Update numpy's decorators.py from upstream.

IPython/external/decorators.py

@@ -1,90 +1,275 b''
-"""Decorators for labeling test objects
+"""
+Decorators for labeling and modifying behavior of test objects.
 
 Decorators that merely return a modified version of the original
-function object are straightforward.  Decorators that return a new
+function object are straightforward. Decorators that return a new
 function object need to use
-nose.tools.make_decorator(original_function)(decorator) in returning
-the decorator, in order to preserve metadata such as function name,
-setup and teardown functions and so on - see nose.tools for more
-information.
+::
+
+  nose.tools.make_decorator(original_function)(decorator)
+
+in returning the decorator, in order to preserve meta-data such as
+function name, setup and teardown functions and so on - see
+``nose.tools`` for more information.
 
 """
+import warnings
+import sys
+
+from numpy.testing.utils import \
+        WarningManager, WarningMessage
 
 def slow(t):
-    """Labels a test as 'slow'.
+    """
+    Label a test as 'slow'.
 
     The exact definition of a slow test is obviously both subjective and
     hardware-dependent, but in general any individual test that requires more
     than a second or two should be labeled as slow (the whole suite consits of
-    thousands of tests, so even a second is significant)."""
+    thousands of tests, so even a second is significant).
+
+    Parameters
+    ----------
+    t : callable
+        The test to label as slow.
+
+    Returns
+    -------
+    t : callable
+        The decorated test `t`.
+
+    Examples
+    --------
+    The `numpy.testing` module includes ``import decorators as dec``.
+    A test can be decorated as slow like this::
+
+      from numpy.testing import *
+
+      @dec.slow
+      def test_big(self):
+          print 'Big, slow test'
+
+    """
 
     t.slow = True
     return t
 
 def setastest(tf=True):
-    ''' Signals to nose that this function is or is not a test
+    """
+    Signals to nose that this function is or is not a test.
 
     Parameters
     ----------
     tf : bool
-        If True specifies this is a test, not a test otherwise
+        If True, specifies that the decorated callable is a test.
+        If False, specifies that the decorated callable is not a test.
+        Default is True.
+
+    Notes
+    -----
+    This decorator can't use the nose namespace, because it can be
+    called from a non-test module. See also ``istest`` and ``nottest`` in
+    ``nose.tools``.
 
-    This decorator cannot use the nose namespace, because it can be
-    called from a non-test module. See also istest and nottest in
-    nose.tools
+    Examples
+    --------
+    `setastest` can be used in the following way::
 
-    '''
+      from numpy.testing.decorators import setastest
+
+      @setastest(False)
+      def func_with_test_in_name(arg1, arg2):
+          pass
+
+    """
     def set_test(t):
         t.__test__ = tf
         return t
     return set_test
 
-def skipif(skip_condition=True, msg=None):
-    ''' Make function raise SkipTest exception if skip_condition is true
+def skipif(skip_condition, msg=None):
+    """
+    Make function raise SkipTest exception if a given condition is true.
+
+    If the condition is a callable, it is used at runtime to dynamically
+    make the decision. This is useful for tests that may require costly
+    imports, to delay the cost until the test suite is actually executed.
 
     Parameters
     ----------
-    skip_condition : bool or callable. 
-        Flag to determine whether to skip test.  If the condition is a 
-        callable, it is used at runtime to dynamically make the decision.  This 
-        is useful for tests that may require costly imports, to delay the cost 
-        until the test suite is actually executed.        
-    msg : string
-        Message to give on raising a SkipTest exception
-
-   Returns
-   -------
-   decorator : function
-       Decorator, which, when applied to a function, causes SkipTest
-       to be raised when the skip_condition was True, and the function
-       to be called normally otherwise.
+    skip_condition : bool or callable
+        Flag to determine whether to skip the decorated test.
+    msg : str, optional
+        Message to give on raising a SkipTest exception. Default is None.
+
+    Returns
+    -------
+    decorator : function
+        Decorator which, when applied to a function, causes SkipTest
+        to be raised when `skip_condition` is True, and the function
+        to be called normally otherwise.
 
     Notes
     -----
-    You will see from the code that we had to further decorate the
-    decorator with the nose.tools.make_decorator function in order to
-    transmit function name, and various other metadata.
-    '''
-    if msg is None:
-        msg = 'Test skipped due to test condition'
+    The decorator itself is decorated with the ``nose.tools.make_decorator``
+    function in order to transmit function name, and various other metadata.
+
+    """
+
     def skip_decorator(f):
-        # Local import to avoid a hard nose dependency and only incur the 
-        # import time overhead at actual test-time. 
+        # Local import to avoid a hard nose dependency and only incur the
+        # import time overhead at actual test-time.
         import nose
-        def skipper(*args, **kwargs):
-            if skip_condition:
-                raise nose.SkipTest, msg
+
+        # Allow for both boolean or callable skip conditions.
+        if callable(skip_condition):
+            skip_val = lambda : skip_condition()
+        else:
+            skip_val = lambda : skip_condition
+
+        def get_msg(func,msg=None):
+            """Skip message with information about function being skipped."""
+            if msg is None: 
+                out = 'Test skipped due to test condition'
+            else: 
+                out = '\n'+msg
+
+            return "Skipping test: %s%s" % (func.__name__,out)
+
+        # We need to define *two* skippers because Python doesn't allow both
+        # return with value and yield inside the same function.
+        def skipper_func(*args, **kwargs):
+            """Skipper for normal test functions."""
+            if skip_val():
+                raise nose.SkipTest(get_msg(f,msg))
             else:
                 return f(*args, **kwargs)
+
+        def skipper_gen(*args, **kwargs):
+            """Skipper for test generators."""
+            if skip_val():
+                raise nose.SkipTest(get_msg(f,msg))
+            else:
+                for x in f(*args, **kwargs):
+                    yield x
+
+        # Choose the right skipper to use when building the actual decorator.
+        if nose.util.isgenerator(f):
+            skipper = skipper_gen
+        else:
+            skipper = skipper_func
+            
         return nose.tools.make_decorator(f)(skipper)
+
     return skip_decorator
 
-def skipknownfailure(f):
-    ''' Decorator to raise SkipTest for test known to fail
-    '''
-    # Local import to avoid a hard nose dependency and only incur the 
-    # import time overhead at actual test-time. 
-    import nose
-    def skipper(*args, **kwargs):
-        raise nose.SkipTest, 'This test is known to fail'
-    return nose.tools.make_decorator(f)(skipper)
+
+def knownfailureif(fail_condition, msg=None):
+    """
+    Make function raise KnownFailureTest exception if given condition is true.
+
+    If the condition is a callable, it is used at runtime to dynamically
+    make the decision. This is useful for tests that may require costly
+    imports, to delay the cost until the test suite is actually executed.
+
+    Parameters
+    ----------
+    fail_condition : bool or callable
+        Flag to determine whether to mark the decorated test as a known
+        failure (if True) or not (if False).
+    msg : str, optional
+        Message to give on raising a KnownFailureTest exception.
+        Default is None.
+
+    Returns
+    -------
+    decorator : function
+        Decorator, which, when applied to a function, causes SkipTest
+        to be raised when `skip_condition` is True, and the function
+        to be called normally otherwise.
+
+    Notes
+    -----
+    The decorator itself is decorated with the ``nose.tools.make_decorator``
+    function in order to transmit function name, and various other metadata.
+
+    """
+    if msg is None:
+        msg = 'Test skipped due to known failure'
+
+    # Allow for both boolean or callable known failure conditions.
+    if callable(fail_condition):
+        fail_val = lambda : fail_condition()
+    else:
+        fail_val = lambda : fail_condition
+
+    def knownfail_decorator(f):
+        # Local import to avoid a hard nose dependency and only incur the
+        # import time overhead at actual test-time.
+        import nose
+        from noseclasses import KnownFailureTest
+        def knownfailer(*args, **kwargs):
+            if fail_val():
+                raise KnownFailureTest, msg
+            else:
+                return f(*args, **kwargs)
+        return nose.tools.make_decorator(f)(knownfailer)
+
+    return knownfail_decorator
+
+def deprecated(conditional=True):
+    """
+    Filter deprecation warnings while running the test suite.
+
+    This decorator can be used to filter DeprecationWarning's, to avoid
+    printing them during the test suite run, while checking that the test
+    actually raises a DeprecationWarning.
+
+    Parameters
+    ----------
+    conditional : bool or callable, optional
+        Flag to determine whether to mark test as deprecated or not. If the
+        condition is a callable, it is used at runtime to dynamically make the
+        decision. Default is True.
+
+    Returns
+    -------
+    decorator : function
+        The `deprecated` decorator itself.
+
+    Notes
+    -----
+    .. versionadded:: 1.4.0
+
+    """
+    def deprecate_decorator(f):
+        # Local import to avoid a hard nose dependency and only incur the
+        # import time overhead at actual test-time.
+        import nose
+        from noseclasses import KnownFailureTest
+
+        def _deprecated_imp(*args, **kwargs):
+            # Poor man's replacement for the with statement
+            ctx = WarningManager(record=True)
+            l = ctx.__enter__()
+            warnings.simplefilter('always')
+            try:
+                f(*args, **kwargs)
+                if not len(l) > 0:
+                    raise AssertionError("No warning raised when calling %s"
+                            % f.__name__)
+                if not l[0].category is DeprecationWarning:
+                    raise AssertionError("First warning for %s is not a " \
+                            "DeprecationWarning( is %s)" % (f.__name__, l[0]))
+            finally:
+                ctx.__exit__()
+
+        if callable(conditional):
+            cond = conditional()
+        else:
+            cond = conditional
+        if cond:
+            return nose.tools.make_decorator(f)(_deprecated_imp)
+        else:
+            return f
+    return deprecate_decorator