# test the invariant that

#   iff a==b then hash(a)==hash(b)

#

# Also test that hash implementations are inherited as expected

import unittest

from test import test_support

from collections import Hashable

class HashEqualityTestCase(unittest.TestCase):

    def same_hash(self, *objlist):

        # Hash each object given and fail if

        # the hash values are not all the same.

        hashed = map(hash, objlist)

        for h in hashed[1:]:

            if h != hashed[0]:

                self.fail("hashed values differ: %r" % (objlist,))

    def test_numeric_literals(self):

        self.same_hash(1, 1L, 1.0, 1.0+0.0j)

        self.same_hash(0, 0L, 0.0, 0.0+0.0j)

        self.same_hash(-1, -1L, -1.0, -1.0+0.0j)

        self.same_hash(-2, -2L, -2.0, -2.0+0.0j)

    def test_coerced_integers(self):

        self.same_hash(int(1), long(1), float(1), complex(1),

                       int('1'), float('1.0'))

        self.same_hash(int(-2**31), long(-2**31), float(-2**31))

        self.same_hash(int(1-2**31), long(1-2**31), float(1-2**31))

        self.same_hash(int(2**31-1), long(2**31-1), float(2**31-1))

        # for 64-bit platforms

        self.same_hash(int(2**31), long(2**31), float(2**31))

        self.same_hash(int(-2**63), long(-2**63), float(-2**63))

        self.same_hash(int(1-2**63), long(1-2**63))

        self.same_hash(int(2**63-1), long(2**63-1))

    def test_coerced_floats(self):

        self.same_hash(long(1.23e300), float(1.23e300))

        self.same_hash(float(0.5), complex(0.5, 0.0))

_default_hash = object.__hash__

class DefaultHash(object): pass

_FIXED_HASH_VALUE = 42

class FixedHash(object):

    def __hash__(self):

        return _FIXED_HASH_VALUE

class OnlyEquality(object):

    def __eq__(self, other):

        return self is other

    # Trick to suppress Py3k warning in 2.x

    __hash__ = None

del OnlyEquality.__hash__

class OnlyInequality(object):

    def __ne__(self, other):

        return self is not other

class OnlyCmp(object):

    def __cmp__(self, other):

        return cmp(id(self), id(other))

    # Trick to suppress Py3k warning in 2.x

    __hash__ = None

del OnlyCmp.__hash__

class InheritedHashWithEquality(FixedHash, OnlyEquality): pass

class InheritedHashWithInequality(FixedHash, OnlyInequality): pass

class InheritedHashWithCmp(FixedHash, OnlyCmp): pass

class NoHash(object):

    __hash__ = None

class HashInheritanceTestCase(unittest.TestCase):

    default_expected = [object(),

                        DefaultHash(),

                        OnlyEquality(),

                        OnlyInequality(),

                        OnlyCmp(),

                       ]

    fixed_expected = [FixedHash(),

                      InheritedHashWithEquality(),

                      InheritedHashWithInequality(),

                      InheritedHashWithCmp(),

                      ]

    error_expected = [NoHash()]

    def test_default_hash(self):

        for obj in self.default_expected:

            self.assertEqual(hash(obj), _default_hash(obj))

    def test_fixed_hash(self):

        for obj in self.fixed_expected:

            self.assertEqual(hash(obj), _FIXED_HASH_VALUE)

    def test_error_hash(self):

        for obj in self.error_expected:

            self.assertRaises(TypeError, hash, obj)

    def test_hashable(self):

        objects = (self.default_expected +

                   self.fixed_expected)

        for obj in objects:

            self.assert_(isinstance(obj, Hashable), repr(obj))

    def test_not_hashable(self):

        for obj in self.error_expected:

            self.assertFalse(isinstance(obj, Hashable), repr(obj))

def test_main():

    test_support.run_unittest(HashEqualityTestCase,

                              HashInheritanceTestCase)

if __name__ == "__main__":

    test_main()