the-littlest-jupyterhub/integration-tests/test_extensions.py

import subprocess


def test_serverextensions():
    """
    Validate serverextensions we want are installed
    """
    # jupyter-serverextension writes to stdout and stderr weirdly
    proc = subprocess.run([
        '/opt/tljh/user/bin/jupyter-serverextension',
        'list', '--sys-prefix'
    ], stderr=subprocess.PIPE)

    extensions = [
        'jupyterlab 3.',
        'nbgitpuller 1.',
        'nteract_on_jupyter 2.1.',
        'jupyter_resource_usage'
    ]

    for e in extensions:
        assert e in proc.stderr.decode()

def test_nbextensions():
    """
    Validate nbextensions we want are installed & enabled
    """
    # jupyter-nbextension writes to stdout and stderr weirdly
    proc = subprocess.run([
        '/opt/tljh/user/bin/jupyter-nbextension',
        'list', '--sys-prefix'
    ], stderr=subprocess.PIPE, stdout=subprocess.PIPE)

    extensions = [
        'jupyter_resource_usage/main',
        # This is what ipywidgets nbextension is called
        'jupyter-js-widgets/extension'
    ]

    for e in extensions:
        assert f'{e} \x1b[32m enabled \x1b[0m' in proc.stdout.decode()

    # Ensure we have 'OK' messages in our stdout, to make sure everything is importable
    assert proc.stderr.decode() == '      - Validating: \x1b[32mOK\x1b[0m\n' * len(extensions)