""" Testing utilities. """ import os import re import struct import threading import functools from tempfile import NamedTemporaryFile import numpy as np from numpy import testing from numpy.testing import (assert_array_equal, assert_array_almost_equal, assert_array_less, assert_array_almost_equal_nulp, assert_equal, TestCase, assert_allclose, assert_almost_equal, assert_, assert_warns, assert_no_warnings) from ._warnings import expected_warnings import warnings from .. import data, io, img_as_uint, img_as_float, img_as_int, img_as_ubyte import pytest SKIP_RE = re.compile("(\s*>>>.*?)(\s*)#\s*skip\s+if\s+(.*)$") skipif = pytest.mark.skipif xfail = pytest.mark.xfail parametrize = pytest.mark.parametrize raises = pytest.raises fixture = pytest.fixture # true if python is running in 32bit mode # Calculate the size of a void * pointer in bits # https://docs.python.org/2/library/struct.html arch32 = struct.calcsize("P") * 8 == 32 def assert_less(a, b, msg=None): message = "%r is not lower than %r" % (a, b) if msg is not None: message += ": " + msg assert a < b, message def assert_greater(a, b, msg=None): message = "%r is not greater than %r" % (a, b) if msg is not None: message += ": " + msg assert a > b, message def doctest_skip_parser(func): """ Decorator replaces custom skip test markup in doctests Say a function has a docstring:: >>> something, HAVE_AMODULE, HAVE_BMODULE = 0, False, False >>> something # skip if not HAVE_AMODULE 0 >>> something # skip if HAVE_BMODULE 0 This decorator will evaluate the expression after ``skip if``. If this evaluates to True, then the comment is replaced by ``# doctest: +SKIP``. If False, then the comment is just removed. The expression is evaluated in the ``globals`` scope of `func`. For example, if the module global ``HAVE_AMODULE`` is False, and module global ``HAVE_BMODULE`` is False, the returned function will have docstring:: >>> something # doctest: +SKIP >>> something + else # doctest: +SKIP >>> something # doctest: +SKIP """ lines = func.__doc__.split('\n') new_lines = [] for line in lines: match = SKIP_RE.match(line) if match is None: new_lines.append(line) continue code, space, expr = match.groups() try: # Works as a function decorator if eval(expr, func.__globals__): code = code + space + "# doctest: +SKIP" except AttributeError: # Works as a class decorator if eval(expr, func.__init__.__globals__): code = code + space + "# doctest: +SKIP" new_lines.append(code) func.__doc__ = "\n".join(new_lines) return func def roundtrip(image, plugin, suffix): """Save and read an image using a specified plugin""" if '.' not in suffix: suffix = '.' + suffix temp_file = NamedTemporaryFile(suffix=suffix, delete=False) fname = temp_file.name temp_file.close() io.imsave(fname, image, plugin=plugin) new = io.imread(fname, plugin=plugin) try: os.remove(fname) except Exception: pass return new def color_check(plugin, fmt='png'): """Check roundtrip behavior for color images. All major input types should be handled as ubytes and read back correctly. """ img = img_as_ubyte(data.chelsea()) r1 = roundtrip(img, plugin, fmt) testing.assert_allclose(img, r1) img2 = img > 128 r2 = roundtrip(img2, plugin, fmt) testing.assert_allclose(img2.astype(np.uint8), r2) img3 = img_as_float(img) with expected_warnings(['precision loss']): r3 = roundtrip(img3, plugin, fmt) testing.assert_allclose(r3, img) with expected_warnings(['precision loss']): img4 = img_as_int(img) if fmt.lower() in (('tif', 'tiff')): img4 -= 100 with expected_warnings(['sign loss']): r4 = roundtrip(img4, plugin, fmt) testing.assert_allclose(r4, img4) else: with expected_warnings(['sign loss|precision loss']): r4 = roundtrip(img4, plugin, fmt) testing.assert_allclose(r4, img_as_ubyte(img4)) img5 = img_as_uint(img) with expected_warnings(['precision loss']): r5 = roundtrip(img5, plugin, fmt) testing.assert_allclose(r5, img) def mono_check(plugin, fmt='png'): """Check the roundtrip behavior for images that support most types. All major input types should be handled. """ img = img_as_ubyte(data.moon()) r1 = roundtrip(img, plugin, fmt) testing.assert_allclose(img, r1) img2 = img > 128 r2 = roundtrip(img2, plugin, fmt) testing.assert_allclose(img2.astype(np.uint8), r2) img3 = img_as_float(img) with expected_warnings(['precision|\A\Z']): r3 = roundtrip(img3, plugin, fmt) if r3.dtype.kind == 'f': testing.assert_allclose(img3, r3) else: testing.assert_allclose(r3, img_as_uint(img)) with expected_warnings(['precision loss']): img4 = img_as_int(img) if fmt.lower() in (('tif', 'tiff')): img4 -= 100 with expected_warnings(['sign loss|\A\Z']): r4 = roundtrip(img4, plugin, fmt) testing.assert_allclose(r4, img4) else: with expected_warnings(['precision loss|sign loss']): r4 = roundtrip(img4, plugin, fmt) testing.assert_allclose(r4, img_as_uint(img4)) img5 = img_as_uint(img) r5 = roundtrip(img5, plugin, fmt) testing.assert_allclose(r5, img5) def setup_test(): """Default package level setup routine for skimage tests. Import packages known to raise warnings, and then force warnings to raise errors. Also set the random seed to zero. """ warnings.simplefilter('default') from scipy import signal, ndimage, special, optimize, linalg from scipy.io import loadmat from skimage import viewer np.random.seed(0) warnings.simplefilter('error') def teardown_test(): """Default package level teardown routine for skimage tests. Restore warnings to default behavior """ warnings.simplefilter('default') def test_parallel(num_threads=2): """Decorator to run the same function multiple times in parallel. This decorator is useful to ensure that separate threads execute concurrently and correctly while releasing the GIL. Parameters ---------- num_threads : int, optional The number of times the function is run in parallel. """ assert num_threads > 0 def wrapper(func): @functools.wraps(func) def inner(*args, **kwargs): threads = [] for i in range(num_threads - 1): thread = threading.Thread(target=func, args=args, kwargs=kwargs) threads.append(thread) for thread in threads: thread.start() result = func(*args, **kwargs) for thread in threads: thread.join() return result return inner return wrapper if __name__ == '__main__': color_check('pil') mono_check('pil') mono_check('pil', 'bmp') mono_check('pil', 'tiff')