Add failing test for issue gh-1456

IPython/core/tests/test_ultratb.py

@@ -0,0 +1,51 b''
+"""Tests for IPython.core.ultratb
+"""
+
+import os.path
+import unittest
+
+from IPython.testing import tools as tt
+from IPython.utils.syspathcontext import prepended_to_syspath
+from IPython.utils.tempdir import TemporaryDirectory
+
+ip = get_ipython()
+
+file_1 = """1
+2
+3
+def f():
+  1/0
+"""
+
+file_2 = """def f():
+  1/0
+"""
+
+class ChangedPyFileTest(unittest.TestCase):
+    def test_changing_py_file(self):
+        """Traceback produced if the line where the error occurred is missing?
+        
+        https://github.com/ipython/ipython/issues/1456
+        """
+        with TemporaryDirectory() as td:
+            fname = os.path.join(td, "foo.py")
+            with open(fname, "w") as f:
+                f.write(file_1)
+            
+            with prepended_to_syspath(td):
+                ip.run_cell("import foo")
+            
+            with tt.AssertPrints("ZeroDivisionError"):
+                ip.run_cell("foo.f()")
+            
+            # Make the file shorter, so the line of the error is missing.
+            with open(fname, "w") as f:
+                f.write(file_2)
+            
+            # For some reason, this was failing on the *second* call after
+            # changing the file, so we call f() twice.
+            with tt.AssertNotPrints("Internal Python error", channel='stderr'):
+                with tt.AssertPrints("ZeroDivisionError"):
+                    ip.run_cell("foo.f()")
+                with tt.AssertPrints("ZeroDivisionError"):
+                    ip.run_cell("foo.f()")

IPython/testing/tools.py

@@ -1,382 +1,391 b''
 """Generic testing tools.
 
 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
 from IPython.utils.io import temp_pyfile, Tee
 from IPython.utils import py3compat
 from IPython.utils.encoding import DEFAULT_ENCODING
 
 from . import decorators as dec
 from . import skipdoctest
 
 #-----------------------------------------------------------------------------
 # 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_equal(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_equal(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=DEFAULT_ENCODING)
             super(MyStringIO, self).write(s)
 
 notprinted_msg = """Did not find {0!r} in printed output (on {1}):
-{2!r}"""
+-------
+{2!s}
+-------
+"""
 
 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
-    
+
+printed_msg = """Found {0!r} in printed output (on {1}):
+-------
+{2!s}
+-------
+"""
+
 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)
+        assert self.s not in printed, printed_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)
 
 
 @contextmanager
 def monkeypatch(obj, name, attr):
     """
     Context manager to replace attribute named `name` in `obj` with `attr`.
     """
     orig = getattr(obj, name)
     setattr(obj, name, attr)
     yield
     setattr(obj, name, orig)