remove a few more obsolete twisted notes

IPython/testing/iptest.py

@@ -1,523 +1,520 b''
 # -*- coding: utf-8 -*-
 """IPython Test Suite Runner.
 
 This module provides a main entry point to a user script to test IPython
 itself from the command line. There are two ways of running this script:
 
 1. With the syntax `iptest all`.  This runs our entire test suite by
    calling this script (with different arguments) recursively.  This
    causes modules and package to be tested in different processes, using nose
    or trial where appropriate.
 2. With the regular nose syntax, like `iptest -vvs IPython`.  In this form
    the script simply calls nose, but with special command line flags and
    plugins loaded.
 
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2009-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Stdlib
 import os
 import os.path as path
 import signal
 import sys
 import subprocess
 import tempfile
 import time
 import warnings
 
 # Note: monkeypatch!
 # We need to monkeypatch a small problem in nose itself first, before importing
 # it for actual use.  This should get into nose upstream, but its release cycle
 # is slow and we need it for our parametric tests to work correctly.
 from IPython.testing import nosepatch
 # Now, proceed to import nose itself
 import nose.plugins.builtin
 from nose.plugins.xunit import Xunit
 from nose import SkipTest
 from nose.core import TestProgram
 
 # Our own imports
 from IPython.utils.importstring import import_item
 from IPython.utils.path import get_ipython_module_path
 from IPython.utils.process import find_cmd, pycmd2argv
 from IPython.utils.sysinfo import sys_info
 
 from IPython.testing import globalipapp
 from IPython.testing.plugin.ipdoctest import IPythonDoctest
 from IPython.external.decorators import KnownFailure, knownfailureif
 
 pjoin = path.join
 
 
 #-----------------------------------------------------------------------------
 # Globals
 #-----------------------------------------------------------------------------
 
 
 #-----------------------------------------------------------------------------
 # Warnings control
 #-----------------------------------------------------------------------------
 
 # Twisted generates annoying warnings with Python 2.6, as will do other code
 # that imports 'sets' as of today
 warnings.filterwarnings('ignore', 'the sets module is deprecated',
                         DeprecationWarning )
 
 # This one also comes from Twisted
 warnings.filterwarnings('ignore', 'the sha module is deprecated',
                         DeprecationWarning)
 
 # Wx on Fedora11 spits these out
 warnings.filterwarnings('ignore', 'wxPython/wxWidgets release number mismatch',
                         UserWarning)
 
 # ------------------------------------------------------------------------------
 # Monkeypatch Xunit to count known failures as skipped.
 # ------------------------------------------------------------------------------
 def monkeypatch_xunit():
     try:
         knownfailureif(True)(lambda: None)()
     except Exception as e:
         KnownFailureTest = type(e)
 
     def addError(self, test, err, capt=None):
         if issubclass(err[0], KnownFailureTest):
             err = (SkipTest,) + err[1:]
         return self.orig_addError(test, err, capt)
 
     Xunit.orig_addError = Xunit.addError
     Xunit.addError = addError
 
 #-----------------------------------------------------------------------------
 # Logic for skipping doctests
 #-----------------------------------------------------------------------------
 def extract_version(mod):
     return mod.__version__
 
 def test_for(item, min_version=None, callback=extract_version):
     """Test to see if item is importable, and optionally check against a minimum
     version.
 
     If min_version is given, the default behavior is to check against the
     `__version__` attribute of the item, but specifying `callback` allows you to
     extract the value you are interested in. e.g::
 
         In [1]: import sys
 
         In [2]: from IPython.testing.iptest import test_for
 
         In [3]: test_for('sys', (2,6), callback=lambda sys: sys.version_info)
         Out[3]: True
 
     """
     try:
         check = import_item(item)
     except (ImportError, RuntimeError):
         # GTK reports Runtime error if it can't be initialized even if it's
         # importable.
         return False
     else:
         if min_version:
             if callback:
                 # extra processing step to get version to compare
                 check = callback(check)
 
             return check >= min_version
         else:
             return True
 
 # Global dict where we can store information on what we have and what we don't
 # have available at test run time
 have = {}
 
 have['curses'] = test_for('_curses')
 have['matplotlib'] = test_for('matplotlib')
 have['pexpect'] = test_for('IPython.external.pexpect')
 have['pymongo'] = test_for('pymongo')
 have['wx'] = test_for('wx')
 have['wx.aui'] = test_for('wx.aui')
 have['qt'] = test_for('IPython.external.qt')
 have['sqlite3'] = test_for('sqlite3')
 
 have['tornado'] = test_for('tornado.version_info', (2,1,0), callback=None)
 
 if os.name == 'nt':
     min_zmq = (2,1,7)
 else:
     min_zmq = (2,1,4)
 
 def version_tuple(mod):
     "turn '2.1.9' into (2,1,9), and '2.1dev' into (2,1,999)"
     # turn 'dev' into 999, because Python3 rejects str-int comparisons
     vs = mod.__version__.replace('dev', '.999')
     tup = tuple([int(v) for v in vs.split('.') ])
     return tup
 
 have['zmq'] = test_for('zmq', min_zmq, version_tuple)
 
 #-----------------------------------------------------------------------------
 # Functions and classes
 #-----------------------------------------------------------------------------
 
 def report():
     """Return a string with a summary report of test-related variables."""
 
     out = [ sys_info(), '\n']
 
     avail = []
     not_avail = []
 
     for k, is_avail in have.items():
         if is_avail:
             avail.append(k)
         else:
             not_avail.append(k)
 
     if avail:
         out.append('\nTools and libraries available at test time:\n')
         avail.sort()
         out.append('   ' + ' '.join(avail)+'\n')
 
     if not_avail:
         out.append('\nTools and libraries NOT available at test time:\n')
         not_avail.sort()
         out.append('   ' + ' '.join(not_avail)+'\n')
 
     return ''.join(out)
 
 
 def make_exclude():
     """Make patterns of modules and packages to exclude from testing.
 
     For the IPythonDoctest plugin, we need to exclude certain patterns that
     cause testing problems.  We should strive to minimize the number of
     skipped modules, since this means untested code.
 
     These modules and packages will NOT get scanned by nose at all for tests.
     """
     # Simple utility to make IPython paths more readably, we need a lot of
     # these below
     ipjoin = lambda *paths: pjoin('IPython', *paths)
 
     exclusions = [ipjoin('external'),
                   pjoin('IPython_doctest_plugin'),
                   ipjoin('quarantine'),
                   ipjoin('deathrow'),
                   ipjoin('testing', 'attic'),
                   # This guy is probably attic material
                   ipjoin('testing', 'mkdoctests'),
                   # Testing inputhook will need a lot of thought, to figure out
                   # how to have tests that don't lock up with the gui event
                   # loops in the picture
                   ipjoin('lib', 'inputhook'),
                   # Config files aren't really importable stand-alone
                   ipjoin('config', 'default'),
                   ipjoin('config', 'profile'),
                   ]
     if not have['sqlite3']:
         exclusions.append(ipjoin('core', 'tests', 'test_history'))
         exclusions.append(ipjoin('core', 'history'))
     if not have['wx']:
         exclusions.append(ipjoin('lib', 'inputhookwx'))
 
     # We do this unconditionally, so that the test suite doesn't import
     # gtk, changing the default encoding and masking some unicode bugs.
     exclusions.append(ipjoin('lib', 'inputhookgtk'))
 
     # These have to be skipped on win32 because the use echo, rm, cd, etc.
     # See ticket https://github.com/ipython/ipython/issues/87
     if sys.platform == 'win32':
         exclusions.append(ipjoin('testing', 'plugin', 'test_exampleip'))
         exclusions.append(ipjoin('testing', 'plugin', 'dtexample'))
 
     if not have['pexpect']:
         exclusions.extend([ipjoin('scripts', 'irunner'),
                            ipjoin('lib', 'irunner'),
                            ipjoin('lib', 'tests', 'test_irunner'),
                            ipjoin('frontend', 'terminal', 'console'),
                            ])
 
     if not have['zmq']:
         exclusions.append(ipjoin('zmq'))
         exclusions.append(ipjoin('frontend', 'qt'))
         exclusions.append(ipjoin('frontend', 'html'))
         exclusions.append(ipjoin('frontend', 'consoleapp.py'))
         exclusions.append(ipjoin('frontend', 'terminal', 'console'))
         exclusions.append(ipjoin('parallel'))
     elif not have['qt']:
         exclusions.append(ipjoin('frontend', 'qt'))
 
     if not have['pymongo']:
         exclusions.append(ipjoin('parallel', 'controller', 'mongodb'))
         exclusions.append(ipjoin('parallel', 'tests', 'test_mongodb'))
 
     if not have['matplotlib']:
         exclusions.extend([ipjoin('core', 'pylabtools'),
                            ipjoin('core', 'tests', 'test_pylabtools')])
 
     if not have['tornado']:
         exclusions.append(ipjoin('frontend', 'html'))
 
     # This is needed for the reg-exp to match on win32 in the ipdoctest plugin.
     if sys.platform == 'win32':
         exclusions = [s.replace('\\','\\\\') for s in exclusions]
 
     return exclusions
 
 
 class IPTester(object):
     """Call that calls iptest or trial in a subprocess.
     """
     #: string, name of test runner that will be called
     runner = None
     #: list, parameters for test runner
     params = None
     #: list, arguments of system call to be made to call test runner
     call_args = None
     #: list, process ids of subprocesses we start (for cleanup)
     pids = None
     #: str, coverage xml output file
     coverage_xml = None
 
     def __init__(self, runner='iptest', params=None):
         """Create new test runner."""
         p = os.path
         if runner == 'iptest':
             iptest_app = get_ipython_module_path('IPython.testing.iptest')
             self.runner = pycmd2argv(iptest_app) + sys.argv[1:]
         else:
             raise Exception('Not a valid test runner: %s' % repr(runner))
         if params is None:
             params = []
         if isinstance(params, str):
             params = [params]
         self.params = params
 
         # Assemble call
         self.call_args = self.runner+self.params
         
         # Find the section we're testing (IPython.foo)
         for sect in self.params:
             if sect.startswith('IPython'): break
         else:
             raise ValueError("Section not found", self.params)
         
         if '--with-xunit' in self.call_args:
             self.call_args.append('--xunit-file=%s' % path.abspath(sect+'.xunit.xml'))
         
         if '--with-xml-coverage' in self.call_args:
             self.coverage_xml = path.abspath(sect+".coverage.xml")
             self.call_args.remove('--with-xml-coverage')
             self.call_args = ["coverage", "run", "--source="+sect] + self.call_args[1:]
 
         # Store pids of anything we start to clean up on deletion, if possible
         # (on posix only, since win32 has no os.kill)
         self.pids = []
 
     if sys.platform == 'win32':
         def _run_cmd(self):
             # On Windows, use os.system instead of subprocess.call, because I
             # was having problems with subprocess and I just don't know enough
             # about win32 to debug this reliably.  Os.system may be the 'old
             # fashioned' way to do it, but it works just fine.  If someone
             # later can clean this up that's fine, as long as the tests run
             # reliably in win32.
             # What types of problems are you having. They may be related to
             # running Python in unboffered mode. BG.
             return os.system(' '.join(self.call_args))
     else:
         def _run_cmd(self):
             # print >> sys.stderr, '*** CMD:', ' '.join(self.call_args) # dbg
             subp = subprocess.Popen(self.call_args)
             self.pids.append(subp.pid)
             # If this fails, the pid will be left in self.pids and cleaned up
             # later, but if the wait call succeeds, then we can clear the
             # stored pid.
             retcode = subp.wait()
             self.pids.pop()
             return retcode
 
     def run(self):
         """Run the stored commands"""
         try:
             retcode = self._run_cmd()
         except:
             import traceback
             traceback.print_exc()
             return 1  # signal failure
         
         if self.coverage_xml:
             subprocess.call(["coverage", "xml", "-o", self.coverage_xml])
         return retcode
 
     def __del__(self):
         """Cleanup on exit by killing any leftover processes."""
 
         if not hasattr(os, 'kill'):
             return
 
         for pid in self.pids:
             try:
                 print 'Cleaning stale PID:', pid
                 os.kill(pid, signal.SIGKILL)
             except OSError:
                 # This is just a best effort, if we fail or the process was
                 # really gone, ignore it.
                 pass
 
 
 def make_runners():
     """Define the top-level packages that need to be tested.
     """
 
     # Packages to be tested via nose, that only depend on the stdlib
     nose_pkg_names = ['config', 'core', 'extensions', 'frontend', 'lib',
                      'scripts', 'testing', 'utils', 'nbformat' ]
 
     if have['zmq']:
         nose_pkg_names.append('parallel')
 
     # For debugging this code, only load quick stuff
     #nose_pkg_names = ['core', 'extensions']  # dbg
 
     # Make fully qualified package names prepending 'IPython.' to our name lists
     nose_packages = ['IPython.%s' % m for m in nose_pkg_names ]
 
     # Make runners
     runners = [ (v, IPTester('iptest', params=v)) for v in nose_packages ]
 
     return runners
 
 
 def run_iptest():
     """Run the IPython test suite using nose.
 
     This function is called when this script is **not** called with the form
     `iptest all`.  It simply calls nose with appropriate command line flags
     and accepts all of the standard nose arguments.
     """
     # Apply our monkeypatch to Xunit
     if '--with-xunit' in sys.argv and not hasattr(Xunit, 'orig_addError'):
         monkeypatch_xunit()
 
     warnings.filterwarnings('ignore',
         'This will be removed soon.  Use IPython.testing.util instead')
 
     argv = sys.argv + [ '--detailed-errors',  # extra info in tracebacks
 
-                        # Loading ipdoctest causes problems with Twisted, but
-                        # our test suite runner now separates things and runs
-                        # all Twisted tests with trial.
                         '--with-ipdoctest',
                         '--ipdoctest-tests','--ipdoctest-extension=txt',
 
                         # We add --exe because of setuptools' imbecility (it
                         # blindly does chmod +x on ALL files).  Nose does the
                         # right thing and it tries to avoid executables,
                         # setuptools unfortunately forces our hand here.  This
                         # has been discussed on the distutils list and the
                         # setuptools devs refuse to fix this problem!
                         '--exe',
                         ]
 
     if nose.__version__ >= '0.11':
         # I don't fully understand why we need this one, but depending on what
         # directory the test suite is run from, if we don't give it, 0 tests
         # get run.  Specifically, if the test suite is run from the source dir
         # with an argument (like 'iptest.py IPython.core', 0 tests are run,
         # even if the same call done in this directory works fine).  It appears
         # that if the requested package is in the current dir, nose bails early
         # by default.  Since it's otherwise harmless, leave it in by default
         # for nose >= 0.11, though unfortunately nose 0.10 doesn't support it.
         argv.append('--traverse-namespace')
 
     # use our plugin for doctesting.  It will remove the standard doctest plugin
     # if it finds it enabled
     plugins = [IPythonDoctest(make_exclude()), KnownFailure()]
     # We need a global ipython running in this process
     globalipapp.start_ipython()
     # Now nose can run
     TestProgram(argv=argv, addplugins=plugins)
 
 
 def run_iptestall():
     """Run the entire IPython test suite by calling nose and trial.
 
     This function constructs :class:`IPTester` instances for all IPython
     modules and package and then runs each of them.  This causes the modules
     and packages of IPython to be tested each in their own subprocess using
-    nose or twisted.trial appropriately.
+    nose.
     """
 
     runners = make_runners()
 
     # Run the test runners in a temporary dir so we can nuke it when finished
     # to clean up any junk files left over by accident.  This also makes it
     # robust against being run in non-writeable directories by mistake, as the
     # temp dir will always be user-writeable.
     curdir = os.getcwdu()
     testdir = tempfile.gettempdir()
     os.chdir(testdir)
 
     # Run all test runners, tracking execution time
     failed = []
     t_start = time.time()
     try:
         for (name, runner) in runners:
             print '*'*70
             print 'IPython test group:',name
             res = runner.run()
             if res:
                 failed.append( (name, runner) )
     finally:
         os.chdir(curdir)
     t_end = time.time()
     t_tests = t_end - t_start
     nrunners = len(runners)
     nfail = len(failed)
     # summarize results
     print
     print '*'*70
     print 'Test suite completed for system with the following information:'
     print report()
     print 'Ran %s test groups in %.3fs' % (nrunners, t_tests)
     print
     print 'Status:'
     if not failed:
         print 'OK'
     else:
         # If anything went wrong, point out what command to rerun manually to
         # see the actual errors and individual summary
         print 'ERROR - %s out of %s test groups failed.' % (nfail, nrunners)
         for name, failed_runner in failed:
             print '-'*40
             print 'Runner failed:',name
             print 'You may wish to rerun this one individually, with:'
             print ' '.join(failed_runner.call_args)
             print
         # Ensure that our exit code indicates failure
         sys.exit(1)
 
 
 def main():
     for arg in sys.argv[1:]:
         if arg.startswith('IPython'):
             # This is in-process
             run_iptest()
     else:
         # This starts subprocesses
         run_iptestall()
 
 
 if __name__ == '__main__':
     main()

IPython/testing/tools.py

@@ -1,396 +1,391 b''
-"""Generic testing tools that do NOT depend on Twisted.
+"""Generic testing tools.
 
 In particular, this module exposes a set of top-level assert* functions that
 can be used in place of nose.tools.assert* in method generators (the ones in
 nose can not, at least as of nose 0.10.4).
 
-Note: our testing package contains testing.util, which does depend on Twisted
-and provides utilities for tests that manage Deferreds.  All testing support
-tools that only depend on nose, IPython or the standard library should go here
-instead.
-
 
 Authors
 -------
 - Fernando Perez <[e-mail]>
 """
 
 from __future__ import absolute_import
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2009-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import os
 import re
 import sys
 import tempfile
 
 from contextlib import contextmanager
 from io import StringIO
 
 try:
     # These tools are used by parts of the runtime, so we make the nose
     # dependency optional at this point.  Nose is a hard dependency to run the
     # test suite, but NOT to use ipython itself.
     import nose.tools as nt
     has_nose = True
 except ImportError:
     has_nose = False
 
 from IPython.config.loader import Config
 from IPython.utils.process import find_cmd, getoutputerror
 from IPython.utils.text import list_strings, getdefaultencoding
 from IPython.utils.io import temp_pyfile, Tee
 from IPython.utils import py3compat
 
 from . import decorators as dec
 from . import skipdoctest
 
 #-----------------------------------------------------------------------------
 # Globals
 #-----------------------------------------------------------------------------
 
 # Make a bunch of nose.tools assert wrappers that can be used in test
 # generators.  This will expose an assert* function for each one in nose.tools.
 
 _tpl = """
 def %(name)s(*a,**kw):
     return nt.%(name)s(*a,**kw)
 """
 
 if has_nose:
     for _x in [a for a in dir(nt) if a.startswith('assert')]:
         exec _tpl % dict(name=_x)
 
 #-----------------------------------------------------------------------------
 # Functions and classes
 #-----------------------------------------------------------------------------
 
 # The docstring for full_path doctests differently on win32 (different path
 # separator) so just skip the doctest there.  The example remains informative.
 doctest_deco = skipdoctest.skip_doctest if sys.platform == 'win32' else dec.null_deco
 
 @doctest_deco
 def full_path(startPath,files):
     """Make full paths for all the listed files, based on startPath.
 
     Only the base part of startPath is kept, since this routine is typically
     used with a script's __file__ variable as startPath.  The base of startPath
     is then prepended to all the listed files, forming the output list.
 
     Parameters
     ----------
       startPath : string
         Initial path to use as the base for the results.  This path is split
       using os.path.split() and only its first component is kept.
 
       files : string or list
         One or more files.
 
     Examples
     --------
 
     >>> full_path('/foo/bar.py',['a.txt','b.txt'])
     ['/foo/a.txt', '/foo/b.txt']
 
     >>> full_path('/foo',['a.txt','b.txt'])
     ['/a.txt', '/b.txt']
 
     If a single file is given, the output is still a list:
     >>> full_path('/foo','a.txt')
     ['/a.txt']
     """
 
     files = list_strings(files)
     base = os.path.split(startPath)[0]
     return [ os.path.join(base,f) for f in files ]
 
 
 def parse_test_output(txt):
     """Parse the output of a test run and return errors, failures.
 
     Parameters
     ----------
     txt : str
       Text output of a test run, assumed to contain a line of one of the
       following forms::
         'FAILED (errors=1)'
         'FAILED (failures=1)'
         'FAILED (errors=1, failures=1)'
 
     Returns
     -------
     nerr, nfail: number of errors and failures.
     """
 
     err_m = re.search(r'^FAILED \(errors=(\d+)\)', txt, re.MULTILINE)
     if err_m:
         nerr = int(err_m.group(1))
         nfail = 0
         return  nerr, nfail
 
     fail_m = re.search(r'^FAILED \(failures=(\d+)\)', txt, re.MULTILINE)
     if fail_m:
         nerr = 0
         nfail = int(fail_m.group(1))
         return  nerr, nfail
 
     both_m = re.search(r'^FAILED \(errors=(\d+), failures=(\d+)\)', txt,
                        re.MULTILINE)
     if both_m:
         nerr = int(both_m.group(1))
         nfail = int(both_m.group(2))
         return  nerr, nfail
 
     # If the input didn't match any of these forms, assume no error/failures
     return 0, 0
 
 
 # So nose doesn't think this is a test
 parse_test_output.__test__ = False
 
 
 def default_argv():
     """Return a valid default argv for creating testing instances of ipython"""
 
     return ['--quick', # so no config file is loaded
             # Other defaults to minimize side effects on stdout
             '--colors=NoColor', '--no-term-title','--no-banner',
             '--autocall=0']
 
 
 def default_config():
     """Return a config object with good defaults for testing."""
     config = Config()
     config.TerminalInteractiveShell.colors = 'NoColor'
     config.TerminalTerminalInteractiveShell.term_title = False,
     config.TerminalInteractiveShell.autocall = 0
     config.HistoryManager.hist_file = tempfile.mktemp(u'test_hist.sqlite')
     config.HistoryManager.db_cache_size = 10000
     return config
 
 
 def ipexec(fname, options=None):
     """Utility to call 'ipython filename'.
 
     Starts IPython witha minimal and safe configuration to make startup as fast
     as possible.
 
     Note that this starts IPython in a subprocess!
 
     Parameters
     ----------
     fname : str
       Name of file to be executed (should have .py or .ipy extension).
 
     options : optional, list
       Extra command-line flags to be passed to IPython.
 
     Returns
     -------
     (stdout, stderr) of ipython subprocess.
     """
     if options is None: options = []
 
     # For these subprocess calls, eliminate all prompt printing so we only see
     # output from script execution
     prompt_opts = [ '--PromptManager.in_template=""',
                     '--PromptManager.in2_template=""',
                     '--PromptManager.out_template=""'
     ]
     cmdargs = ' '.join(default_argv() + prompt_opts + options)
 
     _ip = get_ipython()
     test_dir = os.path.dirname(__file__)
 
     ipython_cmd = find_cmd('ipython3' if py3compat.PY3 else 'ipython')
     # Absolute path for filename
     full_fname = os.path.join(test_dir, fname)
     full_cmd = '%s %s %s' % (ipython_cmd, cmdargs, full_fname)
     #print >> sys.stderr, 'FULL CMD:', full_cmd # dbg
     out, err = getoutputerror(full_cmd)
     # `import readline` causes 'ESC[?1034h' to be output sometimes,
     # so strip that out before doing comparisons
     if out:
         out = re.sub(r'\x1b\[[^h]+h', '', out)
     return out, err
 
 
 def ipexec_validate(fname, expected_out, expected_err='',
                     options=None):
     """Utility to call 'ipython filename' and validate output/error.
 
     This function raises an AssertionError if the validation fails.
 
     Note that this starts IPython in a subprocess!
 
     Parameters
     ----------
     fname : str
       Name of the file to be executed (should have .py or .ipy extension).
 
     expected_out : str
       Expected stdout of the process.
 
     expected_err : optional, str
       Expected stderr of the process.
 
     options : optional, list
       Extra command-line flags to be passed to IPython.
 
     Returns
     -------
     None
     """
 
     import nose.tools as nt
 
     out, err = ipexec(fname, options)
     #print 'OUT', out  # dbg
     #print 'ERR', err  # dbg
     # If there are any errors, we must check those befor stdout, as they may be
     # more informative than simply having an empty stdout.
     if err:
         if expected_err:
             nt.assert_equals(err.strip(), expected_err.strip())
         else:
             raise ValueError('Running file %r produced error: %r' %
                              (fname, err))
     # If no errors or output on stderr was expected, match stdout
     nt.assert_equals(out.strip(), expected_out.strip())
 
 
 class TempFileMixin(object):
     """Utility class to create temporary Python/IPython files.
 
     Meant as a mixin class for test cases."""
 
     def mktmp(self, src, ext='.py'):
         """Make a valid python temp file."""
         fname, f = temp_pyfile(src, ext)
         self.tmpfile = f
         self.fname = fname
 
     def tearDown(self):
         if hasattr(self, 'tmpfile'):
             # If the tmpfile wasn't made because of skipped tests, like in
             # win32, there's nothing to cleanup.
             self.tmpfile.close()
             try:
                 os.unlink(self.fname)
             except:
                 # On Windows, even though we close the file, we still can't
                 # delete it.  I have no clue why
                 pass
 
 pair_fail_msg = ("Testing {0}\n\n"
                 "In:\n"
                 "  {1!r}\n"
                 "Expected:\n"
                 "  {2!r}\n"
                 "Got:\n"
                 "  {3!r}\n")
 def check_pairs(func, pairs):
     """Utility function for the common case of checking a function with a
     sequence of input/output pairs.
 
     Parameters
     ----------
     func : callable
       The function to be tested. Should accept a single argument.
     pairs : iterable
       A list of (input, expected_output) tuples.
 
     Returns
     -------
     None. Raises an AssertionError if any output does not match the expected
     value.
     """
     name = getattr(func, "func_name", getattr(func, "__name__", "<unknown>"))
     for inp, expected in pairs:
         out = func(inp)
         assert out == expected, pair_fail_msg.format(name, inp, expected, out)
 
 
 if py3compat.PY3:
     MyStringIO = StringIO
 else:
     # In Python 2, stdout/stderr can have either bytes or unicode written to them,
     # so we need a class that can handle both.
     class MyStringIO(StringIO):
         def write(self, s):
             s = py3compat.cast_unicode(s, encoding=getdefaultencoding())
             super(MyStringIO, self).write(s)
 
 notprinted_msg = """Did not find {0!r} in printed output (on {1}):
 {2!r}"""
 
 class AssertPrints(object):
     """Context manager for testing that code prints certain text.
     
     Examples
     --------
     >>> with AssertPrints("abc", suppress=False):
     ...     print "abcd"
     ...     print "def"
     ... 
     abcd
     def
     """
     def __init__(self, s, channel='stdout', suppress=True):
         self.s = s
         self.channel = channel
         self.suppress = suppress
     
     def __enter__(self):
         self.orig_stream = getattr(sys, self.channel)
         self.buffer = MyStringIO()
         self.tee = Tee(self.buffer, channel=self.channel)
         setattr(sys, self.channel, self.buffer if self.suppress else self.tee)
     
     def __exit__(self, etype, value, traceback):
         self.tee.flush()
         setattr(sys, self.channel, self.orig_stream)
         printed = self.buffer.getvalue()
         assert self.s in printed, notprinted_msg.format(self.s, self.channel, printed)
         return False
     
 class AssertNotPrints(AssertPrints):
     """Context manager for checking that certain output *isn't* produced.
     
     Counterpart of AssertPrints"""
     def __exit__(self, etype, value, traceback):
         self.tee.flush()
         setattr(sys, self.channel, self.orig_stream)
         printed = self.buffer.getvalue()
         assert self.s not in printed, notprinted_msg.format(self.s, self.channel, printed)
         return False
 
 @contextmanager
 def mute_warn():
     from IPython.utils import warn
     save_warn = warn.warn
     warn.warn = lambda *a, **kw: None
     try:
         yield
     finally:
         warn.warn = save_warn
 
 @contextmanager
 def make_tempfile(name):
     """ Create an empty, named, temporary file for the duration of the context.
     """
     f = open(name, 'w')
     f.close()
     try:
         yield
     finally:
         os.unlink(name)