IPython/core/tests/test_interactiveshell.py

# -*- coding: utf-8 -*-
"""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.
"""

# Copyright (c) IPython Development Team.
# Distributed under the terms of the Modified BSD License.

import ast
import os
import signal
import shutil
import sys
import tempfile
import unittest
try:
    from unittest import mock
except ImportError:
    import mock
from os.path import join

import nose.tools as nt

from IPython.core.inputtransformer import InputTransformer
from IPython.testing.decorators import (
    skipif, skip_win32, onlyif_unicode_paths, onlyif_cmds_exist,
)
from IPython.testing import tools as tt
from IPython.utils import io
from IPython.utils.process import find_cmd
from IPython.utils import py3compat
from IPython.utils.py3compat import unicode_type, PY3

if PY3:
    from io import StringIO
else:
    from StringIO import StringIO

#-----------------------------------------------------------------------------
# Globals
#-----------------------------------------------------------------------------
# This is used by every single test, no point repeating it ad nauseam
ip = get_ipython()

#-----------------------------------------------------------------------------
# Tests
#-----------------------------------------------------------------------------

class InteractiveShellTestCase(unittest.TestCase):
    def test_naked_string_cells(self):
        """Test that cells with only naked strings are fully executed"""
        # First, single-line inputs
        ip.run_cell('"a"\n')
        self.assertEqual(ip.user_ns['_'], 'a')
        # And also multi-line cells
        ip.run_cell('"""a\nb"""\n')
        self.assertEqual(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."""
        old_xc = ip.execution_count
        ip.run_cell('')
        self.assertEqual(ip.execution_count, old_xc)

    def test_run_cell_multiline(self):
        """Multi-block, multi-line cells must execute correctly.
        """
        src = '\n'.join(["x=1",
                         "y=2",
                         "if 1:",
                         "    x += 1",
                         "    y += 1",])
        ip.run_cell(src)
        self.assertEqual(ip.user_ns['x'], 2)
        self.assertEqual(ip.user_ns['y'], 3)

    def test_multiline_string_cells(self):
        "Code sprinkled with multiline strings should execute (GH-306)"
        ip.run_cell('tmp=0')
        self.assertEqual(ip.user_ns['tmp'], 0)
        ip.run_cell('tmp=1;"""a\nb"""\n')
        self.assertEqual(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)"
        oldlen = len(ip.user_ns['Out'])
        for cell in ['1;', '1;1;']:
            ip.run_cell(cell, store_history=True)
            newlen = len(ip.user_ns['Out'])
            self.assertEqual(oldlen, newlen)
        i = 0
        #also test the default caching behavior
        for cell in ['1', '1;1']:
            ip.run_cell(cell, store_history=True)
            newlen = len(ip.user_ns['Out'])
            i += 1
            self.assertEqual(oldlen+i, newlen)

    def test_In_variable(self):
        "Verify that In variable grows with user input (GH-284)"
        oldlen = len(ip.user_ns['In'])
        ip.run_cell('1;', store_history=True)
        newlen = len(ip.user_ns['In'])
        self.assertEqual(oldlen+1, newlen)
        self.assertEqual(ip.user_ns['In'][-1],'1;')
        
    def test_magic_names_in_string(self):
        ip.run_cell('a = """\n%exit\n"""')
        self.assertEqual(ip.user_ns['a'], '\n%exit\n')
    
    def test_trailing_newline(self):
        """test that running !(command) does not raise a SyntaxError"""
        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.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)"""
        try:
            ip.run_cell(u'byte_str = "a"')
            assert isinstance(ip.user_ns['byte_str'], str) # string literals are byte strings by default
            ip.run_cell('from __future__ import unicode_literals')
            ip.run_cell(u'unicode_str = "a"')
            assert isinstance(ip.user_ns['unicode_str'], unicode_type) # strings literals are now unicode
        finally:
            # Reset compiler flags so we don't mess up other tests.
            ip.compile.reset_compiler_flags()
    
    def test_can_pickle(self):
        "Can we pickle objects defined interactively (GH-29)"
        ip = get_ipython()
        ip.reset()
        ip.run_cell(("class Mylist(list):\n"
                     "    def __init__(self,x=[]):\n"
                     "        list.__init__(self,x)"))
        ip.run_cell("w=Mylist([1,2,3])")
        
        from pickle import dumps
        
        # We need to swap in our main module - this is only necessary
        # inside the test framework, because IPython puts the interactive module
        # in place (but the test framework undoes this).
        _main = sys.modules['__main__']
        sys.modules['__main__'] = ip.user_module
        try:
            res = dumps(ip.user_ns["w"])
        finally:
            sys.modules['__main__'] = _main
        self.assertTrue(isinstance(res, bytes))
        
    def test_global_ns(self):
        "Code in functions must be able to access variables outside them."
        ip = get_ipython()
        ip.run_cell("a = 10")
        ip.run_cell(("def f(x):\n"
                     "    return x + a"))
        ip.run_cell("b = f(12)")
        self.assertEqual(ip.user_ns["b"], 22)

    def test_bad_custom_tb(self):
        """Check that InteractiveShell is protected from bad custom exception handlers"""
        from IPython.utils import io
        save_stderr = io.stderr
        try:
            # capture stderr
            io.stderr = StringIO()
            ip.set_custom_exc((IOError,), lambda etype,value,tb: 1/0)
            self.assertEqual(ip.custom_exceptions, (IOError,))
            ip.run_cell(u'raise IOError("foo")')
            self.assertEqual(ip.custom_exceptions, ())
            self.assertTrue("Custom TB Handler failed" in io.stderr.getvalue())
        finally:
            io.stderr = save_stderr

    def test_bad_custom_tb_return(self):
        """Check that InteractiveShell is protected from bad return types in custom exception handlers"""
        from IPython.utils import io
        save_stderr = io.stderr
        try:
            # capture stderr
            io.stderr = StringIO()
            ip.set_custom_exc((NameError,),lambda etype,value,tb, tb_offset=None: 1)
            self.assertEqual(ip.custom_exceptions, (NameError,))
            ip.run_cell(u'a=abracadabra')
            self.assertEqual(ip.custom_exceptions, ())
            self.assertTrue("Custom TB Handler failed" in io.stderr.getvalue())
        finally:
            io.stderr = save_stderr

    def test_drop_by_id(self):
        myvars = {"a":object(), "b":object(), "c": object()}
        ip.push(myvars, interactive=False)
        for name in myvars:
            assert name in ip.user_ns, name
            assert name in ip.user_ns_hidden, name
        ip.user_ns['b'] = 12
        ip.drop_by_id(myvars)
        for name in ["a", "c"]:
            assert name not in ip.user_ns, name
            assert name not in ip.user_ns_hidden, name
        assert ip.user_ns['b'] == 12
        ip.reset()

    def test_var_expand(self):
        ip.user_ns['f'] = u'Ca\xf1o'
        self.assertEqual(ip.var_expand(u'echo $f'), u'echo Ca\xf1o')
        self.assertEqual(ip.var_expand(u'echo {f}'), u'echo Ca\xf1o')
        self.assertEqual(ip.var_expand(u'echo {f[:-1]}'), u'echo Ca\xf1')
        self.assertEqual(ip.var_expand(u'echo {1*2}'), u'echo 2')

        ip.user_ns['f'] = b'Ca\xc3\xb1o'
        # This should not raise any exception:
        ip.var_expand(u'echo $f')
    
    def test_var_expand_local(self):
        """Test local variable expansion in !system and %magic calls"""
        # !system
        ip.run_cell('def test():\n'
                    '    lvar = "ttt"\n'
                    '    ret = !echo {lvar}\n'
                    '    return ret[0]\n')
        res = ip.user_ns['test']()
        nt.assert_in('ttt', res)
        
        # %magic
        ip.run_cell('def makemacro():\n'
                    '    macroname = "macro_var_expand_locals"\n'
                    '    %macro {macroname} codestr\n')
        ip.user_ns['codestr'] = "str(12)"
        ip.run_cell('makemacro()')
        nt.assert_in('macro_var_expand_locals', ip.user_ns)
    
    def test_var_expand_self(self):
        """Test variable expansion with the name 'self', which was failing.
        
        See https://github.com/ipython/ipython/issues/1878#issuecomment-7698218
        """
        ip.run_cell('class cTest:\n'
                    '  classvar="see me"\n'
                    '  def test(self):\n'
                    '    res = !echo Variable: {self.classvar}\n'
                    '    return res[0]\n')
        nt.assert_in('see me', ip.user_ns['cTest']().test())
    
    def test_bad_var_expand(self):
        """var_expand on invalid formats shouldn't raise"""
        # SyntaxError
        self.assertEqual(ip.var_expand(u"{'a':5}"), u"{'a':5}")
        # NameError
        self.assertEqual(ip.var_expand(u"{asdf}"), u"{asdf}")
        # ZeroDivisionError
        self.assertEqual(ip.var_expand(u"{1/0}"), u"{1/0}")
    
    def test_silent_postexec(self):
        """run_cell(silent=True) doesn't invoke pre/post_run_cell callbacks"""
        pre_explicit = mock.Mock()
        pre_always = mock.Mock()
        post_explicit = mock.Mock()
        post_always = mock.Mock()
        
        ip.events.register('pre_run_cell', pre_explicit)
        ip.events.register('pre_execute', pre_always)
        ip.events.register('post_run_cell', post_explicit)
        ip.events.register('post_execute', post_always)
        
        try:
            ip.run_cell("1", silent=True)
            assert pre_always.called
            assert not pre_explicit.called
            assert post_always.called
            assert not post_explicit.called
            # double-check that non-silent exec did what we expected
            # silent to avoid
            ip.run_cell("1")
            assert pre_explicit.called
            assert post_explicit.called
        finally:
            # remove post-exec
            ip.events.reset_all()
    
    def test_silent_noadvance(self):
        """run_cell(silent=True) doesn't advance execution_count"""
        ec = ip.execution_count
        # silent should force store_history=False
        ip.run_cell("1", store_history=True, silent=True)
        
        self.assertEqual(ec, ip.execution_count)
        # double-check that non-silent exec did what we expected
        # silent to avoid
        ip.run_cell("1", store_history=True)
        self.assertEqual(ec+1, ip.execution_count)
    
    def test_silent_nodisplayhook(self):
        """run_cell(silent=True) doesn't trigger displayhook"""
        d = dict(called=False)
        
        trap = ip.display_trap
        save_hook = trap.hook
        
        def failing_hook(*args, **kwargs):
            d['called'] = True
        
        try:
            trap.hook = failing_hook
            ip.run_cell("1", silent=True)
            self.assertFalse(d['called'])
            # double-check that non-silent exec did what we expected
            # silent to avoid
            ip.run_cell("1")
            self.assertTrue(d['called'])
        finally:
            trap.hook = save_hook

    @skipif(sys.version_info[0] >= 3, "softspace removed in py3")
    def test_print_softspace(self):
        """Verify that softspace is handled correctly when executing multiple
        statements.

        In [1]: print 1; print 2
        1
        2

        In [2]: print 1,; print 2
        1 2
        """
        
    def test_ofind_line_magic(self):
        from IPython.core.magic import register_line_magic
        
        @register_line_magic
        def lmagic(line):
            "A line magic"

        # Get info on line magic
        lfind = ip._ofind('lmagic')
        info = dict(found=True, isalias=False, ismagic=True,
                    namespace = 'IPython internal', obj= lmagic.__wrapped__,
                    parent = None)
        nt.assert_equal(lfind, info)
        
    def test_ofind_cell_magic(self):
        from IPython.core.magic import register_cell_magic
        
        @register_cell_magic
        def cmagic(line, cell):
            "A cell magic"

        # Get info on cell magic
        find = ip._ofind('cmagic')
        info = dict(found=True, isalias=False, ismagic=True,
                    namespace = 'IPython internal', obj= cmagic.__wrapped__,
                    parent = None)
        nt.assert_equal(find, info)

    def test_ofind_property_with_error(self):
        class A(object):
            @property
            def foo(self):
                raise NotImplementedError()
        a = A()

        found = ip._ofind('a.foo', [('locals', locals())])
        info = dict(found=True, isalias=False, ismagic=False,
                    namespace='locals', obj=A.foo, parent=a)
        nt.assert_equal(found, info)

    def test_ofind_multiple_attribute_lookups(self):
        class A(object):
            @property
            def foo(self):
                raise NotImplementedError()

        a = A()
        a.a = A()
        a.a.a = A()

        found = ip._ofind('a.a.a.foo', [('locals', locals())])
        info = dict(found=True, isalias=False, ismagic=False,
                    namespace='locals', obj=A.foo, parent=a.a.a)
        nt.assert_equal(found, info)

    def test_ofind_slotted_attributes(self):
        class A(object):
            __slots__ = ['foo']
            def __init__(self):
                self.foo = 'bar'

        a = A()
        found = ip._ofind('a.foo', [('locals', locals())])
        info = dict(found=True, isalias=False, ismagic=False,
                    namespace='locals', obj=a.foo, parent=a)
        nt.assert_equal(found, info)

        found = ip._ofind('a.bar', [('locals', locals())])
        info = dict(found=False, isalias=False, ismagic=False,
                    namespace=None, obj=None, parent=a)
        nt.assert_equal(found, info)

    def test_ofind_prefers_property_to_instance_level_attribute(self):
        class A(object):
            @property
            def foo(self):
                return 'bar'
        a = A()
        a.__dict__['foo'] = 'baz'
        nt.assert_equal(a.foo, 'bar')
        found = ip._ofind('a.foo', [('locals', locals())])
        nt.assert_is(found['obj'], A.foo)

    def test_custom_exception(self):
        called = []
        def my_handler(shell, etype, value, tb, tb_offset=None):
            called.append(etype)
            shell.showtraceback((etype, value, tb), tb_offset=tb_offset)
        
        ip.set_custom_exc((ValueError,), my_handler)
        try:
            ip.run_cell("raise ValueError('test')")
            # Check that this was called, and only once.
            self.assertEqual(called, [ValueError])
        finally:
            # Reset the custom exception hook
            ip.set_custom_exc((), None)
    
    @skipif(sys.version_info[0] >= 3, "no differences with __future__ in py3")
    def test_future_environment(self):
        "Can we run code with & without the shell's __future__ imports?"
        ip.run_cell("from __future__ import division")
        ip.run_cell("a = 1/2", shell_futures=True)
        self.assertEqual(ip.user_ns['a'], 0.5)
        ip.run_cell("b = 1/2", shell_futures=False)
        self.assertEqual(ip.user_ns['b'], 0)
        
        ip.compile.reset_compiler_flags()
        # This shouldn't leak to the shell's compiler
        ip.run_cell("from __future__ import division \nc=1/2", shell_futures=False)
        self.assertEqual(ip.user_ns['c'], 0.5)
        ip.run_cell("d = 1/2", shell_futures=True)
        self.assertEqual(ip.user_ns['d'], 0)

    def test_mktempfile(self):
        filename = ip.mktempfile()
        # Check that we can open the file again on Windows
        with open(filename, 'w') as f:
            f.write('abc')

        filename = ip.mktempfile(data='blah')
        with open(filename, 'r') as f:
            self.assertEqual(f.read(), 'blah')

    def test_new_main_mod(self):
        # Smoketest to check that this accepts a unicode module name
        name = u'jiefmw'
        mod = ip.new_main_mod(u'%s.py' % name, name)
        self.assertEqual(mod.__name__, name)

class TestSafeExecfileNonAsciiPath(unittest.TestCase):

    @onlyif_unicode_paths
    def setUp(self):
        self.BASETESTDIR = tempfile.mkdtemp()
        self.TESTDIR = join(self.BASETESTDIR, u"åäö")
        os.mkdir(self.TESTDIR)
        with open(join(self.TESTDIR, u"åäötestscript.py"), "w") as sfile:
            sfile.write("pass\n")
        self.oldpath = py3compat.getcwd()
        os.chdir(self.TESTDIR)
        self.fname = u"åäötestscript.py"

    def tearDown(self):
        os.chdir(self.oldpath)
        shutil.rmtree(self.BASETESTDIR)

    @onlyif_unicode_paths
    def test_1(self):
        """Test safe_execfile with non-ascii path
        """
        ip.safe_execfile(self.fname, {}, raise_exceptions=True)

class ExitCodeChecks(tt.TempFileMixin):
    def test_exit_code_ok(self):
        self.system('exit 0')
        self.assertEqual(ip.user_ns['_exit_code'], 0)

    def test_exit_code_error(self):
        self.system('exit 1')
        self.assertEqual(ip.user_ns['_exit_code'], 1)
    
    @skipif(not hasattr(signal, 'SIGALRM'))
    def test_exit_code_signal(self):
        self.mktmp("import signal, time\n"
                   "signal.setitimer(signal.ITIMER_REAL, 0.1)\n"
                   "time.sleep(1)\n")
        self.system("%s %s" % (sys.executable, self.fname))
        self.assertEqual(ip.user_ns['_exit_code'], -signal.SIGALRM)
    
    @onlyif_cmds_exist("csh")
    def test_exit_code_signal_csh(self):
        SHELL = os.environ.get('SHELL', None)
        os.environ['SHELL'] = find_cmd("csh")
        try:
            self.test_exit_code_signal()
        finally:
            if SHELL is not None:
                os.environ['SHELL'] = SHELL
            else:
                del os.environ['SHELL']

class TestSystemRaw(unittest.TestCase, ExitCodeChecks):
    system = ip.system_raw

    @onlyif_unicode_paths
    def test_1(self):
        """Test system_raw with non-ascii cmd
        """
        cmd = u'''python -c "'åäö'"   '''
        ip.system_raw(cmd)

# TODO: Exit codes are currently ignored on Windows.
class TestSystemPipedExitCode(unittest.TestCase, ExitCodeChecks):
    system = ip.system_piped

    @skip_win32
    def test_exit_code_ok(self):
        ExitCodeChecks.test_exit_code_ok(self)

    @skip_win32
    def test_exit_code_error(self):
        ExitCodeChecks.test_exit_code_error(self)

    @skip_win32
    def test_exit_code_signal(self):
        ExitCodeChecks.test_exit_code_signal(self)

class TestModules(unittest.TestCase, tt.TempFileMixin):
    def test_extraneous_loads(self):
        """Test we're not loading modules on startup that we shouldn't.
        """
        self.mktmp("import sys\n"
                   "print('numpy' in sys.modules)\n"
                   "print('IPython.parallel' in sys.modules)\n"
                   "print('IPython.kernel.zmq' in sys.modules)\n"
                   )
        out = "False\nFalse\nFalse\n"
        tt.ipexec_validate(self.fname, out)

class Negator(ast.NodeTransformer):
    """Negates all number literals in an AST."""
    def visit_Num(self, node):
        node.n = -node.n
        return node

class TestAstTransform(unittest.TestCase):
    def setUp(self):
        self.negator = Negator()
        ip.ast_transformers.append(self.negator)
    
    def tearDown(self):
        ip.ast_transformers.remove(self.negator)
    
    def test_run_cell(self):
        with tt.AssertPrints('-34'):
            ip.run_cell('print (12 + 22)')
        
        # A named reference to a number shouldn't be transformed.
        ip.user_ns['n'] = 55
        with tt.AssertNotPrints('-55'):
            ip.run_cell('print (n)')
    
    def test_timeit(self):
        called = set()
        def f(x):
            called.add(x)
        ip.push({'f':f})
        
        with tt.AssertPrints("best of "):
            ip.run_line_magic("timeit", "-n1 f(1)")
        self.assertEqual(called, set([-1]))
        called.clear()
        
        with tt.AssertPrints("best of "):
            ip.run_cell_magic("timeit", "-n1 f(2)", "f(3)")
        self.assertEqual(called, set([-2, -3]))
    
    def test_time(self):
        called = []
        def f(x):
            called.append(x)
        ip.push({'f':f})
        
        # Test with an expression
        with tt.AssertPrints("Wall time: "):
            ip.run_line_magic("time", "f(5+9)")
        self.assertEqual(called, [-14])
        called[:] = []
        
        # Test with a statement (different code path)
        with tt.AssertPrints("Wall time: "):
            ip.run_line_magic("time", "a = f(-3 + -2)")
        self.assertEqual(called, [5])
    
    def test_macro(self):
        ip.push({'a':10})
        # The AST transformation makes this do a+=-1
        ip.define_macro("amacro", "a+=1\nprint(a)")
        
        with tt.AssertPrints("9"):
            ip.run_cell("amacro")
        with tt.AssertPrints("8"):
            ip.run_cell("amacro")

class IntegerWrapper(ast.NodeTransformer):
    """Wraps all integers in a call to Integer()"""
    def visit_Num(self, node):
        if isinstance(node.n, int):
            return ast.Call(func=ast.Name(id='Integer', ctx=ast.Load()),
                            args=[node], keywords=[])
        return node

class TestAstTransform2(unittest.TestCase):
    def setUp(self):
        self.intwrapper = IntegerWrapper()
        ip.ast_transformers.append(self.intwrapper)
        
        self.calls = []
        def Integer(*args):
            self.calls.append(args)
            return args
        ip.push({"Integer": Integer})
    
    def tearDown(self):
        ip.ast_transformers.remove(self.intwrapper)
        del ip.user_ns['Integer']
    
    def test_run_cell(self):
        ip.run_cell("n = 2")
        self.assertEqual(self.calls, [(2,)])
        
        # This shouldn't throw an error
        ip.run_cell("o = 2.0")
        self.assertEqual(ip.user_ns['o'], 2.0)
    
    def test_timeit(self):
        called = set()
        def f(x):
            called.add(x)
        ip.push({'f':f})
        
        with tt.AssertPrints("best of "):
            ip.run_line_magic("timeit", "-n1 f(1)")
        self.assertEqual(called, set([(1,)]))
        called.clear()
        
        with tt.AssertPrints("best of "):
            ip.run_cell_magic("timeit", "-n1 f(2)", "f(3)")
        self.assertEqual(called, set([(2,), (3,)]))

class ErrorTransformer(ast.NodeTransformer):
    """Throws an error when it sees a number."""
    def visit_Num(self):
        raise ValueError("test")

class TestAstTransformError(unittest.TestCase):
    def test_unregistering(self):
        err_transformer = ErrorTransformer()
        ip.ast_transformers.append(err_transformer)
        
        with tt.AssertPrints("unregister", channel='stderr'):
            ip.run_cell("1 + 2")
        
        # This should have been removed.
        nt.assert_not_in(err_transformer, ip.ast_transformers)

def test__IPYTHON__():
    # This shouldn't raise a NameError, that's all
    __IPYTHON__


class DummyRepr(object):
    def __repr__(self):
        return "DummyRepr"
    
    def _repr_html_(self):
        return "<b>dummy</b>"
    
    def _repr_javascript_(self):
        return "console.log('hi');", {'key': 'value'}
    

def test_user_variables():
    # enable all formatters
    ip.display_formatter.active_types = ip.display_formatter.format_types
    
    ip.user_ns['dummy'] = d = DummyRepr()
    keys = set(['dummy', 'doesnotexist'])
    r = ip.user_expressions({ key:key for key in keys})

    nt.assert_equal(keys, set(r.keys()))
    dummy = r['dummy']
    nt.assert_equal(set(['status', 'data', 'metadata']), set(dummy.keys()))
    nt.assert_equal(dummy['status'], 'ok')
    data = dummy['data']
    metadata = dummy['metadata']
    nt.assert_equal(data.get('text/html'), d._repr_html_())
    js, jsmd = d._repr_javascript_()
    nt.assert_equal(data.get('application/javascript'), js)
    nt.assert_equal(metadata.get('application/javascript'), jsmd)
    
    dne = r['doesnotexist']
    nt.assert_equal(dne['status'], 'error')
    nt.assert_equal(dne['ename'], 'NameError')
    
    # back to text only
    ip.display_formatter.active_types = ['text/plain']
    
def test_user_expression():
    # enable all formatters
    ip.display_formatter.active_types = ip.display_formatter.format_types
    query = {
        'a' : '1 + 2',
        'b' : '1/0',
    }
    r = ip.user_expressions(query)
    import pprint
    pprint.pprint(r)
    nt.assert_equal(set(r.keys()), set(query.keys()))
    a = r['a']
    nt.assert_equal(set(['status', 'data', 'metadata']), set(a.keys()))
    nt.assert_equal(a['status'], 'ok')
    data = a['data']
    metadata = a['metadata']
    nt.assert_equal(data.get('text/plain'), '3')
    
    b = r['b']
    nt.assert_equal(b['status'], 'error')
    nt.assert_equal(b['ename'], 'ZeroDivisionError')
    
    # back to text only
    ip.display_formatter.active_types = ['text/plain']
    




class TestSyntaxErrorTransformer(unittest.TestCase):
    """Check that SyntaxError raised by an input transformer is handled by run_cell()"""

    class SyntaxErrorTransformer(InputTransformer):

        def push(self, line):
            pos = line.find('syntaxerror')
            if pos >= 0:
                e = SyntaxError('input contains "syntaxerror"')
                e.text = line
                e.offset = pos + 1
                raise e
            return line

        def reset(self):
            pass

    def setUp(self):
        self.transformer = TestSyntaxErrorTransformer.SyntaxErrorTransformer()
        ip.input_splitter.python_line_transforms.append(self.transformer)
        ip.input_transformer_manager.python_line_transforms.append(self.transformer)

    def tearDown(self):
        ip.input_splitter.python_line_transforms.remove(self.transformer)
        ip.input_transformer_manager.python_line_transforms.remove(self.transformer)

    def test_syntaxerror_input_transformer(self):
        with tt.AssertPrints('1234'):
            ip.run_cell('1234')
        with tt.AssertPrints('SyntaxError: invalid syntax'):
            ip.run_cell('1 2 3')   # plain python syntax error
        with tt.AssertPrints('SyntaxError: input contains "syntaxerror"'):
            ip.run_cell('2345  # syntaxerror')  # input transformer syntax error
        with tt.AssertPrints('3456'):
            ip.run_cell('3456')