cpython/Lib/test/test_inspect.py

import sys
import types
import unittest
import inspect
import datetime

from test.test_support import TESTFN, run_unittest

from test import inspect_fodder as mod
from test import inspect_fodder2 as mod2

# C module for test_findsource_binary
import unicodedata

# Functions tested in this suite:
# ismodule, isclass, ismethod, isfunction, istraceback, isframe, iscode,
# isbuiltin, isroutine, isgenerator, isgeneratorfunction, getmembers,
# getdoc, getfile, getmodule, getsourcefile, getcomments, getsource,
# getclasstree, getargspec, getargvalues, formatargspec, formatargvalues,
# currentframe, stack, trace, isdatadescriptor

# NOTE: There are some additional tests relating to interaction with
#       zipimport in the test_zipimport_support test module.

modfile = mod.__file__
if modfile.endswith(('c', 'o')):
    modfile = modfile[:-1]

import __builtin__

try:
    1/0
except:
    tb = sys.exc_traceback

git = mod.StupidGit()

class IsTestBase(unittest.TestCase):
    predicates = set([inspect.isbuiltin, inspect.isclass, inspect.iscode,
                      inspect.isframe, inspect.isfunction, inspect.ismethod,
                      inspect.ismodule, inspect.istraceback,
                      inspect.isgenerator, inspect.isgeneratorfunction])

    def istest(self, predicate, exp):
        obj = eval(exp)
        self.assertTrue(predicate(obj), '%s(%s)' % (predicate.__name__, exp))

        for other in self.predicates - set([predicate]):
            if predicate == inspect.isgeneratorfunction and\
               other == inspect.isfunction:
                continue
            self.assertFalse(other(obj), 'not %s(%s)' % (other.__name__, exp))

def generator_function_example(self):
    for i in xrange(2):
        yield i

class TestPredicates(IsTestBase):
    def test_sixteen(self):
        count = len(filter(lambda x:x.startswith('is'), dir(inspect)))
        # This test is here for remember you to update Doc/library/inspect.rst
        # which claims there are 16 such functions
        expected = 16
        err_msg = "There are %d (not %d) is* functions" % (count, expected)
        self.assertEqual(count, expected, err_msg)


    def test_excluding_predicates(self):
        self.istest(inspect.isbuiltin, 'sys.exit')
        self.istest(inspect.isbuiltin, '[].append')
        self.istest(inspect.iscode, 'mod.spam.func_code')
        self.istest(inspect.isframe, 'tb.tb_frame')
        self.istest(inspect.isfunction, 'mod.spam')
        self.istest(inspect.ismethod, 'mod.StupidGit.abuse')
        self.istest(inspect.ismethod, 'git.argue')
        self.istest(inspect.ismodule, 'mod')
        self.istest(inspect.istraceback, 'tb')
        self.istest(inspect.isdatadescriptor, '__builtin__.file.closed')
        self.istest(inspect.isdatadescriptor, '__builtin__.file.softspace')
        self.istest(inspect.isgenerator, '(x for x in xrange(2))')
        self.istest(inspect.isgeneratorfunction, 'generator_function_example')
        if hasattr(types, 'GetSetDescriptorType'):
            self.istest(inspect.isgetsetdescriptor,
                        'type(tb.tb_frame).f_locals')
        else:
            self.assertFalse(inspect.isgetsetdescriptor(type(tb.tb_frame).f_locals))
        if hasattr(types, 'MemberDescriptorType'):
            self.istest(inspect.ismemberdescriptor, 'datetime.timedelta.days')
        else:
            self.assertFalse(inspect.ismemberdescriptor(datetime.timedelta.days))

    def test_isroutine(self):
        self.assertTrue(inspect.isroutine(mod.spam))
        self.assertTrue(inspect.isroutine([].count))

    def test_isclass(self):
        self.istest(inspect.isclass, 'mod.StupidGit')
        self.assertTrue(inspect.isclass(list))

        class newstyle(object): pass
        self.assertTrue(inspect.isclass(newstyle))

        class CustomGetattr(object):
            def __getattr__(self, attr):
                return None
        self.assertFalse(inspect.isclass(CustomGetattr()))

    def test_get_slot_members(self):
        class C(object):
            __slots__ = ("a", "b")

        x = C()
        x.a = 42
        members = dict(inspect.getmembers(x))
        self.assertTrue('a' in members)
        self.assertTrue('b' not in members)

    def test_isabstract(self):
        from abc import ABCMeta, abstractmethod

        class AbstractClassExample(object):
            __metaclass__ = ABCMeta

            @abstractmethod
            def foo(self):
                pass

        class ClassExample(AbstractClassExample):
            def foo(self):
                pass

        a = ClassExample()

        # Test general behaviour.
        self.assertTrue(inspect.isabstract(AbstractClassExample))
        self.assertFalse(inspect.isabstract(ClassExample))
        self.assertFalse(inspect.isabstract(a))
        self.assertFalse(inspect.isabstract(int))
        self.assertFalse(inspect.isabstract(5))


class TestInterpreterStack(IsTestBase):
    def __init__(self, *args, **kwargs):
        unittest.TestCase.__init__(self, *args, **kwargs)

        git.abuse(7, 8, 9)

    def test_abuse_done(self):
        self.istest(inspect.istraceback, 'git.ex[2]')
        self.istest(inspect.isframe, 'mod.fr')

    def test_stack(self):
        self.assertTrue(len(mod.st) >= 5)
        self.assertEqual(mod.st[0][1:],
             (modfile, 16, 'eggs', ['    st = inspect.stack()\n'], 0))
        self.assertEqual(mod.st[1][1:],
             (modfile, 9, 'spam', ['    eggs(b + d, c + f)\n'], 0))
        self.assertEqual(mod.st[2][1:],
             (modfile, 43, 'argue', ['            spam(a, b, c)\n'], 0))
        self.assertEqual(mod.st[3][1:],
             (modfile, 39, 'abuse', ['        self.argue(a, b, c)\n'], 0))

    def test_trace(self):
        self.assertEqual(len(git.tr), 3)
        self.assertEqual(git.tr[0][1:], (modfile, 43, 'argue',
                                         ['            spam(a, b, c)\n'], 0))
        self.assertEqual(git.tr[1][1:], (modfile, 9, 'spam',
                                         ['    eggs(b + d, c + f)\n'], 0))
        self.assertEqual(git.tr[2][1:], (modfile, 18, 'eggs',
                                         ['    q = y / 0\n'], 0))

    def test_frame(self):
        args, varargs, varkw, locals = inspect.getargvalues(mod.fr)
        self.assertEqual(args, ['x', 'y'])
        self.assertEqual(varargs, None)
        self.assertEqual(varkw, None)
        self.assertEqual(locals, {'x': 11, 'p': 11, 'y': 14})
        self.assertEqual(inspect.formatargvalues(args, varargs, varkw, locals),
                         '(x=11, y=14)')

    def test_previous_frame(self):
        args, varargs, varkw, locals = inspect.getargvalues(mod.fr.f_back)
        self.assertEqual(args, ['a', 'b', 'c', 'd', ['e', ['f']]])
        self.assertEqual(varargs, 'g')
        self.assertEqual(varkw, 'h')
        self.assertEqual(inspect.formatargvalues(args, varargs, varkw, locals),
             '(a=7, b=8, c=9, d=3, (e=4, (f=5,)), *g=(), **h={})')

class GetSourceBase(unittest.TestCase):
    # Subclasses must override.
    fodderFile = None

    def __init__(self, *args, **kwargs):
        unittest.TestCase.__init__(self, *args, **kwargs)

        with open(inspect.getsourcefile(self.fodderFile)) as fp:
            self.source = fp.read()

    def sourcerange(self, top, bottom):
        lines = self.source.split("\n")
        return "\n".join(lines[top-1:bottom]) + "\n"

    def assertSourceEqual(self, obj, top, bottom):
        self.assertEqual(inspect.getsource(obj),
                         self.sourcerange(top, bottom))

class TestRetrievingSourceCode(GetSourceBase):
    fodderFile = mod

    def test_getclasses(self):
        classes = inspect.getmembers(mod, inspect.isclass)
        self.assertEqual(classes,
                         [('FesteringGob', mod.FesteringGob),
                          ('MalodorousPervert', mod.MalodorousPervert),
                          ('ParrotDroppings', mod.ParrotDroppings),
                          ('StupidGit', mod.StupidGit)])
        tree = inspect.getclasstree([cls[1] for cls in classes], 1)
        self.assertEqual(tree,
                         [(mod.ParrotDroppings, ()),
                          (mod.StupidGit, ()),
                          [(mod.MalodorousPervert, (mod.StupidGit,)),
                           [(mod.FesteringGob, (mod.MalodorousPervert,
                                                   mod.ParrotDroppings))
                            ]
                           ]
                          ])

    def test_getfunctions(self):
        functions = inspect.getmembers(mod, inspect.isfunction)
        self.assertEqual(functions, [('eggs', mod.eggs),
                                     ('spam', mod.spam)])

    def test_getdoc(self):
        self.assertEqual(inspect.getdoc(mod), 'A module docstring.')
        self.assertEqual(inspect.getdoc(mod.StupidGit),
                         'A longer,\n\nindented\n\ndocstring.')
        self.assertEqual(inspect.getdoc(git.abuse),
                         'Another\n\ndocstring\n\ncontaining\n\ntabs')

    def test_cleandoc(self):
        self.assertEqual(inspect.cleandoc('An\n    indented\n    docstring.'),
                         'An\nindented\ndocstring.')

    def test_getcomments(self):
        self.assertEqual(inspect.getcomments(mod), '# line 1\n')
        self.assertEqual(inspect.getcomments(mod.StupidGit), '# line 20\n')

    def test_getmodule(self):
        # Check actual module
        self.assertEqual(inspect.getmodule(mod), mod)
        # Check class (uses __module__ attribute)
        self.assertEqual(inspect.getmodule(mod.StupidGit), mod)
        # Check a method (no __module__ attribute, falls back to filename)
        self.assertEqual(inspect.getmodule(mod.StupidGit.abuse), mod)
        # Do it again (check the caching isn't broken)
        self.assertEqual(inspect.getmodule(mod.StupidGit.abuse), mod)
        # Check a builtin
        self.assertEqual(inspect.getmodule(str), sys.modules["__builtin__"])
        # Check filename override
        self.assertEqual(inspect.getmodule(None, modfile), mod)

    def test_getsource(self):
        self.assertSourceEqual(git.abuse, 29, 39)
        self.assertSourceEqual(mod.StupidGit, 21, 46)

    def test_getsourcefile(self):
        self.assertEqual(inspect.getsourcefile(mod.spam), modfile)
        self.assertEqual(inspect.getsourcefile(git.abuse), modfile)

    def test_getfile(self):
        self.assertEqual(inspect.getfile(mod.StupidGit), mod.__file__)

    def test_getmodule_recursion(self):
        from types import ModuleType
        name = '__inspect_dummy'
        m = sys.modules[name] = ModuleType(name)
        m.__file__ = "<string>" # hopefully not a real filename...
        m.__loader__ = "dummy"  # pretend the filename is understood by a loader
        exec "def x(): pass" in m.__dict__
        self.assertEqual(inspect.getsourcefile(m.x.func_code), '<string>')
        del sys.modules[name]
        inspect.getmodule(compile('a=10','','single'))

class TestDecorators(GetSourceBase):
    fodderFile = mod2

    def test_wrapped_decorator(self):
        self.assertSourceEqual(mod2.wrapped, 14, 17)

    def test_replacing_decorator(self):
        self.assertSourceEqual(mod2.gone, 9, 10)

class TestOneliners(GetSourceBase):
    fodderFile = mod2
    def test_oneline_lambda(self):
        # Test inspect.getsource with a one-line lambda function.
        self.assertSourceEqual(mod2.oll, 25, 25)

    def test_threeline_lambda(self):
        # Test inspect.getsource with a three-line lambda function,
        # where the second and third lines are _not_ indented.
        self.assertSourceEqual(mod2.tll, 28, 30)

    def test_twoline_indented_lambda(self):
        # Test inspect.getsource with a two-line lambda function,
        # where the second line _is_ indented.
        self.assertSourceEqual(mod2.tlli, 33, 34)

    def test_onelinefunc(self):
        # Test inspect.getsource with a regular one-line function.
        self.assertSourceEqual(mod2.onelinefunc, 37, 37)

    def test_manyargs(self):
        # Test inspect.getsource with a regular function where
        # the arguments are on two lines and _not_ indented and
        # the body on the second line with the last arguments.
        self.assertSourceEqual(mod2.manyargs, 40, 41)

    def test_twolinefunc(self):
        # Test inspect.getsource with a regular function where
        # the body is on two lines, following the argument list and
        # continued on the next line by a \\.
        self.assertSourceEqual(mod2.twolinefunc, 44, 45)

    def test_lambda_in_list(self):
        # Test inspect.getsource with a one-line lambda function
        # defined in a list, indented.
        self.assertSourceEqual(mod2.a[1], 49, 49)

    def test_anonymous(self):
        # Test inspect.getsource with a lambda function defined
        # as argument to another function.
        self.assertSourceEqual(mod2.anonymous, 55, 55)

class TestBuggyCases(GetSourceBase):
    fodderFile = mod2

    def test_with_comment(self):
        self.assertSourceEqual(mod2.with_comment, 58, 59)

    def test_multiline_sig(self):
        self.assertSourceEqual(mod2.multiline_sig[0], 63, 64)

    def test_nested_class(self):
        self.assertSourceEqual(mod2.func69().func71, 71, 72)

    def test_one_liner_followed_by_non_name(self):
        self.assertSourceEqual(mod2.func77, 77, 77)

    def test_one_liner_dedent_non_name(self):
        self.assertSourceEqual(mod2.cls82.func83, 83, 83)

    def test_with_comment_instead_of_docstring(self):
        self.assertSourceEqual(mod2.func88, 88, 90)

    def test_method_in_dynamic_class(self):
        self.assertSourceEqual(mod2.method_in_dynamic_class, 95, 97)

    @unittest.skipIf(
        not hasattr(unicodedata, '__file__') or
            unicodedata.__file__[-4:] in (".pyc", ".pyo"),
        "unicodedata is not an external binary module")
    def test_findsource_binary(self):
        self.assertRaises(IOError, inspect.getsource, unicodedata)
        self.assertRaises(IOError, inspect.findsource, unicodedata)

# Helper for testing classify_class_attrs.
def attrs_wo_objs(cls):
    return [t[:3] for t in inspect.classify_class_attrs(cls)]

class TestClassesAndFunctions(unittest.TestCase):
    def test_classic_mro(self):
        # Test classic-class method resolution order.
        class A:    pass
        class B(A): pass
        class C(A): pass
        class D(B, C): pass

        expected = (D, B, A, C)
        got = inspect.getmro(D)
        self.assertEqual(expected, got)

    def test_newstyle_mro(self):
        # The same w/ new-class MRO.
        class A(object):    pass
        class B(A): pass
        class C(A): pass
        class D(B, C): pass

        expected = (D, B, C, A, object)
        got = inspect.getmro(D)
        self.assertEqual(expected, got)

    def assertArgSpecEquals(self, routine, args_e, varargs_e = None,
                            varkw_e = None, defaults_e = None,
                            formatted = None):
        args, varargs, varkw, defaults = inspect.getargspec(routine)
        self.assertEqual(args, args_e)
        self.assertEqual(varargs, varargs_e)
        self.assertEqual(varkw, varkw_e)
        self.assertEqual(defaults, defaults_e)
        if formatted is not None:
            self.assertEqual(inspect.formatargspec(args, varargs, varkw, defaults),
                             formatted)

    def test_getargspec(self):
        self.assertArgSpecEquals(mod.eggs, ['x', 'y'], formatted = '(x, y)')

        self.assertArgSpecEquals(mod.spam,
                                 ['a', 'b', 'c', 'd', ['e', ['f']]],
                                 'g', 'h', (3, (4, (5,))),
                                 '(a, b, c, d=3, (e, (f,))=(4, (5,)), *g, **h)')

    def test_getargspec_method(self):
        class A(object):
            def m(self):
                pass
        self.assertArgSpecEquals(A.m, ['self'])

    def test_getargspec_sublistofone(self):
        def sublistOfOne((foo,)): return 1
        self.assertArgSpecEquals(sublistOfOne, [['foo']])

        def fakeSublistOfOne((foo)): return 1
        self.assertArgSpecEquals(fakeSublistOfOne, ['foo'])

    def test_classify_oldstyle(self):
        class A:
            def s(): pass
            s = staticmethod(s)

            def c(cls): pass
            c = classmethod(c)

            def getp(self): pass
            p = property(getp)

            def m(self): pass

            def m1(self): pass

            datablob = '1'

        attrs = attrs_wo_objs(A)
        self.assertTrue(('s', 'static method', A) in attrs, 'missing static method')
        self.assertTrue(('c', 'class method', A) in attrs, 'missing class method')
        self.assertTrue(('p', 'property', A) in attrs, 'missing property')
        self.assertTrue(('m', 'method', A) in attrs, 'missing plain method')
        self.assertTrue(('m1', 'method', A) in attrs, 'missing plain method')
        self.assertTrue(('datablob', 'data', A) in attrs, 'missing data')

        class B(A):
            def m(self): pass

        attrs = attrs_wo_objs(B)
        self.assertTrue(('s', 'static method', A) in attrs, 'missing static method')
        self.assertTrue(('c', 'class method', A) in attrs, 'missing class method')
        self.assertTrue(('p', 'property', A) in attrs, 'missing property')
        self.assertTrue(('m', 'method', B) in attrs, 'missing plain method')
        self.assertTrue(('m1', 'method', A) in attrs, 'missing plain method')
        self.assertTrue(('datablob', 'data', A) in attrs, 'missing data')


        class C(A):
            def m(self): pass
            def c(self): pass

        attrs = attrs_wo_objs(C)
        self.assertTrue(('s', 'static method', A) in attrs, 'missing static method')
        self.assertTrue(('c', 'method', C) in attrs, 'missing plain method')
        self.assertTrue(('p', 'property', A) in attrs, 'missing property')
        self.assertTrue(('m', 'method', C) in attrs, 'missing plain method')
        self.assertTrue(('m1', 'method', A) in attrs, 'missing plain method')
        self.assertTrue(('datablob', 'data', A) in attrs, 'missing data')

        class D(B, C):
            def m1(self): pass

        attrs = attrs_wo_objs(D)
        self.assertTrue(('s', 'static method', A) in attrs, 'missing static method')
        self.assertTrue(('c', 'class method', A) in attrs, 'missing class method')
        self.assertTrue(('p', 'property', A) in attrs, 'missing property')
        self.assertTrue(('m', 'method', B) in attrs, 'missing plain method')
        self.assertTrue(('m1', 'method', D) in attrs, 'missing plain method')
        self.assertTrue(('datablob', 'data', A) in attrs, 'missing data')

    # Repeat all that, but w/ new-style classes.
    def test_classify_newstyle(self):
        class A(object):

            def s(): pass
            s = staticmethod(s)

            def c(cls): pass
            c = classmethod(c)

            def getp(self): pass
            p = property(getp)

            def m(self): pass

            def m1(self): pass

            datablob = '1'

        attrs = attrs_wo_objs(A)
        self.assertTrue(('s', 'static method', A) in attrs, 'missing static method')
        self.assertTrue(('c', 'class method', A) in attrs, 'missing class method')
        self.assertTrue(('p', 'property', A) in attrs, 'missing property')
        self.assertTrue(('m', 'method', A) in attrs, 'missing plain method')
        self.assertTrue(('m1', 'method', A) in attrs, 'missing plain method')
        self.assertTrue(('datablob', 'data', A) in attrs, 'missing data')

        class B(A):

            def m(self): pass

        attrs = attrs_wo_objs(B)
        self.assertTrue(('s', 'static method', A) in attrs, 'missing static method')
        self.assertTrue(('c', 'class method', A) in attrs, 'missing class method')
        self.assertTrue(('p', 'property', A) in attrs, 'missing property')
        self.assertTrue(('m', 'method', B) in attrs, 'missing plain method')
        self.assertTrue(('m1', 'method', A) in attrs, 'missing plain method')
        self.assertTrue(('datablob', 'data', A) in attrs, 'missing data')


        class C(A):

            def m(self): pass
            def c(self): pass

        attrs = attrs_wo_objs(C)
        self.assertTrue(('s', 'static method', A) in attrs, 'missing static method')
        self.assertTrue(('c', 'method', C) in attrs, 'missing plain method')
        self.assertTrue(('p', 'property', A) in attrs, 'missing property')
        self.assertTrue(('m', 'method', C) in attrs, 'missing plain method')
        self.assertTrue(('m1', 'method', A) in attrs, 'missing plain method')
        self.assertTrue(('datablob', 'data', A) in attrs, 'missing data')

        class D(B, C):

            def m1(self): pass

        attrs = attrs_wo_objs(D)
        self.assertTrue(('s', 'static method', A) in attrs, 'missing static method')
        self.assertTrue(('c', 'method', C) in attrs, 'missing plain method')
        self.assertTrue(('p', 'property', A) in attrs, 'missing property')
        self.assertTrue(('m', 'method', B) in attrs, 'missing plain method')
        self.assertTrue(('m1', 'method', D) in attrs, 'missing plain method')
        self.assertTrue(('datablob', 'data', A) in attrs, 'missing data')

def test_main():
    run_unittest(TestDecorators, TestRetrievingSourceCode, TestOneliners,
                 TestBuggyCases,
                 TestInterpreterStack, TestClassesAndFunctions, TestPredicates)

if __name__ == "__main__":
    test_main()