Source code for matplotlib.testing

"""
Helper functions for testing.
"""

import locale
import logging
import subprocess
from pathlib import Path
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 _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{minimal}
            \usepackage{pgf}
            \begin{document}
            \typeout{pgfversion=\pgfversion}
            \makeatletter
            \@@end
        """)
        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):
    return bool(mpl.dviread.find_tex_file(f"{package}.sty"))