"""

Helper functions for testing.

"""

import itertools

import locale

import logging

import os

from pathlib import Path

import string

import subprocess

import sys

from tempfile import TemporaryDirectory

import matplotlib as mpl

from matplotlib import _api

_log = logging.getLogger(__name__)

def set_font_settings_for_testing():

mpl.rcParams['font.family'] = 'DejaVu Sans'

mpl.rcParams['text.hinting'] = 'none'

mpl.rcParams['text.hinting_factor'] = 8

def set_reproducibility_for_testing():

mpl.rcParams['svg.hashsalt'] = 'matplotlib'

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()

def subprocess_run_for_testing(command, env=None, timeout=60, stdout=None,

stderr=None, check=False, text=True,

capture_output=False, **kwargs):

"""

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.skip

If running on emscripten, which does not support subprocesses.

pytest.xfail

If platform is Cygwin and subprocess reports a fork() failure.

"""

if sys.platform == 'emscripten':

import pytest

pytest.skip('emscripten does not support subprocesses')

if capture_output:

stdout = stderr = subprocess.PIPE

# Add CREATE_NO_WINDOW flag on Windows to prevent console window overhead

# This is added in an attempt to fix flaky timeouts of subprocesses on Windows

if sys.platform == 'win32':

if 'creationflags' not in kwargs:

kwargs['creationflags'] = subprocess.CREATE_NO_WINDOW

else:

kwargs['creationflags'] |= subprocess.CREATE_NO_WINDOW

try:

proc = subprocess.run(

command, env=env,

timeout=timeout, check=check,

stdout=stdout, stderr=stderr,

text=text, **kwargs

)

except BlockingIOError:

if sys.platform == "cygwin":

# Might want to make this more specific

import pytest

pytest.xfail("Fork failure")

raise

except subprocess.CalledProcessError as e:

if e.stdout:

_log.error(f"Subprocess output:\n{e.stdout}")

if e.stderr:

_log.error(f"Subprocess error:\n{e.stderr}")

raise e

if proc.stdout:

_log.debug(f"Subprocess output:\n{proc.stdout}")

if proc.stderr:

_log.debug(f"Subprocess error:\n{proc.stderr}")

return proc

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",

# subprocess_run_helper sets SOURCE_DATE_EPOCH=0 above, so for a dirty tree,

# the version will have the date 19700101 which breaks pickle tests with a

# warning if the working tree is dirty.

#

# This will also avoid at least one additional subprocess call for

# setuptools-scm query git, so we tell the subprocess what version

# to report as the test process.

"SETUPTOOLS_SCM_PRETEND_VERSION_FOR_MATPLOTLIB": mpl.__version__,

**(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", "-no-shell-escape",

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, OSError):

return False

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}'")

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

def _gen_multi_font_text():

"""

Generate text intended for use with multiple fonts to exercise font fallbacks.

Returns

-------

fonts : list of str

The names of the fonts used to render the test string, sorted by intended

priority. This should be set as the font family for the Figure or Text artist.

text : str

The test string.

"""

# These fonts are serif and sans-serif, and would not normally be combined, but that

# should make it easier to see which glyph is from which font.

fonts = ['cmr10', 'DejaVu Sans']

# cmr10 does not contain accented characters, so they should fall back to DejaVu

# Sans. However, some accented capital A versions *are* in cmr10 with non-standard

# glyph shapes, so don't test those (otherwise this Latin1 supplement group would

# start at 0xA0.)

start = 0xC5

latin1_supplement = [chr(x) for x in range(start, 0xFF+1)]

latin_extended_A = [chr(x) for x in range(0x100, 0x17F+1)]

latin_extended_B = [chr(x) for x in range(0x180, 0x24F+1)]

count = itertools.count(start - 0xA0)

non_basic_characters = '\n'.join(

''.join(line)

for _, line in itertools.groupby( # Replace with itertools.batched for Py3.12+.

[*latin1_supplement, *latin_extended_A, *latin_extended_B],

key=lambda x: next(count) // 32) # 32 characters per line.

)

test_str = f"""There are basic characters

{string.ascii_uppercase} {string.ascii_lowercase}

{string.digits} {string.punctuation}

and accented characters

{non_basic_characters}

in between!"""

# The resulting string contains 491 unique characters. Some file formats use 8-bit

# tables, which the large number of characters exercises twice over.

return fonts, test_str