data'},
E             -   'execution_count': 1,
E             -   'output_type': 'execute_result'},
E               ]

nbclient/tests/test_client.py:280: AssertionError

[jasongrout]

Alternatively, I think you can change the code of that cell to display(widget) instead of relying on the automatic display of the widget, which I think should give the same output for ipywidgets 7 or ipywidgets 8.