make Test Outcomes inherit from BaseException instead of exception

fixes #580

_pytest/outcomes.py

@@ -0,0 +1,141 @@
+"""
+exception classes and constants handling test outcomes
+as well as functions creating them
+"""
+from __future__ import absolute_import, division, print_function
+import py
+import sys
+
+
+class OutcomeException(BaseException):
+    """ OutcomeException and its subclass instances indicate and
+        contain info about test and collection outcomes.
+    """
+    def __init__(self, msg=None, pytrace=True):
+        BaseException.__init__(self, msg)
+        self.msg = msg
+        self.pytrace = pytrace
+
+    def __repr__(self):
+        if self.msg:
+            val = self.msg
+            if isinstance(val, bytes):
+                val = py._builtin._totext(val, errors='replace')
+            return val
+        return "<%s instance>" %(self.__class__.__name__,)
+    __str__ = __repr__
+
+
+TEST_OUTCOME = (OutcomeException, Exception)
+
+
+class Skipped(OutcomeException):
+    # XXX hackish: on 3k we fake to live in the builtins
+    # in order to have Skipped exception printing shorter/nicer
+    __module__ = 'builtins'
+
+    def __init__(self, msg=None, pytrace=True, allow_module_level=False):
+        OutcomeException.__init__(self, msg=msg, pytrace=pytrace)
+        self.allow_module_level = allow_module_level
+
+
+class Failed(OutcomeException):
+    """ raised from an explicit call to pytest.fail() """
+    __module__ = 'builtins'
+
+
+class Exit(KeyboardInterrupt):
+    """ raised for immediate program exits (no tracebacks/summaries)"""
+    def __init__(self, msg="unknown reason"):
+        self.msg = msg
+        KeyboardInterrupt.__init__(self, msg)
+
+# exposed helper methods
+
+def exit(msg):
+    """ exit testing process as if KeyboardInterrupt was triggered. """
+    __tracebackhide__ = True
+    raise Exit(msg)
+
+
+exit.Exception = Exit
+
+
+def skip(msg=""):
+    """ skip an executing test with the given message.  Note: it's usually
+    better to use the pytest.mark.skipif marker to declare a test to be
+    skipped under certain conditions like mismatching platforms or
+    dependencies.  See the pytest_skipping plugin for details.
+    """
+    __tracebackhide__ = True
+    raise Skipped(msg=msg)
+
+
+skip.Exception = Skipped
+
+
+def fail(msg="", pytrace=True):
+    """ explicitly fail an currently-executing test with the given Message.
+
+    :arg pytrace: if false the msg represents the full failure information
+                  and no python traceback will be reported.
+    """
+    __tracebackhide__ = True
+    raise Failed(msg=msg, pytrace=pytrace)
+
+
+fail.Exception = Failed
+
+
+
+class XFailed(fail.Exception):
+    """ raised from an explicit call to pytest.xfail() """
+
+
+def xfail(reason=""):
+    """ xfail an executing test or setup functions with the given reason."""
+    __tracebackhide__ = True
+    raise XFailed(reason)
+
+
+xfail.Exception = XFailed
+
+
+
+def importorskip(modname, minversion=None):
+    """ return imported module if it has at least "minversion" as its
+    __version__ attribute.  If no minversion is specified the a skip
+    is only triggered if the module can not be imported.
+    """
+    import warnings
+    __tracebackhide__ = True
+    compile(modname, '', 'eval') # to catch syntaxerrors
+    should_skip = False
+
+    with warnings.catch_warnings():
+        # make sure to ignore ImportWarnings that might happen because
+        # of existing directories with the same name we're trying to
+        # import but without a __init__.py file
+        warnings.simplefilter('ignore')
+        try:
+            __import__(modname)
+        except ImportError:
+            # Do not raise chained exception here(#1485)
+            should_skip = True
+    if should_skip:
+        raise Skipped("could not import %r" %(modname,), allow_module_level=True)
+    mod = sys.modules[modname]
+    if minversion is None:
+        return mod
+    verattr = getattr(mod, '__version__', None)
+    if minversion is not None:
+        try:
+            from pkg_resources import parse_version as pv
+        except ImportError:
+            raise Skipped("we have a required version for %r but can not import "
+                          "pkg_resources to parse version strings." % (modname,),
+                          allow_module_level=True)
+        if verattr is None or pv(verattr) < pv(minversion):
+            raise Skipped("module %r has __version__ %r, required is: %r" %(
+                          modname, verattr, minversion), allow_module_level=True)
+    return mod