LSR/env/lib/python3.6/site-packages/matplotlib/tests/test_backends_interactive.py
2020-06-04 17:24:47 +02:00

146 lines
4.9 KiB
Python

import importlib
import importlib.util
import os
import signal
import subprocess
import sys
import time
import urllib.request
import pytest
import matplotlib as mpl
# Minimal smoke-testing of the backends for which the dependencies are
# PyPI-installable on Travis. They are not available for all tested Python
# versions so we don't fail on missing backends.
def _get_testable_interactive_backends():
backends = []
for deps, backend in [
(["cairo", "gi"], "gtk3agg"),
(["cairo", "gi"], "gtk3cairo"),
(["PyQt5"], "qt5agg"),
(["PyQt5", "cairocffi"], "qt5cairo"),
(["tkinter"], "tkagg"),
(["wx"], "wx"),
(["wx"], "wxagg"),
]:
reason = None
if not os.environ.get("DISPLAY"):
reason = "No $DISPLAY"
elif any(importlib.util.find_spec(dep) is None for dep in deps):
reason = "Missing dependency"
if reason:
backend = pytest.param(
backend, marks=pytest.mark.skip(reason=reason))
backends.append(backend)
return backends
# Using a timer not only allows testing of timers (on other backends), but is
# also necessary on gtk3 and wx, where a direct call to key_press_event("q")
# from draw_event causes breakage due to the canvas widget being deleted too
# early. Also, gtk3 redefines key_press_event with a different signature, so
# we directly invoke it from the superclass instead.
_test_script = """\
import importlib
import importlib.util
import sys
from unittest import TestCase
import matplotlib as mpl
from matplotlib import pyplot as plt, rcParams
from matplotlib.backend_bases import FigureCanvasBase
rcParams.update({
"webagg.open_in_browser": False,
"webagg.port_retries": 1,
})
backend = plt.rcParams["backend"].lower()
assert_equal = TestCase().assertEqual
assert_raises = TestCase().assertRaises
if backend.endswith("agg") and not backend.startswith(("gtk3", "web")):
# Force interactive framework setup.
plt.figure()
# Check that we cannot switch to a backend using another interactive
# framework, but can switch to a backend using cairo instead of agg, or a
# non-interactive backend. In the first case, we use tkagg as the "other"
# interactive backend as it is (essentially) guaranteed to be present.
# Moreover, don't test switching away from gtk3 (as Gtk.main_level() is
# not set up at this point yet) and webagg (which uses no interactive
# framework).
if backend != "tkagg":
with assert_raises(ImportError):
mpl.use("tkagg", force=True)
def check_alt_backend(alt_backend):
mpl.use(alt_backend, force=True)
fig = plt.figure()
assert_equal(
type(fig.canvas).__module__,
"matplotlib.backends.backend_{}".format(alt_backend))
if importlib.util.find_spec("cairocffi"):
check_alt_backend(backend[:-3] + "cairo")
check_alt_backend("svg")
mpl.use(backend, force=True)
fig, ax = plt.subplots()
assert_equal(
type(fig.canvas).__module__,
"matplotlib.backends.backend_{}".format(backend))
ax.plot([0, 1], [2, 3])
timer = fig.canvas.new_timer(1)
timer.add_callback(FigureCanvasBase.key_press_event, fig.canvas, "q")
# Trigger quitting upon draw.
fig.canvas.mpl_connect("draw_event", lambda event: timer.start())
plt.show()
"""
_test_timeout = 10 # Empirically, 1s is not enough on Travis.
@pytest.mark.parametrize("backend", _get_testable_interactive_backends())
@pytest.mark.flaky(reruns=3)
def test_interactive_backend(backend):
proc = subprocess.run([sys.executable, "-c", _test_script],
env={**os.environ, "MPLBACKEND": backend},
timeout=_test_timeout)
if proc.returncode:
pytest.fail("The subprocess returned with non-zero exit status "
f"{proc.returncode}.")
@pytest.mark.skipif('SYSTEM_TEAMFOUNDATIONCOLLECTIONURI' in os.environ,
reason="this test fails an azure for unknown reasons")
@pytest.mark.skipif(os.name == "nt", reason="Cannot send SIGINT on Windows.")
def test_webagg():
pytest.importorskip("tornado")
proc = subprocess.Popen([sys.executable, "-c", _test_script],
env={**os.environ, "MPLBACKEND": "webagg"})
url = "http://{}:{}".format(
mpl.rcParams["webagg.address"], mpl.rcParams["webagg.port"])
timeout = time.perf_counter() + _test_timeout
while True:
try:
retcode = proc.poll()
# check that the subprocess for the server is not dead
assert retcode is None
conn = urllib.request.urlopen(url)
break
except urllib.error.URLError:
if time.perf_counter() > timeout:
pytest.fail("Failed to connect to the webagg server.")
else:
continue
conn.close()
proc.send_signal(signal.SIGINT)
assert proc.wait(timeout=_test_timeout) == 0