monkeyking/notebook/tests/selenium/interrupt.py

from selenium.webdriver.common.keys import Keys
from .utils import wait_for_selector
from functools import wraps
import errno
import os
import signal

class TimeoutError(Exception):
    pass

def timeout(seconds=10, error_message=os.strerror(errno.ETIME)):
    def decorator(func):
        def _handle_timeout(signum, frame):
            raise TimeoutError(error_message)

        def wrapper(*args, **kwargs):
            signal.signal(signal.SIGALRM, _handle_timeout)
            signal.alarm(seconds)
            try:
                result = func(*args, **kwargs)
            finally:
                signal.alarm(0)
            return result

        return wraps(func)(wrapper)

    return decorator

@timeout(15)
def test_interrupt(notebook):
    """ Test the interrupt function using both the button in the Kernel menu and the keyboard shortcut "ii"

        Having trouble accessing the Interrupt message when execution is halted. I am assuming that the
        message does not lie in the "outputs" field of the cell's JSON object. Using a timeout work-around for
        test with an infinite loop. We know the interrupt function is working if this test passes.
        Hope this is a good start.
    """

    text = 'import time'+'\nwhile(1):'+'\n    for x in range(3):'+'\n        time.sleep(1)'

    notebook.edit_cell(index=0, content=text)
    notebook.to_command_mode()
    notebook.execute_cell(0)

    # Click interrupt button in kernel menu
    kernel_button = wait_for_selector(notebook.browser, '#menus > div > div > ul > li:nth-child(6) > a', single=True)
    kernel_button.click()
    int_button = wait_for_selector(notebook.browser, '#int_kernel > a', single=True)
    int_button.click()

    # outputs = get_cells_output(notebook, 0)
    # assert outputs.find("KeyboardInterrupt") != -1

    # Clear output and repeat execution
    notebook.clear_cells_output(0)
    notebook.to_command_mode()
    notebook.execute_cell(0)

    # Send interrupt shortcut via keyboard
    notebook.body.send_keys(Keys.ESCAPE)
    notebook.body.send_keys("ii")

    # outputs = get_cells_output(notebook, 0)
    # assert outputs.find("KeyboardInterrupt") != -1