"""
Helper functions for testing.
"""
from pathlib import Path
from tempfile import TemporaryDirectory
import locale
import logging
import os
import subprocess
import sys
import matplotlib as mpl
from matplotlib import _api
_log = logging.getLogger(__name__)
[docs]
def set_font_settings_for_testing():
mpl.rcParams['font.family'] = 'DejaVu Sans'
mpl.rcParams['text.hinting'] = 'none'
mpl.rcParams['text.hinting_factor'] = 8
[docs]
def set_reproducibility_for_testing():
mpl.rcParams['svg.hashsalt'] = 'matplotlib'
[docs]
def setup():
# The baseline images are created in this locale, so we should use
# it during all of the tests.
try:
locale.setlocale(locale.LC_ALL, 'en_US.UTF-8')
except locale.Error:
try:
locale.setlocale(locale.LC_ALL, 'English_United States.1252')
except locale.Error:
_log.warning(
"Could not set locale to English/United States. "
"Some date-related tests may fail.")
mpl.use('Agg')
with _api.suppress_matplotlib_deprecation_warning():
mpl.rcdefaults() # Start with all defaults
# These settings *must* be hardcoded for running the comparison tests and
# are not necessarily the default values as specified in rcsetup.py.
set_font_settings_for_testing()
set_reproducibility_for_testing()
[docs]
def subprocess_run_for_testing(command, env=None, timeout=60, stdout=None,
stderr=None, check=False, text=True,
capture_output=False):
"""
Create and run a subprocess.
Thin wrapper around `subprocess.run`, intended for testing. Will
mark fork() failures on Cygwin as expected failures: not a
success, but not indicating a problem with the code either.
Parameters
----------
args : list of str
env : dict[str, str]
timeout : float
stdout, stderr
check : bool
text : bool
Also called ``universal_newlines`` in subprocess. I chose this
name since the main effect is returning bytes (`False`) vs. str
(`True`), though it also tries to normalize newlines across
platforms.
capture_output : bool
Set stdout and stderr to subprocess.PIPE
Returns
-------
proc : subprocess.Popen
See Also
--------
subprocess.run
Raises
------
pytest.xfail
If platform is Cygwin and subprocess reports a fork() failure.
"""
if capture_output:
stdout = stderr = subprocess.PIPE
try:
proc = subprocess.run(
command, env=env,
timeout=timeout, check=check,
stdout=stdout, stderr=stderr,
text=text
)
except BlockingIOError:
if sys.platform == "cygwin":
# Might want to make this more specific
import pytest
pytest.xfail("Fork failure")
raise
return proc
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def subprocess_run_helper(func, *args, timeout, extra_env=None):
"""
Run a function in a sub-process.
Parameters
----------
func : function
The function to be run. It must be in a module that is importable.
*args : str
Any additional command line arguments to be passed in
the first argument to ``subprocess.run``.
extra_env : dict[str, str]
Any additional environment variables to be set for the subprocess.
"""
target = func.__name__
module = func.__module__
file = func.__code__.co_filename
proc = subprocess_run_for_testing(
[
sys.executable,
"-c",
f"import importlib.util;"
f"_spec = importlib.util.spec_from_file_location({module!r}, {file!r});"
f"_module = importlib.util.module_from_spec(_spec);"
f"_spec.loader.exec_module(_module);"
f"_module.{target}()",
*args
],
env={**os.environ, "SOURCE_DATE_EPOCH": "0", **(extra_env or {})},
timeout=timeout, check=True,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
text=True
)
return proc
def _check_for_pgf(texsystem):
"""
Check if a given TeX system + pgf is available
Parameters
----------
texsystem : str
The executable name to check
"""
with TemporaryDirectory() as tmpdir:
tex_path = Path(tmpdir, "test.tex")
tex_path.write_text(r"""
\documentclass{article}
\usepackage{pgf}
\begin{document}
\typeout{pgfversion=\pgfversion}
\makeatletter
\@@end
""", encoding="utf-8")
try:
subprocess.check_call(
[texsystem, "-halt-on-error", str(tex_path)], cwd=tmpdir,
stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
except (OSError, subprocess.CalledProcessError):
return False
return True
def _has_tex_package(package):
try:
mpl.dviread.find_tex_file(f"{package}.sty")
return True
except FileNotFoundError:
return False
[docs]
def ipython_in_subprocess(requested_backend_or_gui_framework, all_expected_backends):
import pytest
IPython = pytest.importorskip("IPython")
if sys.platform == "win32":
pytest.skip("Cannot change backend running IPython in subprocess on Windows")
if (IPython.version_info[:3] == (8, 24, 0) and
requested_backend_or_gui_framework == "osx"):
pytest.skip("Bug using macosx backend in IPython 8.24.0 fixed in 8.24.1")
# This code can be removed when Python 3.12, the latest version supported
# by IPython < 8.24, reaches end-of-life in late 2028.
for min_version, backend in all_expected_backends.items():
if IPython.version_info[:2] >= min_version:
expected_backend = backend
break
code = ("import matplotlib as mpl, matplotlib.pyplot as plt;"
"fig, ax=plt.subplots(); ax.plot([1, 3, 2]); mpl.get_backend()")
proc = subprocess_run_for_testing(
[
"ipython",
"--no-simple-prompt",
f"--matplotlib={requested_backend_or_gui_framework}",
"-c", code,
],
check=True,
capture_output=True,
)
assert proc.stdout.strip().endswith(f"'{expected_backend}'")
[docs]
def is_ci_environment():
# Common CI variables
ci_environment_variables = [
'CI', # Generic CI environment variable
'CONTINUOUS_INTEGRATION', # Generic CI environment variable
'TRAVIS', # Travis CI
'CIRCLECI', # CircleCI
'JENKINS', # Jenkins
'GITLAB_CI', # GitLab CI
'GITHUB_ACTIONS', # GitHub Actions
'TEAMCITY_VERSION' # TeamCity
# Add other CI environment variables as needed
]
for env_var in ci_environment_variables:
if os.getenv(env_var):
return True
return False
