TST: add future unicode_literals test (#786)

IPython/core/tests/test_interactiveshell.py

@@ -1,135 +1,148
 """Tests for the key interactiveshell module.
 
 Historically the main classes in interactiveshell have been under-tested.  This
 module should grow as many single-method tests as possible to trap many of the
 recurring bugs we seem to encounter with high-level interaction.
 
 Authors
 -------
 * Fernando Perez
 """
 #-----------------------------------------------------------------------------
 #  Copyright (C) 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 unittest
 from StringIO import StringIO
 
 from IPython.testing import decorators as dec
 from IPython.utils import io
 
 #-----------------------------------------------------------------------------
 # Tests
 #-----------------------------------------------------------------------------
 
 class InteractiveShellTestCase(unittest.TestCase):
     def test_naked_string_cells(self):
         """Test that cells with only naked strings are fully executed"""
         ip = get_ipython()
         # First, single-line inputs
         ip.run_cell('"a"\n')
         self.assertEquals(ip.user_ns['_'], 'a')
         # And also multi-line cells
         ip.run_cell('"""a\nb"""\n')
         self.assertEquals(ip.user_ns['_'], 'a\nb')
 
     def test_run_empty_cell(self):
         """Just make sure we don't get a horrible error with a blank
         cell of input. Yes, I did overlook that."""
         ip = get_ipython()
         old_xc = ip.execution_count
         ip.run_cell('')
         self.assertEquals(ip.execution_count, old_xc)
 
     def test_run_cell_multiline(self):
         """Multi-block, multi-line cells must execute correctly.
         """
         ip = get_ipython()
         src = '\n'.join(["x=1",
                          "y=2",
                          "if 1:",
                          "    x += 1",
                          "    y += 1",])
         ip.run_cell(src)
         self.assertEquals(ip.user_ns['x'], 2)
         self.assertEquals(ip.user_ns['y'], 3)
 
     def test_multiline_string_cells(self):
         "Code sprinkled with multiline strings should execute (GH-306)"
         ip = get_ipython()
         ip.run_cell('tmp=0')
         self.assertEquals(ip.user_ns['tmp'], 0)
         ip.run_cell('tmp=1;"""a\nb"""\n')
         self.assertEquals(ip.user_ns['tmp'], 1)
 
     def test_dont_cache_with_semicolon(self):
         "Ending a line with semicolon should not cache the returned object (GH-307)"
         ip = get_ipython()
         oldlen = len(ip.user_ns['Out'])
         a = ip.run_cell('1;')
         newlen = len(ip.user_ns['Out'])
         self.assertEquals(oldlen, newlen)
         #also test the default caching behavior
         ip.run_cell('1')
         newlen = len(ip.user_ns['Out'])
         self.assertEquals(oldlen+1, newlen)
 
     def test_In_variable(self):
         "Verify that In variable grows with user input (GH-284)"
         ip = get_ipython()
         oldlen = len(ip.user_ns['In'])
         ip.run_cell('1;')
         newlen = len(ip.user_ns['In'])
         self.assertEquals(oldlen+1, newlen)
         self.assertEquals(ip.user_ns['In'][-1],'1;')
         
     def test_magic_names_in_string(self):
         ip = get_ipython()
         ip.run_cell('a = """\n%exit\n"""')
         self.assertEquals(ip.user_ns['a'], '\n%exit\n')
     
     def test_alias_crash(self):
         """Errors in prefilter can't crash IPython"""
         ip = get_ipython()
         ip.run_cell('%alias parts echo first %s second %s')
         # capture stderr:
         save_err = io.stderr
         io.stderr = StringIO()
         ip.run_cell('parts 1')
         err = io.stderr.getvalue()
         io.stderr = save_err
         self.assertEquals(err.split(':')[0], 'ERROR')
     
     def test_trailing_newline(self):
         """test that running !(command) does not raise a SyntaxError"""
         ip = get_ipython()
         ip.run_cell('!(true)\n', False)
         ip.run_cell('!(true)\n\n\n', False)
     
     def test_gh_597(self):
         """Pretty-printing lists of objects with non-ascii reprs may cause
         problems."""
         class Spam(object):
           def __repr__(self):
             return "\xe9"*50
         import IPython.core.formatters
         f = IPython.core.formatters.PlainTextFormatter()
         f([Spam(),Spam()])
     
     def test_future_flags(self):
         """Check that future flags are used for parsing code (gh-777)"""
         ip = get_ipython()
         ip.run_cell('from __future__ import print_function')
         try:
             ip.run_cell('prfunc_return_val = print(1,2, sep=" ")')
             assert 'prfunc_return_val' in ip.user_ns
         finally:
             # Reset compiler flags so we don't mess up other tests.
             ip.compile.reset_compiler_flags()
+
+    def test_future_unicode(self):
+        """Check that unicode_literals is imported from __future__ (gh #786)"""
+        ip = get_ipython()
+        try:
+            ip.run_cell(u'len_byte_str = len("\xe9")')
+            assert ip.user_ns['len_byte_str'] == 2
+            ip.run_cell('from __future__ import unicode_literals')
+            ip.run_cell(u'len_unicode_str = len("\xe9")')
+            assert ip.user_ns['len_unicode_str'] == 1
+        finally:
+            # Reset compiler flags so we don't mess up other tests.
+            ip.compile.reset_compiler_flags()