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

"""
Tests for L{twisted.internet._baseprocess} which implements process-related
functionality that is useful in all platforms supporting L{IReactorProcess}.
"""

__metaclass__ = type

from twisted.python.deprecate import getWarningMethod, setWarningMethod
from twisted.trial.unittest import TestCase
from twisted.internet._baseprocess import BaseProcess


class BaseProcessTests(TestCase):
"""
Tests for L{BaseProcess}, a parent class for other classes which represent
processes which implements functionality common to many different process
implementations.
"""
def test_callProcessExited(self):
"""
L{BaseProcess._callProcessExited} calls the C{processExited} method of
its C{proto} attribute and passes it a L{Failure} wrapping the given
exception.
"""
class FakeProto:
reason = None

def processExited(self, reason):
self.reason = reason

reason = RuntimeError("fake reason")
process = BaseProcess(FakeProto())
process._callProcessExited(reason)
process.proto.reason.trap(RuntimeError)
self.assertIs(reason, process.proto.reason.value)


def test_callProcessExitedMissing(self):
"""
L{BaseProcess._callProcessExited} emits a L{DeprecationWarning} if the
object referred to by its C{proto} attribute has no C{processExited}
method.
"""
class FakeProto:
pass

reason = object()
process = BaseProcess(FakeProto())

self.addCleanup(setWarningMethod, getWarningMethod())
warnings = []
def collect(message, category, stacklevel):
warnings.append((message, category, stacklevel))
setWarningMethod(collect)

process._callProcessExited(reason)

[(message, category, stacklevel)] = warnings
self.assertEqual(
message,
"Since Twisted 8.2, IProcessProtocol.processExited is required. "
"%s.%s must implement it." % (
FakeProto.__module__, FakeProto.__name__))
self.assertIs(category, DeprecationWarning)
# The stacklevel doesn't really make sense for this kind of
# deprecation. Requiring it to be 0 will at least avoid pointing to
# any part of Twisted or a random part of the application's code, which
# I think would be more misleading than having it point inside the
# warning system itself. -exarkun
self.assertEqual(stacklevel, 0)