IPython/core/tests/test_oinspect.py

"""Tests for the object inspection functionality.
"""
#-----------------------------------------------------------------------------
#  Copyright (C) 2010-2011 The IPython Development Team.
#
#  Distributed under the terms of the BSD License.
#
#  The full license is in the file COPYING.txt, distributed with this software.
#-----------------------------------------------------------------------------

#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
from __future__ import print_function

# Stdlib imports
import os
import re
import sys

# Third-party imports
import nose.tools as nt

# Our own imports
from .. import oinspect
from IPython.core.magic import (Magics, magics_class, line_magic,
                                cell_magic, line_cell_magic,
                                register_line_magic, register_cell_magic,
                                register_line_cell_magic)
from decorator import decorator
from IPython.testing.decorators import skipif
from IPython.testing.tools import AssertPrints
from IPython.utils.path import compress_user
from IPython.utils import py3compat


#-----------------------------------------------------------------------------
# Globals and constants
#-----------------------------------------------------------------------------

inspector = oinspect.Inspector()
ip = get_ipython()

#-----------------------------------------------------------------------------
# Local utilities
#-----------------------------------------------------------------------------

# WARNING: since this test checks the line number where a function is
# defined, if any code is inserted above, the following line will need to be
# updated.  Do NOT insert any whitespace between the next line and the function
# definition below.
THIS_LINE_NUMBER = 52  # Put here the actual number of this line
def test_find_source_lines():
    nt.assert_equal(oinspect.find_source_lines(test_find_source_lines), 
                    THIS_LINE_NUMBER+1)


# A couple of utilities to ensure these tests work the same from a source or a
# binary install
def pyfile(fname):
    return os.path.normcase(re.sub('.py[co]$', '.py', fname))


def match_pyfiles(f1, f2):
    nt.assert_equal(pyfile(f1), pyfile(f2))


def test_find_file():
    match_pyfiles(oinspect.find_file(test_find_file), os.path.abspath(__file__))


def test_find_file_decorated1():

    @decorator
    def noop1(f):
        def wrapper():
            return f(*a, **kw)
        return wrapper

    @noop1
    def f(x):
        "My docstring"
    
    match_pyfiles(oinspect.find_file(f), os.path.abspath(__file__))
    nt.assert_equal(f.__doc__, "My docstring")


def test_find_file_decorated2():

    @decorator
    def noop2(f, *a, **kw):
        return f(*a, **kw)

    @noop2
    @noop2
    @noop2
    def f(x):
        "My docstring 2"
    
    match_pyfiles(oinspect.find_file(f), os.path.abspath(__file__))
    nt.assert_equal(f.__doc__, "My docstring 2")
    

def test_find_file_magic():
    run = ip.find_line_magic('run')
    nt.assert_not_equal(oinspect.find_file(run), None)


# A few generic objects we can then inspect in the tests below

class Call(object):
    """This is the class docstring."""

    def __init__(self, x, y=1):
        """This is the constructor docstring."""

    def __call__(self, *a, **kw):
        """This is the call docstring."""

    def method(self, x, z=2):
        """Some method's docstring"""

class SimpleClass(object):
    def method(self, x, z=2):
        """Some method's docstring"""


class OldStyle:
    """An old-style class for testing."""
    pass


def f(x, y=2, *a, **kw):
    """A simple function."""


def g(y, z=3, *a, **kw):
    pass  # no docstring


@register_line_magic
def lmagic(line):
    "A line magic"


@register_cell_magic
def cmagic(line, cell):
    "A cell magic"


@register_line_cell_magic
def lcmagic(line, cell=None):
    "A line/cell magic"


@magics_class
class SimpleMagics(Magics):
    @line_magic
    def Clmagic(self, cline):
        "A class-based line magic"
        
    @cell_magic
    def Ccmagic(self, cline, ccell):
        "A class-based cell magic"
        
    @line_cell_magic
    def Clcmagic(self, cline, ccell=None):
        "A class-based line/cell magic"


class Awkward(object):
    def __getattr__(self, name):
        raise Exception(name)

class NoBoolCall:
    """
    callable with `__bool__` raising should still be inspect-able.
    """

    def __call__(self):
        """does nothing"""
        pass

    def __bool__(self):
        """just raise NotImplemented"""
        raise NotImplementedError('Must be implemented')


class SerialLiar(object):
    """Attribute accesses always get another copy of the same class.

    unittest.mock.call does something similar, but it's not ideal for testing
    as the failure mode is to eat all your RAM. This gives up after 10k levels.
    """
    def __init__(self, max_fibbing_twig, lies_told=0):
        if lies_told > 10000:
            raise RuntimeError('Nose too long, honesty is the best policy')
        self.max_fibbing_twig = max_fibbing_twig
        self.lies_told = lies_told
        max_fibbing_twig[0] = max(max_fibbing_twig[0], lies_told)

    def __getattr__(self, item):
        return SerialLiar(self.max_fibbing_twig, self.lies_told + 1)


def check_calltip(obj, name, call, docstring):
    """Generic check pattern all calltip tests will use"""
    info = inspector.info(obj, name)
    call_line, ds = oinspect.call_tip(info)
    nt.assert_equal(call_line, call)
    nt.assert_equal(ds, docstring)

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

def test_calltip_class():
    check_calltip(Call, 'Call', 'Call(x, y=1)', Call.__init__.__doc__)


def test_calltip_instance():
    c = Call(1)
    check_calltip(c, 'c', 'c(*a, **kw)', c.__call__.__doc__)


def test_calltip_method():
    c = Call(1)
    check_calltip(c.method, 'c.method', 'c.method(x, z=2)', c.method.__doc__)


def test_calltip_function():
    check_calltip(f, 'f', 'f(x, y=2, *a, **kw)', f.__doc__)


def test_calltip_function2():
    check_calltip(g, 'g', 'g(y, z=3, *a, **kw)', '<no docstring>')


@skipif(sys.version_info >= (3, 5))
def test_calltip_builtin():
    check_calltip(sum, 'sum', None, sum.__doc__)


def test_calltip_line_magic():
    check_calltip(lmagic, 'lmagic', 'lmagic(line)', "A line magic")

        
def test_calltip_cell_magic():
    check_calltip(cmagic, 'cmagic', 'cmagic(line, cell)', "A cell magic")

        
def test_calltip_line_cell_magic():
    check_calltip(lcmagic, 'lcmagic', 'lcmagic(line, cell=None)', 
                  "A line/cell magic")
        

def test_class_magics():
    cm = SimpleMagics(ip)
    ip.register_magics(cm)
    check_calltip(cm.Clmagic, 'Clmagic', 'Clmagic(cline)',
                  "A class-based line magic")
    check_calltip(cm.Ccmagic, 'Ccmagic', 'Ccmagic(cline, ccell)',
                  "A class-based cell magic")
    check_calltip(cm.Clcmagic, 'Clcmagic', 'Clcmagic(cline, ccell=None)',
                  "A class-based line/cell magic")
    

def test_info():
    "Check that Inspector.info fills out various fields as expected."
    i = inspector.info(Call, oname='Call')
    nt.assert_equal(i['type_name'], 'type')
    expted_class = str(type(type))  # <class 'type'> (Python 3) or <type 'type'>
    nt.assert_equal(i['base_class'], expted_class)
    nt.assert_equal(i['string_form'], "<class 'IPython.core.tests.test_oinspect.Call'>")
    fname = __file__
    if fname.endswith(".pyc"):
        fname = fname[:-1]
    # case-insensitive comparison needed on some filesystems
    # e.g. Windows:
    nt.assert_equal(i['file'].lower(), compress_user(fname).lower())
    nt.assert_equal(i['definition'], None)
    nt.assert_equal(i['docstring'], Call.__doc__)
    nt.assert_equal(i['source'], None)
    nt.assert_true(i['isclass'])
    nt.assert_equal(i['init_definition'], "Call(self, x, y=1)\n")
    nt.assert_equal(i['init_docstring'], Call.__init__.__doc__)

    i = inspector.info(Call, detail_level=1)
    nt.assert_not_equal(i['source'], None)
    nt.assert_equal(i['docstring'], None)

    c = Call(1)
    c.__doc__ = "Modified instance docstring"
    i = inspector.info(c)
    nt.assert_equal(i['type_name'], 'Call')
    nt.assert_equal(i['docstring'], "Modified instance docstring")
    nt.assert_equal(i['class_docstring'], Call.__doc__)
    nt.assert_equal(i['init_docstring'], Call.__init__.__doc__)
    nt.assert_equal(i['call_docstring'], Call.__call__.__doc__)

    # Test old-style classes, which for example may not have an __init__ method.
    if not py3compat.PY3:
        i = inspector.info(OldStyle)
        nt.assert_equal(i['type_name'], 'classobj')

        i = inspector.info(OldStyle())
        nt.assert_equal(i['type_name'], 'instance')
        nt.assert_equal(i['docstring'], OldStyle.__doc__)

def test_info_awkward():
    # Just test that this doesn't throw an error.
    i = inspector.info(Awkward())

def test_bool_raise():
    inspector.info(NoBoolCall())

def test_info_serialliar():
    fib_tracker = [0]
    i = inspector.info(SerialLiar(fib_tracker))

    # Nested attribute access should be cut off at 100 levels deep to avoid
    # infinite loops: https://github.com/ipython/ipython/issues/9122
    nt.assert_less(fib_tracker[0], 9000)

def test_calldef_none():
    # We should ignore __call__ for all of these.
    for obj in [f, SimpleClass().method, any, str.upper]:
        print(obj)
        i = inspector.info(obj)
        nt.assert_is(i['call_def'], None)

if py3compat.PY3:
    exec("def f_kwarg(pos, *, kwonly): pass")

@skipif(not py3compat.PY3)
def test_definition_kwonlyargs():
    i = inspector.info(f_kwarg, oname='f_kwarg')  # analysis:ignore
    nt.assert_equal(i['definition'], "f_kwarg(pos, *, kwonly)\n")

def test_getdoc():
    class A(object):
        """standard docstring"""
        pass
    
    class B(object):
        """standard docstring"""
        def getdoc(self):
            return "custom docstring"
    
    class C(object):
        """standard docstring"""
        def getdoc(self):
            return None
    
    a = A()
    b = B()
    c = C()
    
    nt.assert_equal(oinspect.getdoc(a), "standard docstring")
    nt.assert_equal(oinspect.getdoc(b), "custom docstring")
    nt.assert_equal(oinspect.getdoc(c), "standard docstring")


def test_empty_property_has_no_source():
    i = inspector.info(property(), detail_level=1)
    nt.assert_is(i['source'], None)


def test_property_sources():
    import zlib

    class A(object):
        @property
        def foo(self):
            return 'bar'

        foo = foo.setter(lambda self, v: setattr(self, 'bar', v))

        id = property(id)
        compress = property(zlib.compress)

    i = inspector.info(A.foo, detail_level=1)
    nt.assert_in('def foo(self):', i['source'])
    nt.assert_in('lambda self, v:', i['source'])

    i = inspector.info(A.id, detail_level=1)
    nt.assert_in('fget = <function id>', i['source'])

    i = inspector.info(A.compress, detail_level=1)
    nt.assert_in('fget = <function zlib.compress>', i['source'])


def test_property_docstring_is_in_info_for_detail_level_0():
    class A(object):
        @property
        def foobar():
            """This is `foobar` property."""
            pass

    ip.user_ns['a_obj'] = A()
    nt.assert_equals(
        'This is `foobar` property.',
        ip.object_inspect('a_obj.foobar', detail_level=0)['docstring'])

    ip.user_ns['a_cls'] = A
    nt.assert_equals(
        'This is `foobar` property.',
        ip.object_inspect('a_cls.foobar', detail_level=0)['docstring'])


def test_pdef():
    # See gh-1914
    def foo(): pass
    inspector.pdef(foo, 'foo')

def test_pinfo_nonascii():
    # See gh-1177
    from . import nonascii2
    ip.user_ns['nonascii2'] = nonascii2
    ip._inspect('pinfo', 'nonascii2', detail_level=1)

def test_pinfo_magic():
    with AssertPrints('Docstring:'):
        ip._inspect('pinfo', 'lsmagic', detail_level=0)

    with AssertPrints('Source:'):
        ip._inspect('pinfo', 'lsmagic', detail_level=1)