from __future__ import absolute_import, division, print_function import six import functools import inspect import os import sys import shutil import warnings import unittest # Note - don't import nose up here - import it only as needed in functions. # This allows other functions here to be used by pytest-based testing suites # without requiring nose to be installed. import matplotlib as mpl import matplotlib.style import matplotlib.units import matplotlib.testing from matplotlib import cbook from matplotlib import ticker from matplotlib import pyplot as plt from matplotlib import ft2font from matplotlib.testing.compare import ( comparable_formats, compare_images, make_test_filename) from . import _copy_metadata, is_called_from_pytest from .exceptions import ImageComparisonFailure def _knownfailureif(fail_condition, msg=None, known_exception_class=None): """ Assume a will fail if *fail_condition* is True. *fail_condition* may also be False or the string 'indeterminate'. *msg* is the error message displayed for the test. If *known_exception_class* is not None, the failure is only known if the exception is an instance of this class. (Default = None) """ if is_called_from_pytest(): import pytest if fail_condition == 'indeterminate': fail_condition, strict = True, False else: fail_condition, strict = bool(fail_condition), True return pytest.mark.xfail(condition=fail_condition, reason=msg, raises=known_exception_class, strict=strict) else: from ._nose.decorators import knownfailureif return knownfailureif(fail_condition, msg, known_exception_class) @cbook.deprecated('2.1', alternative='pytest.xfail or import the plugin') def knownfailureif(fail_condition, msg=None, known_exception_class=None): _knownfailureif(fail_condition, msg, known_exception_class) def _do_cleanup(original_units_registry, original_settings): plt.close('all') mpl.rcParams.clear() mpl.rcParams.update(original_settings) matplotlib.units.registry.clear() matplotlib.units.registry.update(original_units_registry) warnings.resetwarnings() # reset any warning filters set in tests class CleanupTest(object): @classmethod def setup_class(cls): cls.original_units_registry = matplotlib.units.registry.copy() cls.original_settings = mpl.rcParams.copy() matplotlib.testing.setup() @classmethod def teardown_class(cls): _do_cleanup(cls.original_units_registry, cls.original_settings) def test(self): self._func() class CleanupTestCase(unittest.TestCase): '''A wrapper for unittest.TestCase that includes cleanup operations''' @classmethod def setUpClass(cls): import matplotlib.units cls.original_units_registry = matplotlib.units.registry.copy() cls.original_settings = mpl.rcParams.copy() @classmethod def tearDownClass(cls): _do_cleanup(cls.original_units_registry, cls.original_settings) def cleanup(style=None): """ A decorator to ensure that any global state is reset before running a test. Parameters ---------- style : str, optional The name of the style to apply. """ # If cleanup is used without arguments, `style` will be a # callable, and we pass it directly to the wrapper generator. If # cleanup if called with an argument, it is a string naming a # style, and the function will be passed as an argument to what we # return. This is a confusing, but somewhat standard, pattern for # writing a decorator with optional arguments. def make_cleanup(func): if inspect.isgeneratorfunction(func): @functools.wraps(func) def wrapped_callable(*args, **kwargs): original_units_registry = matplotlib.units.registry.copy() original_settings = mpl.rcParams.copy() matplotlib.style.use(style) try: for yielded in func(*args, **kwargs): yield yielded finally: _do_cleanup(original_units_registry, original_settings) else: @functools.wraps(func) def wrapped_callable(*args, **kwargs): original_units_registry = matplotlib.units.registry.copy() original_settings = mpl.rcParams.copy() matplotlib.style.use(style) try: func(*args, **kwargs) finally: _do_cleanup(original_units_registry, original_settings) return wrapped_callable if isinstance(style, six.string_types): return make_cleanup else: result = make_cleanup(style) # Default of mpl_test_settings fixture and image_comparison too. style = '_classic_test' return result def check_freetype_version(ver): if ver is None: return True from distutils import version if isinstance(ver, six.string_types): ver = (ver, ver) ver = [version.StrictVersion(x) for x in ver] found = version.StrictVersion(ft2font.__freetype_version__) return found >= ver[0] and found <= ver[1] def _checked_on_freetype_version(required_freetype_version): if check_freetype_version(required_freetype_version): return lambda f: f reason = ("Mismatched version of freetype. " "Test requires '%s', you have '%s'" % (required_freetype_version, ft2font.__freetype_version__)) return _knownfailureif('indeterminate', msg=reason, known_exception_class=ImageComparisonFailure) def remove_ticks_and_titles(figure): figure.suptitle("") null_formatter = ticker.NullFormatter() for ax in figure.get_axes(): ax.set_title("") ax.xaxis.set_major_formatter(null_formatter) ax.xaxis.set_minor_formatter(null_formatter) ax.yaxis.set_major_formatter(null_formatter) ax.yaxis.set_minor_formatter(null_formatter) try: ax.zaxis.set_major_formatter(null_formatter) ax.zaxis.set_minor_formatter(null_formatter) except AttributeError: pass def _raise_on_image_difference(expected, actual, tol): __tracebackhide__ = True err = compare_images(expected, actual, tol, in_decorator=True) if not os.path.exists(expected): raise ImageComparisonFailure('image does not exist: %s' % expected) if err: for key in ["actual", "expected"]: err[key] = os.path.relpath(err[key]) print( 'images not close (RMS %(rms).3f):\n\t%(actual)s\n\t%(expected)s ' % err) def _xfail_if_format_is_uncomparable(extension): will_fail = extension not in comparable_formats() if will_fail: fail_msg = 'Cannot compare %s files on this system' % extension else: fail_msg = 'No failure expected' return _knownfailureif(will_fail, fail_msg, known_exception_class=ImageComparisonFailure) def _mark_xfail_if_format_is_uncomparable(extension): if isinstance(extension, six.string_types): will_fail = extension not in comparable_formats() else: # Extension might be a pytest marker instead of a plain string. will_fail = extension.args[0] not in comparable_formats() if will_fail: fail_msg = 'Cannot compare %s files on this system' % extension import pytest return pytest.mark.xfail(extension, reason=fail_msg, strict=False, raises=ImageComparisonFailure) else: return extension class _ImageComparisonBase(object): """ Image comparison base class This class provides *just* the comparison-related functionality and avoids any code that would be specific to any testing framework. """ def __init__(self, tol, remove_text, savefig_kwargs): self.func = self.baseline_dir = self.result_dir = None self.tol = tol self.remove_text = remove_text self.savefig_kwargs = savefig_kwargs def delayed_init(self, func): assert self.func is None, "it looks like same decorator used twice" self.func = func self.baseline_dir, self.result_dir = _image_directories(func) def copy_baseline(self, baseline, extension): baseline_path = os.path.join(self.baseline_dir, baseline) orig_expected_fname = baseline_path + '.' + extension if extension == 'eps' and not os.path.exists(orig_expected_fname): orig_expected_fname = baseline_path + '.pdf' expected_fname = make_test_filename( os.path.join(self.result_dir, os.path.basename(orig_expected_fname)), 'expected') if os.path.exists(orig_expected_fname): shutil.copyfile(orig_expected_fname, expected_fname) else: reason = ("Do not have baseline image {0} because this " "file does not exist: {1}".format(expected_fname, orig_expected_fname)) raise ImageComparisonFailure(reason) return expected_fname def compare(self, idx, baseline, extension): __tracebackhide__ = True fignum = plt.get_fignums()[idx] fig = plt.figure(fignum) if self.remove_text: remove_ticks_and_titles(fig) actual_fname = ( os.path.join(self.result_dir, baseline) + '.' + extension) kwargs = self.savefig_kwargs.copy() if extension == 'pdf': kwargs.setdefault('metadata', {'Creator': None, 'Producer': None, 'CreationDate': None}) fig.savefig(actual_fname, **kwargs) expected_fname = self.copy_baseline(baseline, extension) _raise_on_image_difference(expected_fname, actual_fname, self.tol) class ImageComparisonTest(CleanupTest, _ImageComparisonBase): """ Nose-based image comparison class This class generates tests for a nose-based testing framework. Ideally, this class would not be public, and the only publicly visible API would be the :func:`image_comparison` decorator. Unfortunately, there are existing downstream users of this class (e.g., pytest-mpl) so it cannot yet be removed. """ def __init__(self, baseline_images, extensions, tol, freetype_version, remove_text, savefig_kwargs, style): _ImageComparisonBase.__init__(self, tol, remove_text, savefig_kwargs) self.baseline_images = baseline_images self.extensions = extensions self.freetype_version = freetype_version self.style = style def setup(self): func = self.func plt.close('all') self.setup_class() try: matplotlib.style.use(self.style) matplotlib.testing.set_font_settings_for_testing() func() assert len(plt.get_fignums()) == len(self.baseline_images), ( "Test generated {} images but there are {} baseline images" .format(len(plt.get_fignums()), len(self.baseline_images))) except: # Restore original settings before raising errors. self.teardown_class() raise def teardown(self): self.teardown_class() @staticmethod @cbook.deprecated('2.1', alternative='remove_ticks_and_titles') def remove_text(figure): remove_ticks_and_titles(figure) def nose_runner(self): func = self.compare func = _checked_on_freetype_version(self.freetype_version)(func) funcs = {extension: _xfail_if_format_is_uncomparable(extension)(func) for extension in self.extensions} for idx, baseline in enumerate(self.baseline_images): for extension in self.extensions: yield funcs[extension], idx, baseline, extension def __call__(self, func): self.delayed_init(func) import nose.tools @nose.tools.with_setup(self.setup, self.teardown) def runner_wrapper(): for case in self.nose_runner(): yield case return _copy_metadata(func, runner_wrapper) def _pytest_image_comparison(baseline_images, extensions, tol, freetype_version, remove_text, savefig_kwargs, style): """ Decorate function with image comparison for pytest. This function creates a decorator that wraps a figure-generating function with image comparison code. Pytest can become confused if we change the signature of the function, so we indirectly pass anything we need via the `mpl_image_comparison_parameters` fixture and extra markers. """ import pytest extensions = map(_mark_xfail_if_format_is_uncomparable, extensions) def decorator(func): # Parameter indirection; see docstring above and comment below. @pytest.mark.usefixtures('mpl_image_comparison_parameters') @pytest.mark.parametrize('extension', extensions) @pytest.mark.baseline_images(baseline_images) # END Parameter indirection. @pytest.mark.style(style) @_checked_on_freetype_version(freetype_version) @functools.wraps(func) def wrapper(*args, **kwargs): __tracebackhide__ = True img = _ImageComparisonBase(tol=tol, remove_text=remove_text, savefig_kwargs=savefig_kwargs) img.delayed_init(func) matplotlib.testing.set_font_settings_for_testing() func(*args, **kwargs) # Parameter indirection: # This is hacked on via the mpl_image_comparison_parameters fixture # so that we don't need to modify the function's real signature for # any parametrization. Modifying the signature is very very tricky # and likely to confuse pytest. baseline_images, extension = func.parameters assert len(plt.get_fignums()) == len(baseline_images), ( "Test generated {} images but there are {} baseline images" .format(len(plt.get_fignums()), len(baseline_images))) for idx, baseline in enumerate(baseline_images): img.compare(idx, baseline, extension) wrapper.__wrapped__ = func # For Python 2.7. return _copy_metadata(func, wrapper) return decorator def image_comparison(baseline_images, extensions=None, tol=0.306, freetype_version=None, remove_text=False, savefig_kwarg=None, # Default of mpl_test_settings fixture and cleanup too. style='_classic_test'): """ Compare images generated by the test with those specified in *baseline_images*, which must correspond else an ImageComparisonFailure exception will be raised. Arguments --------- baseline_images : list or None A list of strings specifying the names of the images generated by calls to :meth:`matplotlib.figure.savefig`. If *None*, the test function must use the ``baseline_images`` fixture, either as a parameter or with pytest.mark.usefixtures. This value is only allowed when using pytest. extensions : [ None | list ] If None, defaults to all supported extensions. Otherwise, a list of extensions to test. For example ['png','pdf']. tol : float, optional, default: 0 The RMS threshold above which the test is considered failed. freetype_version : str or tuple The expected freetype version or range of versions for this test to pass. remove_text : bool Remove the title and tick text from the figure before comparison. This does not remove other, more deliberate, text, such as legends and annotations. savefig_kwarg : dict Optional arguments that are passed to the savefig method. style : string Optional name for the base style to apply to the image test. The test itself can also apply additional styles if desired. Defaults to the '_classic_test' style. """ if extensions is None: # default extensions to test extensions = ['png', 'pdf', 'svg'] if savefig_kwarg is None: #default no kwargs to savefig savefig_kwarg = dict() if is_called_from_pytest(): return _pytest_image_comparison( baseline_images=baseline_images, extensions=extensions, tol=tol, freetype_version=freetype_version, remove_text=remove_text, savefig_kwargs=savefig_kwarg, style=style) else: if baseline_images is None: raise ValueError('baseline_images must be specified') return ImageComparisonTest( baseline_images=baseline_images, extensions=extensions, tol=tol, freetype_version=freetype_version, remove_text=remove_text, savefig_kwargs=savefig_kwarg, style=style) def _image_directories(func): """ Compute the baseline and result image directories for testing *func*. Create the result directory if it doesn't exist. """ module_name = func.__module__ if module_name == '__main__': # FIXME: this won't work for nested packages in matplotlib.tests warnings.warn( 'Test module run as script. Guessing baseline image locations.') script_name = sys.argv[0] basedir = os.path.abspath(os.path.dirname(script_name)) subdir = os.path.splitext(os.path.split(script_name)[1])[0] else: mods = module_name.split('.') if len(mods) >= 3: mods.pop(0) # mods[0] will be the name of the package being tested (in # most cases "matplotlib") However if this is a # namespace package pip installed and run via the nose # multiprocess plugin or as a specific test this may be # missing. See https://github.com/matplotlib/matplotlib/issues/3314 if mods.pop(0) != 'tests': warnings.warn( "Module {!r} does not live in a parent module named 'tests'. " "This is probably ok, but we may not be able to guess the " "correct subdirectory containing the baseline images. If " "things go wrong please make sure that there is a parent " "directory named 'tests' and that it contains a __init__.py " "file (can be empty).".format(module_name)) subdir = os.path.join(*mods) import imp def find_dotted_module(module_name, path=None): """A version of imp which can handle dots in the module name. As for imp.find_module(), the return value is a 3-element tuple (file, pathname, description).""" res = None for sub_mod in module_name.split('.'): try: res = file, path, _ = imp.find_module(sub_mod, path) path = [path] if file is not None: file.close() except ImportError: # assume namespace package path = list(sys.modules[sub_mod].__path__) res = None, path, None return res mod_file = find_dotted_module(func.__module__)[1] basedir = os.path.dirname(mod_file) baseline_dir = os.path.join(basedir, 'baseline_images', subdir) result_dir = os.path.abspath(os.path.join('result_images', subdir)) if not os.path.exists(result_dir): cbook.mkdirs(result_dir) return baseline_dir, result_dir def switch_backend(backend): # Local import to avoid a hard nose dependency and only incur the # import time overhead at actual test-time. def switch_backend_decorator(func): @functools.wraps(func) def backend_switcher(*args, **kwargs): try: prev_backend = mpl.get_backend() matplotlib.testing.setup() plt.switch_backend(backend) result = func(*args, **kwargs) finally: plt.switch_backend(prev_backend) return result return _copy_metadata(func, backend_switcher) return switch_backend_decorator def skip_if_command_unavailable(cmd): """ skips a test if a command is unavailable. Parameters ---------- cmd : list of str must be a complete command which should not return a non zero exit code, something like ["latex", "-version"] """ from matplotlib.compat.subprocess import check_output try: check_output(cmd) except: import pytest return pytest.mark.skip(reason='missing command: %s' % cmd[0]) return lambda f: f