# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.

"""
Tests for Twisted's deprecation framework, L{twisted.python.deprecate}.
"""

from __future__ import division, absolute_import

import sys, types, warnings
from os.path import normcase
from warnings import simplefilter, catch_warnings
try:
from importlib import invalidate_caches
except ImportError:
invalidate_caches = None

from twisted.python import deprecate
from twisted.python.deprecate import _getDeprecationWarningString
from twisted.python.deprecate import DEPRECATION_WARNING_FORMAT
from twisted.python.deprecate import (
getDeprecationWarningString,
deprecated, _appendToDocstring, _getDeprecationDocstring,
_fullyQualifiedName as fullyQualifiedName)

from twisted.python.versions import Version
from twisted.python.filepath import FilePath

from twisted.python.test import deprecatedattributes
from twisted.python.test.modules_helpers import TwistedModulesMixin

from twisted.trial.unittest import SynchronousTestCase

# Note that various tests in this module require manual encoding of paths to
# utf-8. This can be fixed once FilePath supports Unicode; see #2366, #4736,
# #5203.


class _MockDeprecatedAttribute(object):
"""
Mock of L{twisted.python.deprecate._DeprecatedAttribute}.

@ivar value: The value of the attribute.
"""
def __init__(self, value):
self.value = value


def get(self):
"""
Get a known value.
"""
return self.value



class ModuleProxyTests(SynchronousTestCase):
"""
Tests for L{twisted.python.deprecate._ModuleProxy}, which proxies
access to module-level attributes, intercepting access to deprecated
attributes and passing through access to normal attributes.
"""
def _makeProxy(self, **attrs):
"""
Create a temporary module proxy object.

@param **kw: Attributes to initialise on the temporary module object

@rtype: L{twistd.python.deprecate._ModuleProxy}
"""
mod = types.ModuleType('foo')
for key, value in attrs.items():
setattr(mod, key, value)
return deprecate._ModuleProxy(mod)


def test_getattrPassthrough(self):
"""
Getting a normal attribute on a L{twisted.python.deprecate._ModuleProxy}
retrieves the underlying attribute's value, and raises C{AttributeError}
if a non-existant attribute is accessed.
"""
proxy = self._makeProxy(SOME_ATTRIBUTE='hello')
self.assertIdentical(proxy.SOME_ATTRIBUTE, 'hello')
self.assertRaises(AttributeError, getattr, proxy, 'DOES_NOT_EXIST')


def test_getattrIntercept(self):
"""
Getting an attribute marked as being deprecated on
L{twisted.python.deprecate._ModuleProxy} results in calling the
deprecated wrapper's C{get} method.
"""
proxy = self._makeProxy()
_deprecatedAttributes = object.__getattribute__(
proxy, '_deprecatedAttributes')
_deprecatedAttributes['foo'] = _MockDeprecatedAttribute(42)
self.assertEqual(proxy.foo, 42)


def test_privateAttributes(self):
"""
Private attributes of L{twisted.python.deprecate._ModuleProxy} are
inaccessible when regular attribute access is used.
"""
proxy = self._makeProxy()
self.assertRaises(AttributeError, getattr, proxy, '_module')
self.assertRaises(
AttributeError, getattr, proxy, '_deprecatedAttributes')


def test_setattr(self):
"""
Setting attributes on L{twisted.python.deprecate._ModuleProxy} proxies
them through to the wrapped module.
"""
proxy = self._makeProxy()
proxy._module = 1
self.assertNotEquals(object.__getattribute__(proxy, '_module'), 1)
self.assertEqual(proxy._module, 1)


def test_repr(self):
"""
L{twisted.python.deprecated._ModuleProxy.__repr__} produces a string
containing the proxy type and a representation of the wrapped module
object.
"""
proxy = self._makeProxy()
realModule = object.__getattribute__(proxy, '_module')
self.assertEqual(
repr(proxy), '<%s module=%r>' % (type(proxy).__name__, realModule))



class DeprecatedAttributeTests(SynchronousTestCase):
"""
Tests for L{twisted.python.deprecate._DeprecatedAttribute} and
L{twisted.python.deprecate.deprecatedModuleAttribute}, which issue
warnings for deprecated module-level attributes.
"""
def setUp(self):
self.version = deprecatedattributes.version
self.message = deprecatedattributes.message
self._testModuleName = __name__ + '.foo'


def _getWarningString(self, attr):
"""
Create the warning string used by deprecated attributes.
"""
return _getDeprecationWarningString(
deprecatedattributes.__name__ + '.' + attr,
deprecatedattributes.version,
DEPRECATION_WARNING_FORMAT + ': ' + deprecatedattributes.message)


def test_deprecatedAttributeHelper(self):
"""
L{twisted.python.deprecate._DeprecatedAttribute} correctly sets its
__name__ to match that of the deprecated attribute and emits a warning
when the original attribute value is accessed.
"""
name = 'ANOTHER_DEPRECATED_ATTRIBUTE'
setattr(deprecatedattributes, name, 42)
attr = deprecate._DeprecatedAttribute(
deprecatedattributes, name, self.version, self.message)

self.assertEqual(attr.__name__, name)

# Since we're accessing the value getter directly, as opposed to via
# the module proxy, we need to match the warning's stack level.
def addStackLevel():
attr.get()

# Access the deprecated attribute.
addStackLevel()
warningsShown = self.flushWarnings([
self.test_deprecatedAttributeHelper])
self.assertIdentical(warningsShown[0]['category'], DeprecationWarning)
self.assertEqual(
warningsShown[0]['message'],
self._getWarningString(name))
self.assertEqual(len(warningsShown), 1)


def test_deprecatedAttribute(self):
"""
L{twisted.python.deprecate.deprecatedModuleAttribute} wraps a
module-level attribute in an object that emits a deprecation warning
when it is accessed the first time only, while leaving other unrelated
attributes alone.
"""
# Accessing non-deprecated attributes does not issue a warning.
deprecatedattributes.ANOTHER_ATTRIBUTE
warningsShown = self.flushWarnings([self.test_deprecatedAttribute])
self.assertEqual(len(warningsShown), 0)

name = 'DEPRECATED_ATTRIBUTE'

# Access the deprecated attribute. This uses getattr to avoid repeating
# the attribute name.
getattr(deprecatedattributes, name)

warningsShown = self.flushWarnings([self.test_deprecatedAttribute])
self.assertEqual(len(warningsShown), 1)
self.assertIdentical(warningsShown[0]['category'], DeprecationWarning)
self.assertEqual(
warningsShown[0]['message'],
self._getWarningString(name))


def test_wrappedModule(self):
"""
Deprecating an attribute in a module replaces and wraps that module
instance, in C{sys.modules}, with a
L{twisted.python.deprecate._ModuleProxy} instance but only if it hasn't
already been wrapped.
"""
sys.modules[self._testModuleName] = mod = types.ModuleType('foo')
self.addCleanup(sys.modules.pop, self._testModuleName)

setattr(mod, 'first', 1)
setattr(mod, 'second', 2)

deprecate.deprecatedModuleAttribute(
Version('Twisted', 8, 0, 0),
'message',
self._testModuleName,
'first')

proxy = sys.modules[self._testModuleName]
self.assertNotEqual(proxy, mod)

deprecate.deprecatedModuleAttribute(
Version('Twisted', 8, 0, 0),
'message',
self._testModuleName,
'second')

self.assertIdentical(proxy, sys.modules[self._testModuleName])



class ImportedModuleAttributeTests(TwistedModulesMixin, SynchronousTestCase):
"""
Tests for L{deprecatedModuleAttribute} which involve loading a module via
'import'.
"""

_packageInit = """\
from twisted.python.deprecate import deprecatedModuleAttribute
from twisted.python.versions import Version

deprecatedModuleAttribute(
Version('Package', 1, 2, 3), 'message', __name__, 'module')
"""


def pathEntryTree(self, tree):
"""
Create some files in a hierarchy, based on a dictionary describing those
files. The resulting hierarchy will be placed onto sys.path for the
duration of the test.

@param tree: A dictionary representing a directory structure. Keys are
strings, representing filenames, dictionary values represent
directories, string values represent file contents.

@return: another dictionary similar to the input, with file content
strings replaced with L{FilePath} objects pointing at where those
contents are now stored.
"""
def makeSomeFiles(pathobj, dirdict):
pathdict = {}
for (key, value) in dirdict.items():
child = pathobj.child(key)
if isinstance(value, bytes):
pathdict[key] = child
child.setContent(value)
elif isinstance(value, dict):
child.createDirectory()
pathdict[key] = makeSomeFiles(child, value)
else:
raise ValueError("only strings and dicts allowed as values")
return pathdict
base = FilePath(self.mktemp().encode("utf-8"))
base.makedirs()

result = makeSomeFiles(base, tree)
# On Python 3, sys.path cannot include byte paths:
self.replaceSysPath([base.path.decode("utf-8")] + sys.path)
self.replaceSysModules(sys.modules.copy())
return result


def simpleModuleEntry(self):
"""
Add a sample module and package to the path, returning a L{FilePath}
pointing at the module which will be loadable as C{package.module}.
"""
paths = self.pathEntryTree(
{b"package": {b"__init__.py": self._packageInit.encode("utf-8"),
b"module.py": b""}})
return paths[b'package'][b'module.py']


def checkOneWarning(self, modulePath):
"""
Verification logic for L{test_deprecatedModule}.
"""
from package import module
self.assertEqual(FilePath(module.__file__.encode("utf-8")),
modulePath)
emitted = self.flushWarnings([self.checkOneWarning])
self.assertEqual(len(emitted), 1)
self.assertEqual(emitted[0]['message'],
'package.module was deprecated in Package 1.2.3: '
'message')
self.assertEqual(emitted[0]['category'], DeprecationWarning)


def test_deprecatedModule(self):
"""
If L{deprecatedModuleAttribute} is used to deprecate a module attribute
of a package, only one deprecation warning is emitted when the
deprecated module is imported.
"""
self.checkOneWarning(self.simpleModuleEntry())


def test_deprecatedModuleMultipleTimes(self):
"""
If L{deprecatedModuleAttribute} is used to deprecate a module attribute
of a package, only one deprecation warning is emitted when the
deprecated module is subsequently imported.
"""
mp = self.simpleModuleEntry()
# The first time, the code needs to be loaded.
self.checkOneWarning(mp)
# The second time, things are slightly different; the object's already
# in the namespace.
self.checkOneWarning(mp)
# The third and fourth times, things things should all be exactly the
# same, but this is a sanity check to make sure the implementation isn't
# special casing the second time. Also, putting these cases into a loop
# means that the stack will be identical, to make sure that the
# implementation doesn't rely too much on stack-crawling.
for x in range(2):
self.checkOneWarning(mp)



class WarnAboutFunctionTests(SynchronousTestCase):
"""
Tests for L{twisted.python.deprecate.warnAboutFunction} which allows the
callers of a function to issue a C{DeprecationWarning} about that function.
"""
def setUp(self):
"""
Create a file that will have known line numbers when emitting warnings.
"""
self.package = FilePath(self.mktemp().encode("utf-8")
).child(b'twisted_private_helper')
self.package.makedirs()
self.package.child(b'__init__.py').setContent(b'')
self.package.child(b'module.py').setContent(b'''
"A module string"

from twisted.python import deprecate

def testFunction():
"A doc string"
a = 1 + 2
return a

def callTestFunction():
b = testFunction()
if b == 3:
deprecate.warnAboutFunction(testFunction, "A Warning String")
''')
# Python 3 doesn't accept bytes in sys.path:
packagePath = self.package.parent().path.decode("utf-8")
sys.path.insert(0, packagePath)
self.addCleanup(sys.path.remove, packagePath)

modules = sys.modules.copy()
self.addCleanup(
lambda: (sys.modules.clear(), sys.modules.update(modules)))


def test_warning(self):
"""
L{deprecate.warnAboutFunction} emits a warning the file and line number
of which point to the beginning of the implementation of the function
passed to it.
"""
def aFunc():
pass
deprecate.warnAboutFunction(aFunc, 'A Warning Message')
warningsShown = self.flushWarnings()
filename = __file__
if filename.lower().endswith('.pyc'):
filename = filename[:-1]
self.assertSamePath(
FilePath(warningsShown[0]["filename"]), FilePath(filename))
self.assertEqual(warningsShown[0]["message"], "A Warning Message")


def test_warningLineNumber(self):
"""
L{deprecate.warnAboutFunction} emits a C{DeprecationWarning} with the
number of a line within the implementation of the function passed to it.
"""
from twisted_private_helper import module
module.callTestFunction()
warningsShown = self.flushWarnings()
self.assertSamePath(
FilePath(warningsShown[0]["filename"].encode("utf-8")),
self.package.sibling(b'twisted_private_helper').child(b'module.py'))
# Line number 9 is the last line in the testFunction in the helper
# module.
self.assertEqual(warningsShown[0]["lineno"], 9)
self.assertEqual(warningsShown[0]["message"], "A Warning String")
self.assertEqual(len(warningsShown), 1)


def assertSamePath(self, first, second):
"""
Assert that the two paths are the same, considering case normalization
appropriate for the current platform.

@type first: L{FilePath}
@type second: L{FilePath}

@raise C{self.failureType}: If the paths are not the same.
"""
self.assertTrue(
normcase(first.path) == normcase(second.path),
"%r != %r" % (first, second))


def test_renamedFile(self):
"""
Even if the implementation of a deprecated function is moved around on
the filesystem, the line number in the warning emitted by
L{deprecate.warnAboutFunction} points to a line in the implementation of
the deprecated function.
"""
from twisted_private_helper import module
# Clean up the state resulting from that import; we're not going to use
# this module, so it should go away.
del sys.modules['twisted_private_helper']
del sys.modules[module.__name__]

# Rename the source directory
self.package.moveTo(self.package.sibling(b'twisted_renamed_helper'))

# Make sure importlib notices we've changed importable packages:
if invalidate_caches:
invalidate_caches()

# Import the newly renamed version
from twisted_renamed_helper import module
self.addCleanup(sys.modules.pop, 'twisted_renamed_helper')
self.addCleanup(sys.modules.pop, module.__name__)

module.callTestFunction()
warningsShown = self.flushWarnings()
warnedPath = FilePath(warningsShown[0]["filename"].encode("utf-8"))
expectedPath = self.package.sibling(
b'twisted_renamed_helper').child(b'module.py')
self.assertSamePath(warnedPath, expectedPath)
self.assertEqual(warningsShown[0]["lineno"], 9)
self.assertEqual(warningsShown[0]["message"], "A Warning String")
self.assertEqual(len(warningsShown), 1)


def test_filteredWarning(self):
"""
L{deprecate.warnAboutFunction} emits a warning that will be filtered if
L{warnings.filterwarning} is called with the module name of the
deprecated function.
"""
# Clean up anything *else* that might spuriously filter out the warning,
# such as the "always" simplefilter set up by unittest._collectWarnings.
# We'll also rely on trial to restore the original filters afterwards.
del warnings.filters[:]

warnings.filterwarnings(
action="ignore", module="twisted_private_helper")

from twisted_private_helper import module
module.callTestFunction()

warningsShown = self.flushWarnings()
self.assertEqual(len(warningsShown), 0)


def test_filteredOnceWarning(self):
"""
L{deprecate.warnAboutFunction} emits a warning that will be filtered
once if L{warnings.filterwarning} is called with the module name of the
deprecated function and an action of once.
"""
# Clean up anything *else* that might spuriously filter out the warning,
# such as the "always" simplefilter set up by unittest._collectWarnings.
# We'll also rely on trial to restore the original filters afterwards.
del warnings.filters[:]

warnings.filterwarnings(
action="module", module="twisted_private_helper")

from twisted_private_helper import module
module.callTestFunction()
module.callTestFunction()

warningsShown = self.flushWarnings()
self.assertEqual(len(warningsShown), 1)
message = warningsShown[0]['message']
category = warningsShown[0]['category']
filename = warningsShown[0]['filename']
lineno = warningsShown[0]['lineno']
msg = warnings.formatwarning(message, category, filename, lineno)
self.assertTrue(
msg.endswith("module.py:9: DeprecationWarning: A Warning String\n"
" return a\n"),
"Unexpected warning string: %r" % (msg,))


def dummyCallable():
"""
Do nothing.

This is used to test the deprecation decorators.
"""



def dummyReplacementMethod():
"""
Do nothing.

This is used to test the replacement parameter to L{deprecated}.
"""



class TestDeprecationWarnings(SynchronousTestCase):
def test_getDeprecationWarningString(self):
"""
L{getDeprecationWarningString} returns a string that tells us that a
callable was deprecated at a certain released version of Twisted.
"""
version = Version('Twisted', 8, 0, 0)
self.assertEqual(
getDeprecationWarningString(self.test_getDeprecationWarningString,
version),
"%s.TestDeprecationWarnings.test_getDeprecationWarningString "
"was deprecated in Twisted 8.0.0" % (__name__,))


def test_getDeprecationWarningStringWithFormat(self):
"""
L{getDeprecationWarningString} returns a string that tells us that a
callable was deprecated at a certain released version of Twisted, with
a message containing additional information about the deprecation.
"""
version = Version('Twisted', 8, 0, 0)
format = DEPRECATION_WARNING_FORMAT + ': This is a message'
self.assertEqual(
getDeprecationWarningString(self.test_getDeprecationWarningString,
version, format),
'%s.TestDeprecationWarnings.test_getDeprecationWarningString was '
'deprecated in Twisted 8.0.0: This is a message' % (__name__,))


def test_deprecateEmitsWarning(self):
"""
Decorating a callable with L{deprecated} emits a warning.
"""
version = Version('Twisted', 8, 0, 0)
dummy = deprecated(version)(dummyCallable)
def addStackLevel():
dummy()
with catch_warnings(record=True) as caught:
simplefilter("always")
addStackLevel()
self.assertEqual(caught[0].category, DeprecationWarning)
self.assertEqual(str(caught[0].message), getDeprecationWarningString(dummyCallable, version))
# rstrip in case .pyc/.pyo
self.assertEqual(caught[0].filename.rstrip('co'), __file__.rstrip('co'))


def test_deprecatedPreservesName(self):
"""
The decorated function has the same name as the original.
"""
version = Version('Twisted', 8, 0, 0)
dummy = deprecated(version)(dummyCallable)
self.assertEqual(dummyCallable.__name__, dummy.__name__)
self.assertEqual(fullyQualifiedName(dummyCallable),
fullyQualifiedName(dummy))


def test_getDeprecationDocstring(self):
"""
L{_getDeprecationDocstring} returns a note about the deprecation to go
into a docstring.
"""
version = Version('Twisted', 8, 0, 0)
self.assertEqual(
"Deprecated in Twisted 8.0.0.",
_getDeprecationDocstring(version, ''))


def test_deprecatedUpdatesDocstring(self):
"""
The docstring of the deprecated function is appended with information
about the deprecation.
"""

def localDummyCallable():
"""
Do nothing.

This is used to test the deprecation decorators.
"""

version = Version('Twisted', 8, 0, 0)
dummy = deprecated(version)(localDummyCallable)

_appendToDocstring(
localDummyCallable,
_getDeprecationDocstring(version, ''))

self.assertEqual(localDummyCallable.__doc__, dummy.__doc__)


def test_versionMetadata(self):
"""
Deprecating a function adds version information to the decorated
version of that function.
"""
version = Version('Twisted', 8, 0, 0)
dummy = deprecated(version)(dummyCallable)
self.assertEqual(version, dummy.deprecatedVersion)


def test_getDeprecationWarningStringReplacement(self):
"""
L{getDeprecationWarningString} takes an additional replacement parameter
that can be used to add information to the deprecation. If the
replacement parameter is a string, it will be interpolated directly into
the result.
"""
version = Version('Twisted', 8, 0, 0)
warningString = getDeprecationWarningString(
self.test_getDeprecationWarningString, version,
replacement="something.foobar")
self.assertEqual(
warningString,
"%s was deprecated in Twisted 8.0.0; please use something.foobar "
"instead" % (
fullyQualifiedName(self.test_getDeprecationWarningString),))


def test_getDeprecationWarningStringReplacementWithCallable(self):
"""
L{getDeprecationWarningString} takes an additional replacement parameter
that can be used to add information to the deprecation. If the
replacement parameter is a callable, its fully qualified name will be
interpolated into the result.
"""
version = Version('Twisted', 8, 0, 0)
warningString = getDeprecationWarningString(
self.test_getDeprecationWarningString, version,
replacement=dummyReplacementMethod)
self.assertEqual(
warningString,
"%s was deprecated in Twisted 8.0.0; please use "
"%s.dummyReplacementMethod instead" % (
fullyQualifiedName(self.test_getDeprecationWarningString),
__name__))


def test_deprecatedReplacement(self):
"""
L{deprecated} takes an additional replacement parameter that can be used
to indicate the new, non-deprecated method developers should use. If
the replacement parameter is a string, it will be interpolated directly
into the warning message.
"""
version = Version('Twisted', 8, 0, 0)
dummy = deprecated(version, "something.foobar")(dummyCallable)
self.assertEqual(dummy.__doc__,
"\n"
" Do nothing.\n\n"
" This is used to test the deprecation decorators.\n\n"
" Deprecated in Twisted 8.0.0; please use "
"something.foobar"
" instead.\n"
" ")


def test_deprecatedReplacementWithCallable(self):
"""
L{deprecated} takes an additional replacement parameter that can be used
to indicate the new, non-deprecated method developers should use. If
the replacement parameter is a callable, its fully qualified name will
be interpolated into the warning message.
"""
version = Version('Twisted', 8, 0, 0)
decorator = deprecated(version, replacement=dummyReplacementMethod)
dummy = decorator(dummyCallable)
self.assertEqual(dummy.__doc__,
"\n"
" Do nothing.\n\n"
" This is used to test the deprecation decorators.\n\n"
" Deprecated in Twisted 8.0.0; please use "
"%s.dummyReplacementMethod instead.\n"
" " % (__name__,))



class TestAppendToDocstring(SynchronousTestCase):
"""
Test the _appendToDocstring function.

_appendToDocstring is used to add text to a docstring.
"""

def test_appendToEmptyDocstring(self):
"""
Appending to an empty docstring simply replaces the docstring.
"""

def noDocstring():
pass

_appendToDocstring(noDocstring, "Appended text.")
self.assertEqual("Appended text.", noDocstring.__doc__)


def test_appendToSingleLineDocstring(self):
"""
Appending to a single line docstring places the message on a new line,
with a blank line separating it from the rest of the docstring.

The docstring ends with a newline, conforming to Twisted and PEP 8
standards. Unfortunately, the indentation is incorrect, since the
existing docstring doesn't have enough info to help us indent
properly.
"""

def singleLineDocstring():
"""This doesn't comply with standards, but is here for a test."""

_appendToDocstring(singleLineDocstring, "Appended text.")
self.assertEqual(
["This doesn't comply with standards, but is here for a test.",
"",
"Appended text."],
singleLineDocstring.__doc__.splitlines())
self.assertTrue(singleLineDocstring.__doc__.endswith('\n'))


def test_appendToMultilineDocstring(self):
"""
Appending to a multi-line docstring places the messade on a new line,
with a blank line separating it from the rest of the docstring.

Because we have multiple lines, we have enough information to do
indentation.
"""

def multiLineDocstring():
"""
This is a multi-line docstring.
"""

def expectedDocstring():
"""
This is a multi-line docstring.

Appended text.
"""

_appendToDocstring(multiLineDocstring, "Appended text.")
self.assertEqual(
expectedDocstring.__doc__, multiLineDocstring.__doc__)