from contextlib import contextmanager

import linecache

import os

import StringIO

import sys

import unittest

from test import test_support

import warning_tests

import warnings as original_warnings

sys.modules['_warnings'] = 0

del sys.modules['warnings']

import warnings as py_warnings

del sys.modules['_warnings']

del sys.modules['warnings']

import warnings as c_warnings

sys.modules['warnings'] = original_warnings

@contextmanager

def warnings_state(module):

    """Use a specific warnings implementation in warning_tests."""

    global __warningregistry__

    for to_clear in (sys, warning_tests):

        try:

            to_clear.__warningregistry__.clear()

        except AttributeError:

            pass

    try:

        __warningregistry__.clear()

    except NameError:

        pass

    original_warnings = warning_tests.warnings

    try:

        warning_tests.warnings = module

        yield

    finally:

        warning_tests.warnings = original_warnings

class BaseTest(unittest.TestCase):

    """Basic bookkeeping required for testing."""

    def setUp(self):

        # The __warningregistry__ needs to be in a pristine state for tests

        # to work properly.

        if '__warningregistry__' in globals():

            del globals()['__warningregistry__']

        if hasattr(warning_tests, '__warningregistry__'):

            del warning_tests.__warningregistry__

        if hasattr(sys, '__warningregistry__'):

            del sys.__warningregistry__

        # The 'warnings' module must be explicitly set so that the proper

        # interaction between _warnings and 'warnings' can be controlled.

        sys.modules['warnings'] = self.module

        super(BaseTest, self).setUp()

    def tearDown(self):

        sys.modules['warnings'] = original_warnings

        super(BaseTest, self).tearDown()

class FilterTests(object):

    """Testing the filtering functionality."""

    def test_error(self):

        with original_warnings.catch_warnings(module=self.module) as w:

            self.module.resetwarnings()

            self.module.filterwarnings("error", category=UserWarning)

            self.assertRaises(UserWarning, self.module.warn,

                                "FilterTests.test_error")

    def test_ignore(self):

        with original_warnings.catch_warnings(record=True,

                module=self.module) as w:

            self.module.resetwarnings()

            self.module.filterwarnings("ignore", category=UserWarning)

            self.module.warn("FilterTests.test_ignore", UserWarning)

            self.assertEquals(len(w), 0)

    def test_always(self):

        with original_warnings.catch_warnings(record=True,

                module=self.module) as w:

            self.module.resetwarnings()

            self.module.filterwarnings("always", category=UserWarning)

            message = "FilterTests.test_always"

            self.module.warn(message, UserWarning)

            self.assert_(message, w[-1].message)

            self.module.warn(message, UserWarning)

            self.assert_(w[-1].message, message)

    def test_default(self):

        with original_warnings.catch_warnings(record=True,

                module=self.module) as w:

            self.module.resetwarnings()

            self.module.filterwarnings("default", category=UserWarning)

            message = UserWarning("FilterTests.test_default")

            for x in xrange(2):

                self.module.warn(message, UserWarning)

                if x == 0:

                    self.assertEquals(w[-1].message, message)

                    del w[:]

                elif x == 1:

                    self.assertEquals(len(w), 0)

                else:

                    raise ValueError("loop variant unhandled")

    def test_module(self):

        with original_warnings.catch_warnings(record=True,

                module=self.module) as w:

            self.module.resetwarnings()

            self.module.filterwarnings("module", category=UserWarning)

            message = UserWarning("FilterTests.test_module")

            self.module.warn(message, UserWarning)

            self.assertEquals(w[-1].message, message)

            del w[:]

            self.module.warn(message, UserWarning)

            self.assertEquals(len(w), 0)

    def test_once(self):

        with original_warnings.catch_warnings(record=True,

                module=self.module) as w:

            self.module.resetwarnings()

            self.module.filterwarnings("once", category=UserWarning)

            message = UserWarning("FilterTests.test_once")

            self.module.warn_explicit(message, UserWarning, "test_warnings.py",

                                    42)

            self.assertEquals(w[-1].message, message)

            del w[:]

            self.module.warn_explicit(message, UserWarning, "test_warnings.py",

                                    13)

            self.assertEquals(len(w), 0)

            self.module.warn_explicit(message, UserWarning, "test_warnings2.py",

                                    42)

            self.assertEquals(len(w), 0)

    def test_inheritance(self):

        with original_warnings.catch_warnings(module=self.module) as w:

            self.module.resetwarnings()

            self.module.filterwarnings("error", category=Warning)

            self.assertRaises(UserWarning, self.module.warn,

                                "FilterTests.test_inheritance", UserWarning)

    def test_ordering(self):

        with original_warnings.catch_warnings(record=True,

                module=self.module) as w:

            self.module.resetwarnings()

            self.module.filterwarnings("ignore", category=UserWarning)

            self.module.filterwarnings("error", category=UserWarning,

                                        append=True)

            del w[:]

            try:

                self.module.warn("FilterTests.test_ordering", UserWarning)

            except UserWarning:

                self.fail("order handling for actions failed")

            self.assertEquals(len(w), 0)

    def test_filterwarnings(self):

        # Test filterwarnings().

        # Implicitly also tests resetwarnings().

        with original_warnings.catch_warnings(record=True,

                module=self.module) as w:

            self.module.filterwarnings("error", "", Warning, "", 0)

            self.assertRaises(UserWarning, self.module.warn, 'convert to error')

            self.module.resetwarnings()

            text = 'handle normally'

            self.module.warn(text)

            self.assertEqual(str(w[-1].message), text)

            self.assert_(w[-1].category is UserWarning)

            self.module.filterwarnings("ignore", "", Warning, "", 0)

            text = 'filtered out'

            self.module.warn(text)

            self.assertNotEqual(str(w[-1].message), text)

            self.module.resetwarnings()

            self.module.filterwarnings("error", "hex*", Warning, "", 0)

            self.assertRaises(UserWarning, self.module.warn, 'hex/oct')

            text = 'nonmatching text'

            self.module.warn(text)

            self.assertEqual(str(w[-1].message), text)

            self.assert_(w[-1].category is UserWarning)

class CFilterTests(BaseTest, FilterTests):

    module = c_warnings

class PyFilterTests(BaseTest, FilterTests):

    module = py_warnings

class WarnTests(unittest.TestCase):

    """Test warnings.warn() and warnings.warn_explicit()."""

    def test_message(self):

        with original_warnings.catch_warnings(record=True,

                module=self.module) as w:

            for i in range(4):

                text = 'multi %d' %i  # Different text on each call.

                self.module.warn(text)

                self.assertEqual(str(w[-1].message), text)

                self.assert_(w[-1].category is UserWarning)

    def test_filename(self):

        with warnings_state(self.module):

            with original_warnings.catch_warnings(record=True,

                    module=self.module) as w:

                warning_tests.inner("spam1")

                self.assertEqual(os.path.basename(w[-1].filename),

                                    "warning_tests.py")

                warning_tests.outer("spam2")

                self.assertEqual(os.path.basename(w[-1].filename),

                                    "warning_tests.py")

    def test_stacklevel(self):

        # Test stacklevel argument

        # make sure all messages are different, so the warning won't be skipped

        with warnings_state(self.module):

            with original_warnings.catch_warnings(record=True,

                    module=self.module) as w:

                warning_tests.inner("spam3", stacklevel=1)

                self.assertEqual(os.path.basename(w[-1].filename),

                                    "warning_tests.py")

                warning_tests.outer("spam4", stacklevel=1)

                self.assertEqual(os.path.basename(w[-1].filename),

                                    "warning_tests.py")

                warning_tests.inner("spam5", stacklevel=2)

                self.assertEqual(os.path.basename(w[-1].filename),

                                    "test_warnings.py")

                warning_tests.outer("spam6", stacklevel=2)

                self.assertEqual(os.path.basename(w[-1].filename),

                                    "warning_tests.py")

                warning_tests.outer("spam6.5", stacklevel=3)

                self.assertEqual(os.path.basename(w[-1].filename),

                                    "test_warnings.py")

                warning_tests.inner("spam7", stacklevel=9999)

                self.assertEqual(os.path.basename(w[-1].filename),

                                    "sys")

    def test_missing_filename_not_main(self):

        # If __file__ is not specified and __main__ is not the module name,

        # then __file__ should be set to the module name.

        filename = warning_tests.__file__

        try:

            del warning_tests.__file__

            with warnings_state(self.module):

                with original_warnings.catch_warnings(record=True,

                        module=self.module) as w:

                    warning_tests.inner("spam8", stacklevel=1)

                    self.assertEqual(w[-1].filename, warning_tests.__name__)

        finally:

            warning_tests.__file__ = filename

    def test_missing_filename_main_with_argv(self):

        # If __file__ is not specified and the caller is __main__ and sys.argv

        # exists, then use sys.argv[0] as the file.

        if not hasattr(sys, 'argv'):

            return

        filename = warning_tests.__file__

        module_name = warning_tests.__name__

        try:

            del warning_tests.__file__

            warning_tests.__name__ = '__main__'

            with warnings_state(self.module):

                with original_warnings.catch_warnings(record=True,

                        module=self.module) as w:

                    warning_tests.inner('spam9', stacklevel=1)

                    self.assertEqual(w[-1].filename, sys.argv[0])

        finally:

            warning_tests.__file__ = filename

            warning_tests.__name__ = module_name

    def test_missing_filename_main_without_argv(self):

        # If __file__ is not specified, the caller is __main__, and sys.argv

        # is not set, then '__main__' is the file name.

        filename = warning_tests.__file__

        module_name = warning_tests.__name__

        argv = sys.argv

        try:

            del warning_tests.__file__

            warning_tests.__name__ = '__main__'

            del sys.argv

            with warnings_state(self.module):

                with original_warnings.catch_warnings(record=True,

                        module=self.module) as w:

                    warning_tests.inner('spam10', stacklevel=1)

                    self.assertEqual(w[-1].filename, '__main__')

        finally:

            warning_tests.__file__ = filename

            warning_tests.__name__ = module_name

            sys.argv = argv

    def test_missing_filename_main_with_argv_empty_string(self):

        # If __file__ is not specified, the caller is __main__, and sys.argv[0]

        # is the empty string, then '__main__ is the file name.

        # Tests issue 2743.

        file_name = warning_tests.__file__

        module_name = warning_tests.__name__

        argv = sys.argv

        try:

            del warning_tests.__file__

            warning_tests.__name__ = '__main__'

            sys.argv = ['']

            with warnings_state(self.module):

                with original_warnings.catch_warnings(record=True,

                        module=self.module) as w:

                    warning_tests.inner('spam11', stacklevel=1)

                    self.assertEqual(w[-1].filename, '__main__')

        finally:

            warning_tests.__file__ = file_name

            warning_tests.__name__ = module_name

            sys.argv = argv

    def test_warn_explicit_type_errors(self):

        # warn_explicit() shoud error out gracefully if it is given objects

        # of the wrong types.

        # lineno is expected to be an integer.

        self.assertRaises(TypeError, self.module.warn_explicit,

                            None, UserWarning, None, None)

        # Either 'message' needs to be an instance of Warning or 'category'

        # needs to be a subclass.

        self.assertRaises(TypeError, self.module.warn_explicit,

                            None, None, None, 1)

        # 'registry' must be a dict or None.

        self.assertRaises((TypeError, AttributeError),

                            self.module.warn_explicit,

                            None, Warning, None, 1, registry=42)

class CWarnTests(BaseTest, WarnTests):

    module = c_warnings

class PyWarnTests(BaseTest, WarnTests):

    module = py_warnings

class WCmdLineTests(unittest.TestCase):

    def test_improper_input(self):

        # Uses the private _setoption() function to test the parsing

        # of command-line warning arguments

        with original_warnings.catch_warnings(module=self.module):

            self.assertRaises(self.module._OptionError,

                              self.module._setoption, '1:2:3:4:5:6')

            self.assertRaises(self.module._OptionError,

                              self.module._setoption, 'bogus::Warning')

            self.assertRaises(self.module._OptionError,

                              self.module._setoption, 'ignore:2::4:-5')

            self.module._setoption('error::Warning::0')

            self.assertRaises(UserWarning, self.module.warn, 'convert to error')

class CWCmdLineTests(BaseTest, WCmdLineTests):

    module = c_warnings

class PyWCmdLineTests(BaseTest, WCmdLineTests):

    module = py_warnings

class _WarningsTests(BaseTest):

    """Tests specific to the _warnings module."""

    module = c_warnings

    def test_filter(self):

        # Everything should function even if 'filters' is not in warnings.

        with original_warnings.catch_warnings(module=self.module) as w:

            self.module.filterwarnings("error", "", Warning, "", 0)

            self.assertRaises(UserWarning, self.module.warn,

                                'convert to error')

            del self.module.filters

            self.assertRaises(UserWarning, self.module.warn,

                                'convert to error')

    def test_onceregistry(self):

        # Replacing or removing the onceregistry should be okay.

        global __warningregistry__

        message = UserWarning('onceregistry test')

        try:

            original_registry = self.module.onceregistry

            __warningregistry__ = {}

            with original_warnings.catch_warnings(record=True,

                    module=self.module) as w:

                self.module.resetwarnings()

                self.module.filterwarnings("once", category=UserWarning)

                self.module.warn_explicit(message, UserWarning, "file", 42)

                self.failUnlessEqual(w[-1].message, message)

                del w[:]

                self.module.warn_explicit(message, UserWarning, "file", 42)

                self.assertEquals(len(w), 0)

                # Test the resetting of onceregistry.

                self.module.onceregistry = {}

                __warningregistry__ = {}

                self.module.warn('onceregistry test')

                self.failUnlessEqual(w[-1].message.args, message.args)

                # Removal of onceregistry is okay.

                del w[:]

                del self.module.onceregistry

                __warningregistry__ = {}

                self.module.warn_explicit(message, UserWarning, "file", 42)

                self.assertEquals(len(w), 0)

        finally:

            self.module.onceregistry = original_registry

    def test_showwarning_missing(self):

        # Test that showwarning() missing is okay.

        text = 'del showwarning test'

        with original_warnings.catch_warnings(module=self.module):

            self.module.filterwarnings("always", category=UserWarning)

            del self.module.showwarning

            with test_support.captured_output('stderr') as stream:

                self.module.warn(text)

                result = stream.getvalue()

        self.failUnless(text in result)

    def test_showwarning_not_callable(self):

        self.module.filterwarnings("always", category=UserWarning)

        old_showwarning = self.module.showwarning

        self.module.showwarning = 23

        try:

            self.assertRaises(TypeError, self.module.warn, "Warning!")

        finally:

            self.module.showwarning = old_showwarning

            self.module.resetwarnings()

    def test_show_warning_output(self):

        # With showarning() missing, make sure that output is okay.

        text = 'test show_warning'

        with original_warnings.catch_warnings(module=self.module):

            self.module.filterwarnings("always", category=UserWarning)

            del self.module.showwarning

            with test_support.captured_output('stderr') as stream:

                warning_tests.inner(text)

                result = stream.getvalue()

        self.failUnlessEqual(result.count('\n'), 2,

                             "Too many newlines in %r" % result)

        first_line, second_line = result.split('\n', 1)

        expected_file = os.path.splitext(warning_tests.__file__)[0] + '.py'

        first_line_parts = first_line.rsplit(':', 3)

        path, line, warning_class, message = first_line_parts

        line = int(line)

        self.failUnlessEqual(expected_file, path)

        self.failUnlessEqual(warning_class, ' ' + UserWarning.__name__)

        self.failUnlessEqual(message, ' ' + text)

        expected_line = '  ' + linecache.getline(path, line).strip() + '\n'

        assert expected_line

        self.failUnlessEqual(second_line, expected_line)

class WarningsDisplayTests(unittest.TestCase):

    """Test the displaying of warnings and the ability to overload functions

    related to displaying warnings."""

    def test_formatwarning(self):

        message = "msg"

        category = Warning

        file_name = os.path.splitext(warning_tests.__file__)[0] + '.py'

        line_num = 3

        file_line = linecache.getline(file_name, line_num).strip()

        format = "%s:%s: %s: %s\n  %s\n"

        expect = format % (file_name, line_num, category.__name__, message,

                            file_line)

        self.failUnlessEqual(expect, self.module.formatwarning(message,

                                                category, file_name, line_num))

        # Test the 'line' argument.

        file_line += " for the win!"

        expect = format % (file_name, line_num, category.__name__, message,

                            file_line)

        self.failUnlessEqual(expect, self.module.formatwarning(message,

                                    category, file_name, line_num, file_line))

    def test_showwarning(self):

        file_name = os.path.splitext(warning_tests.__file__)[0] + '.py'

        line_num = 3

        expected_file_line = linecache.getline(file_name, line_num).strip()

        message = 'msg'

        category = Warning

        file_object = StringIO.StringIO()

        expect = self.module.formatwarning(message, category, file_name,

                                            line_num)

        self.module.showwarning(message, category, file_name, line_num,

                                file_object)

        self.failUnlessEqual(file_object.getvalue(), expect)

        # Test 'line' argument.

        expected_file_line += "for the win!"

        expect = self.module.formatwarning(message, category, file_name,

                                            line_num, expected_file_line)

        file_object = StringIO.StringIO()

        self.module.showwarning(message, category, file_name, line_num,

                                file_object, expected_file_line)

        self.failUnlessEqual(expect, file_object.getvalue())

class CWarningsDisplayTests(BaseTest, WarningsDisplayTests):

    module = c_warnings

class PyWarningsDisplayTests(BaseTest, WarningsDisplayTests):

    module = py_warnings

class CatchWarningTests(BaseTest):

    """Test catch_warnings()."""

    def test_catch_warnings_restore(self):

        wmod = self.module

        orig_filters = wmod.filters

        orig_showwarning = wmod.showwarning

        # Ensure both showwarning and filters are restored when recording

        with wmod.catch_warnings(module=wmod, record=True):

            wmod.filters = wmod.showwarning = object()

        self.assert_(wmod.filters is orig_filters)

        self.assert_(wmod.showwarning is orig_showwarning)

        # Same test, but with recording disabled

        with wmod.catch_warnings(module=wmod, record=False):

            wmod.filters = wmod.showwarning = object()

        self.assert_(wmod.filters is orig_filters)