Update contrib/python/traitlets/py3 to 5.11.2

1 files changed, 114 insertions, 0 deletions

diff --git a/contrib/python/traitlets/py3/tests/_warnings.py b/contrib/python/traitlets/py3/tests/_warnings.py
new file mode 100644
index 00000000000..e3c3a0ac6d6
--- /dev/null
+++ b/contrib/python/traitlets/py3/tests/_warnings.py
@@ -0,0 +1,114 @@
+# From scikit-image: https://github.com/scikit-image/scikit-image/blob/c2f8c4ab123ebe5f7b827bc495625a32bb225c10/skimage/_shared/_warnings.py
+# Licensed under modified BSD license
+
+__all__ = ["all_warnings", "expected_warnings"]
+
+import inspect
+import os
+import re
+import sys
+import warnings
+from contextlib import contextmanager
+from unittest import mock
+
+
+@contextmanager
+def all_warnings():
+    """
+    Context for use in testing to ensure that all warnings are raised.
+    Examples
+    --------
+    >>> import warnings
+    >>> def foo():
+    ...     warnings.warn(RuntimeWarning("bar"))
+
+    We raise the warning once, while the warning filter is set to "once".
+    Hereafter, the warning is invisible, even with custom filters:
+    >>> with warnings.catch_warnings():
+    ...     warnings.simplefilter('once')
+    ...     foo()
+
+    We can now run ``foo()`` without a warning being raised:
+    >>> from numpy.testing import assert_warns  # doctest: +SKIP
+    >>> foo()  # doctest: +SKIP
+
+    To catch the warning, we call in the help of ``all_warnings``:
+    >>> with all_warnings():  # doctest: +SKIP
+    ...     assert_warns(RuntimeWarning, foo)
+    """
+
+    # Whenever a warning is triggered, Python adds a __warningregistry__
+    # member to the *calling* module.  The exercize here is to find
+    # and eradicate all those breadcrumbs that were left lying around.
+    #
+    # We proceed by first searching all parent calling frames and explicitly
+    # clearing their warning registries (necessary for the doctests above to
+    # pass).  Then, we search for all submodules of skimage and clear theirs
+    # as well (necessary for the skimage test suite to pass).
+
+    frame = inspect.currentframe()
+    if frame:
+        for f in inspect.getouterframes(frame):
+            f[0].f_locals["__warningregistry__"] = {}
+    del frame
+
+    for _, mod in list(sys.modules.items()):
+        try:
+            mod.__warningregistry__.clear()
+        except AttributeError:
+            pass
+
+    with warnings.catch_warnings(record=True) as w, mock.patch.dict(
+        os.environ, {"TRAITLETS_ALL_DEPRECATIONS": "1"}
+    ):
+        warnings.simplefilter("always")
+        yield w
+
+
+@contextmanager
+def expected_warnings(matching):
+    r"""Context for use in testing to catch known warnings matching regexes
+
+    Parameters
+    ----------
+    matching : list of strings or compiled regexes
+        Regexes for the desired warning to catch
+
+    Examples
+    --------
+    >>> from skimage import data, img_as_ubyte, img_as_float  # doctest: +SKIP
+    >>> with expected_warnings(["precision loss"]):           # doctest: +SKIP
+    ...     d = img_as_ubyte(img_as_float(data.coins()))      # doctest: +SKIP
+
+    Notes
+    -----
+    Uses `all_warnings` to ensure all warnings are raised.
+    Upon exiting, it checks the recorded warnings for the desired matching
+    pattern(s).
+    Raises a ValueError if any match was not found or an unexpected
+    warning was raised.
+    Allows for three types of behaviors: "and", "or", and "optional" matches.
+    This is done to accomodate different build enviroments or loop conditions
+    that may produce different warnings.  The behaviors can be combined.
+    If you pass multiple patterns, you get an orderless "and", where all of the
+    warnings must be raised.
+    If you use the "|" operator in a pattern, you can catch one of several warnings.
+    Finally, you can use "|\A\Z" in a pattern to signify it as optional.
+    """
+    with all_warnings() as w:
+        # enter context
+        yield w
+        # exited user context, check the recorded warnings
+        remaining = [m for m in matching if r"\A\Z" not in m.split("|")]
+        for warn in w:
+            found = False
+            for match in matching:
+                if re.search(match, str(warn.message)) is not None:
+                    found = True
+                    if match in remaining:
+                        remaining.remove(match)
+            if not found:
+                raise ValueError("Unexpected warning: %s" % str(warn.message))
+        if len(remaining) > 0:
+            msg = "No warning raised matching:\n%s" % "\n".join(remaining)
+            raise ValueError(msg)