Files
MLPproject/.venv/lib/python3.12/site-packages/skimage/_shared/testing.py
2025-10-23 15:44:32 +02:00

312 lines
9.2 KiB
Python

"""
Testing utilities.
"""
import os
import platform
import re
import struct
import sys
import functools
import inspect
from tempfile import NamedTemporaryFile
import numpy as np
from numpy import testing
from numpy.testing import (
TestCase,
assert_,
assert_warns,
assert_no_warnings,
assert_equal,
assert_almost_equal,
assert_array_equal,
assert_allclose,
assert_array_almost_equal,
assert_array_almost_equal_nulp,
assert_array_less,
)
from .. import data, io
from ..data._fetchers import _fetch
from ..util import img_as_uint, img_as_float, img_as_int, img_as_ubyte
from ._warnings import expected_warnings
from ._dependency_checks import is_wasm
import pytest
skipif = pytest.mark.skipif
xfail = pytest.mark.xfail
parametrize = pytest.mark.parametrize
raises = pytest.raises
fixture = pytest.fixture
SKIP_RE = re.compile(r"(\s*>>>.*?)(\s*)#\s*skip\s+if\s+(.*)$")
# true if python is running in 32bit mode
# Calculate the size of a void * pointer in bits
# https://docs.python.org/3/library/struct.html
arch32 = struct.calcsize("P") * 8 == 32
def assert_less(a, b, msg=None):
message = f"{a!r} is not lower than {b!r}"
if msg is not None:
message += ": " + msg
assert a < b, message
def assert_greater(a, b, msg=None):
message = f"{a!r} is not greater than {b!r}"
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
with NamedTemporaryFile(suffix=suffix, delete=False) as temp_file:
fname = temp_file.name
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, r2.astype(bool))
img3 = img_as_float(img)
r3 = roundtrip(img3, plugin, fmt)
testing.assert_allclose(r3, img)
img4 = img_as_int(img)
if fmt.lower() in (('tif', 'tiff')):
img4 -= 100
r4 = roundtrip(img4, plugin, fmt)
testing.assert_allclose(r4, img4)
else:
r4 = roundtrip(img4, plugin, fmt)
testing.assert_allclose(r4, img_as_ubyte(img4))
img5 = img_as_uint(img)
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, r2.astype(bool))
img3 = img_as_float(img)
r3 = roundtrip(img3, plugin, fmt)
if r3.dtype.kind == 'f':
testing.assert_allclose(img3, r3)
else:
testing.assert_allclose(r3, img_as_uint(img))
img4 = img_as_int(img)
if fmt.lower() in (('tif', 'tiff')):
img4 -= 100
r4 = roundtrip(img4, plugin, fmt)
testing.assert_allclose(r4, img4)
else:
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 fetch(data_filename):
"""Attempt to fetch data, but if unavailable, skip the tests."""
try:
return _fetch(data_filename)
except (ConnectionError, ModuleNotFoundError):
pytest.skip(f'Unable to download {data_filename}', allow_module_level=True)
# Ref: about the lack of threading support in WASM, please see
# https://github.com/pyodide/pyodide/issues/237
def run_in_parallel(num_threads=2, warnings_matching=None):
"""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.
It is currently skipped when running on WASM-based platforms, as
the threading module is not supported.
Parameters
----------
num_threads : int, optional
The number of times the function is run in parallel.
warnings_matching: list or None
This parameter is passed on to `expected_warnings` so as not to have
race conditions with the warnings filters. A single
`expected_warnings` context manager is used for all threads.
If None, then no warnings are checked.
"""
assert num_threads > 0
def wrapper(func):
if is_wasm:
# Threading isn't supported on WASM, return early
return func
import threading
@functools.wraps(func)
def inner(*args, **kwargs):
with expected_warnings(warnings_matching):
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()
func(*args, **kwargs)
for thread in threads:
thread.join()
return inner
return wrapper
def assert_stacklevel(warnings, *, offset=-1):
"""Assert correct stacklevel of captured warnings.
When scikit-image raises warnings, the stacklevel should ideally be set
so that the origin of the warnings will point to the public function
that was called by the user and not necessarily the very place where the
warnings were emitted (which may be inside some internal function).
This utility function helps with checking that
the stacklevel was set correctly on warnings captured by `pytest.warns`.
Parameters
----------
warnings : collections.abc.Iterable[warning.WarningMessage]
Warnings that were captured by `pytest.warns`.
offset : int, optional
Offset from the line this function is called to the line were the
warning is supposed to originate from. For multiline calls, the
first line is relevant. Defaults to -1 which corresponds to the line
right above the one where this function is called.
Raises
------
AssertionError
If a warning in `warnings` does not match the expected line number or
file name.
Examples
--------
>>> def test_something():
... with pytest.warns(UserWarning, match="some message") as record:
... something_raising_a_warning()
... assert_stacklevel(record)
...
>>> def test_another_thing():
... with pytest.warns(UserWarning, match="some message") as record:
... iam_raising_many_warnings(
... "A long argument that forces the call to wrap."
... )
... assert_stacklevel(record, offset=-3)
"""
__tracebackhide__ = True # Hide traceback for py.test
frame = inspect.stack()[1].frame # 0 is current frame, 1 is outer frame
line_number = frame.f_lineno + offset
filename = frame.f_code.co_filename
expected = f"{filename}:{line_number}"
for warning in warnings:
actual = f"{warning.filename}:{warning.lineno}"
msg = (
"Warning with wrong stacklevel:\n"
f" Expected: {expected}\n"
f" Actual: {actual}\n"
f" {warning.category.__name__}: {warning.message}"
)
assert actual == expected, msg