Use AssertPrints in tests for autoreload extension.

IPython/extensions/tests/test_autoreload.py

@@ -1,307 +1,300 b''
 import os
 import sys
 import tempfile
 import shutil
 import random
 import time
 from StringIO import StringIO
 
 import nose.tools as nt
+import IPython.testing.tools as tt
 
 from IPython.extensions.autoreload import AutoreloadInterface
 from IPython.core.hooks import TryNext
 
 #-----------------------------------------------------------------------------
 # Test fixture
 #-----------------------------------------------------------------------------
 
 class FakeShell(object):
     def __init__(self):
         self.ns = {}
         self.reloader = AutoreloadInterface()
 
     def run_code(self, code):
         try:
             self.reloader.pre_run_code_hook(self)
         except TryNext:
             pass
         exec code in self.ns
 
     def push(self, items):
         self.ns.update(items)
 
     def magic_autoreload(self, parameter):
         self.reloader.magic_autoreload(self, parameter)
 
     def magic_aimport(self, parameter, stream=None):
         self.reloader.magic_aimport(self, parameter, stream=stream)
 
 
 class Fixture(object):
     """Fixture for creating test module files"""
 
     test_dir = None
     old_sys_path = None
     filename_chars = "abcdefghijklmopqrstuvwxyz0123456789"
 
     def setUp(self):
         self.test_dir = tempfile.mkdtemp()
         self.old_sys_path = list(sys.path)
         sys.path.insert(0, self.test_dir)
         self.shell = FakeShell()
 
     def tearDown(self):
         shutil.rmtree(self.test_dir)
         sys.path = self.old_sys_path
         self.shell.reloader.enabled = False
 
         self.test_dir = None
         self.old_sys_path = None
         self.shell = None
 
     def get_module(self):
         module_name = "tmpmod_" + "".join(random.sample(self.filename_chars,20))
         if module_name in sys.modules:
             del sys.modules[module_name]
         file_name = os.path.join(self.test_dir, module_name + ".py")
         return module_name, file_name
 
     def write_file(self, filename, content):
         """
         Write a file, and force a timestamp difference of at least one second
 
         Notes
         -----
         Python's .pyc files record the timestamp of their compilation
         with a time resolution of one second.
 
         Therefore, we need to force a timestamp difference between .py
         and .pyc, without having the .py file be timestamped in the
         future, and without changing the timestamp of the .pyc file
         (because that is stored in the file).  The only reliable way
         to achieve this seems to be to sleep.
 
         """
 
         # Sleep one second + eps
         time.sleep(1.05)
 
         # Write
         f = open(filename, 'w')
         try:
             f.write(content)
         finally:
             f.close()
 
     def new_module(self, code):
         mod_name, mod_fn = self.get_module()
         f = open(mod_fn, 'w')
         try:
             f.write(code)
         finally:
             f.close()
         return mod_name, mod_fn
 
 #-----------------------------------------------------------------------------
 # Test automatic reloading
 #-----------------------------------------------------------------------------
 
 class TestAutoreload(Fixture):
     def _check_smoketest(self, use_aimport=True):
         """
         Functional test for the automatic reloader using either
         '%autoreload 1' or '%autoreload 2'
         """
 
         mod_name, mod_fn = self.new_module("""
 x = 9
 
 z = 123  # this item will be deleted
 
 def foo(y):
     return y + 3
 
 class Baz(object):
     def __init__(self, x):
         self.x = x
     def bar(self, y):
         return self.x + y
     @property
     def quux(self):
         return 42
     def zzz(self):
         '''This method will be deleted below'''
         return 99
 
 class Bar:    # old-style class: weakref doesn't work for it on Python < 2.7
     def foo(self):
         return 1
 """)
 
         #
         # Import module, and mark for reloading
         #
         if use_aimport:
             self.shell.magic_autoreload("1")
             self.shell.magic_aimport(mod_name)
             stream = StringIO()
             self.shell.magic_aimport("", stream=stream)
             nt.assert_true(("Modules to reload:\n%s" % mod_name) in
                            stream.getvalue())
 
             nt.assert_raises(
                 ImportError,
                 self.shell.magic_aimport, "tmpmod_as318989e89ds")
         else:
             self.shell.magic_autoreload("2")
             self.shell.run_code("import %s" % mod_name)
             stream = StringIO()
             self.shell.magic_aimport("", stream=stream)
             nt.assert_true("Modules to reload:\nall-except-skipped" in
                            stream.getvalue())
         nt.assert_true(mod_name in self.shell.ns)
 
         mod = sys.modules[mod_name]
 
         #
         # Test module contents
         #
         old_foo = mod.foo
         old_obj = mod.Baz(9)
         old_obj2 = mod.Bar()
 
         def check_module_contents():
             nt.assert_equal(mod.x, 9)
             nt.assert_equal(mod.z, 123)
 
             nt.assert_equal(old_foo(0), 3)
             nt.assert_equal(mod.foo(0), 3)
 
             obj = mod.Baz(9)
             nt.assert_equal(old_obj.bar(1), 10)
             nt.assert_equal(obj.bar(1), 10)
             nt.assert_equal(obj.quux, 42)
             nt.assert_equal(obj.zzz(), 99)
 
             obj2 = mod.Bar()
             nt.assert_equal(old_obj2.foo(), 1)
             nt.assert_equal(obj2.foo(), 1)
 
         check_module_contents()
 
         #
         # Simulate a failed reload: no reload should occur and exactly
         # one error message should be printed
         #
         self.write_file(mod_fn, """
 a syntax error
 """)
 
-        old_stderr = sys.stderr
-        new_stderr = StringIO()
-        sys.stderr = new_stderr
-        try:
+        with tt.AssertPrints(('[autoreload of %s failed:' % mod_name), channel='stderr'):
             self.shell.run_code("pass") # trigger reload
+        with tt.AssertNotPrints(('[autoreload of %s failed:' % mod_name), channel='stderr'):
             self.shell.run_code("pass") # trigger another reload
-            check_module_contents()
-        finally:
-            sys.stderr = old_stderr
-
-        nt.assert_true(('[autoreload of %s failed:' % mod_name) in
-                       new_stderr.getvalue())
-        nt.assert_equal(new_stderr.getvalue().count('[autoreload of'), 1)
+        check_module_contents()
 
         #
         # Rewrite module (this time reload should succeed)
         #
         self.write_file(mod_fn, """
 x = 10
 
 def foo(y):
     return y + 4
 
 class Baz(object):
     def __init__(self, x):
         self.x = x
     def bar(self, y):
         return self.x + y + 1
     @property
     def quux(self):
         return 43
 
 class Bar:    # old-style class
     def foo(self):
         return 2
 """)
 
         def check_module_contents():
             nt.assert_equal(mod.x, 10)
             nt.assert_false(hasattr(mod, 'z'))
 
             nt.assert_equal(old_foo(0), 4) # superreload magic!
             nt.assert_equal(mod.foo(0), 4)
 
             obj = mod.Baz(9)
             nt.assert_equal(old_obj.bar(1), 11) # superreload magic!
             nt.assert_equal(obj.bar(1), 11)
 
             nt.assert_equal(old_obj.quux, 43)
             nt.assert_equal(obj.quux, 43)
 
             nt.assert_false(hasattr(old_obj, 'zzz'))
             nt.assert_false(hasattr(obj, 'zzz'))
 
             obj2 = mod.Bar()
             nt.assert_equal(old_obj2.foo(), 2)
             nt.assert_equal(obj2.foo(), 2)
 
         self.shell.run_code("pass") # trigger reload
         check_module_contents()
 
         #
         # Another failure case: deleted file (shouldn't reload)
         #
         os.unlink(mod_fn)
 
         self.shell.run_code("pass") # trigger reload
         check_module_contents()
 
         #
         # Disable autoreload and rewrite module: no reload should occur
         #
         if use_aimport:
             self.shell.magic_aimport("-" + mod_name)
             stream = StringIO()
             self.shell.magic_aimport("", stream=stream)
             nt.assert_true(("Modules to skip:\n%s" % mod_name) in
                            stream.getvalue())
 
             # This should succeed, although no such module exists
             self.shell.magic_aimport("-tmpmod_as318989e89ds")
         else:
             self.shell.magic_autoreload("0")
 
         self.write_file(mod_fn, """
 x = -99
 """)
 
         self.shell.run_code("pass") # trigger reload
         self.shell.run_code("pass")
         check_module_contents()
 
         #
         # Re-enable autoreload: reload should now occur
         #
         if use_aimport:
             self.shell.magic_aimport(mod_name)
         else:
             self.shell.magic_autoreload("")
 
         self.shell.run_code("pass") # trigger reload
         nt.assert_equal(mod.x, -99)
 
     def test_smoketest_aimport(self):
         self._check_smoketest(use_aimport=True)
 
     def test_smoketest_autoreload(self):
         self._check_smoketest(use_aimport=False)

IPython/testing/tools.py

@@ -1,388 +1,400 b''
 """Generic testing tools that do NOT depend on Twisted.
 
 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  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 = [ '--InteractiveShell.prompt_in1=""',
                     '--InteractiveShell.prompt_in2=""',
                     '--InteractiveShell.prompt_out=""'
     ]
     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 = getoutputerror(full_cmd)
     # `import readline` causes 'ESC[?1034h' to be the first output sometimes,
     # so strip that off the front of the first line if it is found
     if out:
         first = out[0]
         m = re.match(r'\x1b\[[^h]+h', first)
         if m:
             # strip initial readline escape
             out = list(out)
             out[0] = first[len(m.group()):]
             out = tuple(out)
     return out
 
 
 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)
     #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"):
+    >>> with AssertPrints("abc", suppress=False):
     ...     print "abcd"
     ...     print "def"
     ... 
     abcd
     def
     """
-    def __init__(self, s, channel='stdout'):
+    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.tee)
+        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)