Mini Shell

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

"""
Tests for L{twisted.internet.stdio}.
"""


from twisted.internet.protocol import Protocol
from twisted.internet.test.reactormixins import ReactorBuilder
from twisted.python.runtime import platform

if not platform.isWindows():
    from twisted.internet.stdio import StandardIO


class StdioFilesTests(ReactorBuilder):
    """
    L{StandardIO} supports reading and writing to filesystem files.
    """

    def setUp(self):
        path = self.mktemp()
        open(path, "wb").close()
        self.extraFile = open(path, "rb+")
        self.addCleanup(self.extraFile.close)

    def test_addReader(self):
        """
        Adding a filesystem file reader to a reactor will make sure it is
        polled.
        """
        reactor = self.buildReactor()

        class DataProtocol(Protocol):
            data = b""

            def dataReceived(self, data):
                self.data += data
                # It'd be better to stop reactor on connectionLost, but that
                # fails on FreeBSD, probably due to
                # http://bugs.python.org/issue9591:
                if self.data == b"hello!":
                    reactor.stop()

        path = self.mktemp()

        with open(path, "wb") as f:
            f.write(b"hello!")

        with open(path, "rb") as f:
            # Read bytes from a file, deliver them to a protocol instance:
            protocol = DataProtocol()
            StandardIO(
                protocol,
                stdin=f.fileno(),
                stdout=self.extraFile.fileno(),
                reactor=reactor,
            )
            self.runReactor(reactor)

        self.assertEqual(protocol.data, b"hello!")

    def test_addWriter(self):
        """
        Adding a filesystem file writer to a reactor will make sure it is
        polled.
        """
        reactor = self.buildReactor()

        class DisconnectProtocol(Protocol):
            def connectionLost(self, reason):
                reactor.stop()

        path = self.mktemp()

        with open(path, "wb") as f:
            # Write bytes to a transport, hopefully have them written to a
            # file:
            protocol = DisconnectProtocol()
            StandardIO(
                protocol,
                stdout=f.fileno(),
                stdin=self.extraFile.fileno(),
                reactor=reactor,
            )
            protocol.transport.write(b"hello")
            protocol.transport.write(b", world")
            protocol.transport.loseConnection()

            self.runReactor(reactor)

        with open(path, "rb") as f:
            self.assertEqual(f.read(), b"hello, world")

    def test_removeReader(self):
        """
        Removing a filesystem file reader from a reactor will make sure it is
        no longer polled.
        """
        reactor = self.buildReactor()
        self.addCleanup(self.unbuildReactor, reactor)

        path = self.mktemp()
        open(path, "wb").close()

        with open(path, "rb") as f:
            # Have the reader added:
            stdio = StandardIO(
                Protocol(),
                stdin=f.fileno(),
                stdout=self.extraFile.fileno(),
                reactor=reactor,
            )
            self.assertIn(stdio._reader, reactor.getReaders())
            stdio._reader.stopReading()
            self.assertNotIn(stdio._reader, reactor.getReaders())

    def test_removeWriter(self):
        """
        Removing a filesystem file writer from a reactor will make sure it is
        no longer polled.
        """
        reactor = self.buildReactor()
        self.addCleanup(self.unbuildReactor, reactor)

        # Cleanup might fail if file is GCed too soon:
        self.f = f = open(self.mktemp(), "wb")

        # Have the reader added:
        protocol = Protocol()
        stdio = StandardIO(
            protocol, stdout=f.fileno(), stdin=self.extraFile.fileno(), reactor=reactor
        )
        protocol.transport.write(b"hello")
        self.assertIn(stdio._writer, reactor.getWriters())
        stdio._writer.stopWriting()
        self.assertNotIn(stdio._writer, reactor.getWriters())

    def test_removeAll(self):
        """
        Calling C{removeAll} on a reactor includes descriptors that are
        filesystem files.
        """
        reactor = self.buildReactor()
        self.addCleanup(self.unbuildReactor, reactor)

        path = self.mktemp()
        open(path, "wb").close()

        # Cleanup might fail if file is GCed too soon:
        self.f = f = open(path, "rb")

        # Have the reader added:
        stdio = StandardIO(
            Protocol(),
            stdin=f.fileno(),
            stdout=self.extraFile.fileno(),
            reactor=reactor,
        )
        # And then removed:
        removed = reactor.removeAll()
        self.assertIn(stdio._reader, removed)
        self.assertNotIn(stdio._reader, reactor.getReaders())

    def test_getReaders(self):
        """
        C{reactor.getReaders} includes descriptors that are filesystem files.
        """
        reactor = self.buildReactor()
        self.addCleanup(self.unbuildReactor, reactor)

        path = self.mktemp()
        open(path, "wb").close()

        # Cleanup might fail if file is GCed too soon:
        with open(path, "rb") as f:
            # Have the reader added:
            stdio = StandardIO(
                Protocol(),
                stdin=f.fileno(),
                stdout=self.extraFile.fileno(),
                reactor=reactor,
            )
            self.assertIn(stdio._reader, reactor.getReaders())

    def test_getWriters(self):
        """
        C{reactor.getWriters} includes descriptors that are filesystem files.
        """
        reactor = self.buildReactor()
        self.addCleanup(self.unbuildReactor, reactor)

        # Cleanup might fail if file is GCed too soon:
        self.f = f = open(self.mktemp(), "wb")

        # Have the reader added:
        stdio = StandardIO(
            Protocol(),
            stdout=f.fileno(),
            stdin=self.extraFile.fileno(),
            reactor=reactor,
        )
        self.assertNotIn(stdio._writer, reactor.getWriters())
        stdio._writer.startWriting()
        self.assertIn(stdio._writer, reactor.getWriters())

    if platform.isWindows():
        skip = (
            "StandardIO does not accept stdout as an argument to Windows. "
            "Testing redirection to a file is therefore harder."
        )


globals().update(StdioFilesTests.makeTestCaseClasses())