test_examples.py

import os
import runpy
from pathlib import Path

import pytest
from qtpy import API_NAME

import napari
from napari.utils.notifications import notification_manager

from napari._tests.utils import slow

# not testing these examples
skip = [
    'surface_timeseries.py',  # needs nilearn
    '3d_kymograph.py',  # needs tqdm
    'live_tiffs.py',  # requires files
    'tiled-rendering-2d.py',  # too slow
    'live_tiffs_generator.py',
    'points-over-time.py',  # too resource hungry
    'embed_ipython.py',  # fails without monkeypatch
    'custom_key_bindings.py',  # breaks EXPECTED_NUMBER_OF_VIEWER_METHODS later
    'new_theme.py',  # testing theme is extremely slow on CI
]


if os.environ.get('MIN_REQ', '') == '1':
    skip.extend(['spheres.py', 'clipping_planes_interactive.py'])

EXAMPLE_DIR = Path(napari.__file__).parent.parent / 'examples'
# using f.name here and re-joining at `run_path()` for test key presentation
# (works even if the examples list is empty, as opposed to using an ids lambda)
examples = [f.name for f in EXAMPLE_DIR.glob("*.py") if f.name not in skip]

# still some CI segfaults, but only on windows with pyqt5
if os.getenv("CI") and os.name == 'nt' and API_NAME == 'PyQt5':
    examples = []

if os.getenv("CI") and os.name == 'nt':
    if 'to_screenshot.py' in examples:
        examples.remove('to_screenshot.py')


@pytest.fixture
def qapp():
    from qtpy.QtCore import QTimer

    from napari._qt.qt_event_loop import get_app

    # it's important that we use get_app so that it connects to the
    # app.aboutToQuit.connect(wait_for_workers_to_quit)
    app = get_app()

    # quit examples that explicitly start the event loop with `napari.run()`
    # so that tests aren't waiting on a manual exit
    QTimer.singleShot(100, app.quit)

    yield app


@slow(30)
@pytest.mark.filterwarnings("ignore")
@pytest.mark.skipif(not examples, reason="No examples were found.")
@pytest.mark.parametrize("fname", examples)
def test_examples(qapp, fname, monkeypatch, capsys):
    """Test that all of our examples are still working without warnings."""

    from napari._qt.qt_main_window import Window

    # hide viewer window
    monkeypatch.setattr(Window, 'show', lambda *a: None)

    # make sure our sys.excepthook override doesn't hide errors
    def raise_errors(etype, value, tb):
        raise value

    monkeypatch.setattr(notification_manager, 'receive_error', raise_errors)

    # run the example!
    try:
        runpy.run_path(str(EXAMPLE_DIR / fname))
    except SystemExit as e:
        # we use sys.exit(0) to gracefully exit from examples
        if e.code != 0:
            raise