scrapy/tests/test_webclient.py

"""
from twisted.internet import defer
Tests borrowed from the twisted.web.client tests.
"""

from __future__ import annotations

import shutil
from pathlib import Path
from tempfile import mkdtemp
from urllib.parse import urlparse

import OpenSSL.SSL
import pytest
from twisted.internet import defer
from twisted.internet.defer import inlineCallbacks
from twisted.internet.testing import StringTransport
from twisted.protocols.policies import WrappingFactory
from twisted.trial import unittest
from twisted.web import resource, server, static, util
from twisted.web.client import _makeGetterFactory

from scrapy.core.downloader import webclient as client
from scrapy.core.downloader.contextfactory import ScrapyClientContextFactory
from scrapy.http import Headers, Request
from scrapy.utils.misc import build_from_crawler
from scrapy.utils.python import to_bytes, to_unicode
from scrapy.utils.test import get_crawler
from tests.mockserver import (
    BrokenDownloadResource,
    ErrorResource,
    ForeverTakingResource,
    HostHeaderResource,
    NoLengthResource,
    PayloadResource,
    ssl_context_factory,
)
from tests.test_core_downloader import TestContextFactoryBase


def getPage(url, contextFactory=None, response_transform=None, *args, **kwargs):
    """Adapted version of twisted.web.client.getPage"""

    def _clientfactory(url, *args, **kwargs):
        url = to_unicode(url)
        timeout = kwargs.pop("timeout", 0)
        f = client.ScrapyHTTPClientFactory(
            Request(url, *args, **kwargs), timeout=timeout
        )
        f.deferred.addCallback(response_transform or (lambda r: r.body))
        return f

    return _makeGetterFactory(
        to_bytes(url),
        _clientfactory,
        contextFactory=contextFactory,
        *args,
        **kwargs,
    ).deferred


@pytest.mark.filterwarnings("ignore::scrapy.exceptions.ScrapyDeprecationWarning")
class TestScrapyHTTPPageGetter:
    def test_earlyHeaders(self):
        # basic test stolen from twisted HTTPageGetter
        factory = client.ScrapyHTTPClientFactory(
            Request(
                url="http://foo/bar",
                body="some data",
                headers={
                    "Host": "example.net",
                    "User-Agent": "fooble",
                    "Cookie": "blah blah",
                    "Content-Length": "12981",
                    "Useful": "value",
                },
            )
        )

        self._test(
            factory,
            b"GET /bar HTTP/1.0\r\n"
            b"Content-Length: 9\r\n"
            b"Useful: value\r\n"
            b"Connection: close\r\n"
            b"User-Agent: fooble\r\n"
            b"Host: example.net\r\n"
            b"Cookie: blah blah\r\n"
            b"\r\n"
            b"some data",
        )

        # test minimal sent headers
        factory = client.ScrapyHTTPClientFactory(Request("http://foo/bar"))
        self._test(factory, b"GET /bar HTTP/1.0\r\nHost: foo\r\n\r\n")

        # test a simple POST with body and content-type
        factory = client.ScrapyHTTPClientFactory(
            Request(
                method="POST",
                url="http://foo/bar",
                body="name=value",
                headers={"Content-Type": "application/x-www-form-urlencoded"},
            )
        )

        self._test(
            factory,
            b"POST /bar HTTP/1.0\r\n"
            b"Host: foo\r\n"
            b"Connection: close\r\n"
            b"Content-Type: application/x-www-form-urlencoded\r\n"
            b"Content-Length: 10\r\n"
            b"\r\n"
            b"name=value",
        )

        # test a POST method with no body provided
        factory = client.ScrapyHTTPClientFactory(
            Request(method="POST", url="http://foo/bar")
        )

        self._test(
            factory,
            b"POST /bar HTTP/1.0\r\nHost: foo\r\nContent-Length: 0\r\n\r\n",
        )

        # test with single and multivalued headers
        factory = client.ScrapyHTTPClientFactory(
            Request(
                url="http://foo/bar",
                headers={
                    "X-Meta-Single": "single",
                    "X-Meta-Multivalued": ["value1", "value2"],
                },
            )
        )

        self._test(
            factory,
            b"GET /bar HTTP/1.0\r\n"
            b"Host: foo\r\n"
            b"X-Meta-Multivalued: value1\r\n"
            b"X-Meta-Multivalued: value2\r\n"
            b"X-Meta-Single: single\r\n"
            b"\r\n",
        )

        # same test with single and multivalued headers but using Headers class
        factory = client.ScrapyHTTPClientFactory(
            Request(
                url="http://foo/bar",
                headers=Headers(
                    {
                        "X-Meta-Single": "single",
                        "X-Meta-Multivalued": ["value1", "value2"],
                    }
                ),
            )
        )

        self._test(
            factory,
            b"GET /bar HTTP/1.0\r\n"
            b"Host: foo\r\n"
            b"X-Meta-Multivalued: value1\r\n"
            b"X-Meta-Multivalued: value2\r\n"
            b"X-Meta-Single: single\r\n"
            b"\r\n",
        )

    def _test(self, factory, testvalue):
        transport = StringTransport()
        protocol = client.ScrapyHTTPPageGetter()
        protocol.factory = factory
        protocol.makeConnection(transport)
        assert set(transport.value().splitlines()) == set(testvalue.splitlines())
        return testvalue

    def test_non_standard_line_endings(self):
        # regression test for: http://dev.scrapy.org/ticket/258
        factory = client.ScrapyHTTPClientFactory(Request(url="http://foo/bar"))
        protocol = client.ScrapyHTTPPageGetter()
        protocol.factory = factory
        protocol.headers = Headers()
        protocol.dataReceived(b"HTTP/1.0 200 OK\n")
        protocol.dataReceived(b"Hello: World\n")
        protocol.dataReceived(b"Foo: Bar\n")
        protocol.dataReceived(b"\n")
        assert protocol.headers == Headers({"Hello": ["World"], "Foo": ["Bar"]})


class EncodingResource(resource.Resource):
    out_encoding = "cp1251"

    def render(self, request):
        body = to_unicode(request.content.read())
        request.setHeader(b"content-encoding", self.out_encoding)
        return body.encode(self.out_encoding)


@pytest.mark.filterwarnings("ignore::scrapy.exceptions.ScrapyDeprecationWarning")
class TestWebClient(unittest.TestCase):
    def _listen(self, site):
        from twisted.internet import reactor

        return reactor.listenTCP(0, site, interface="127.0.0.1")

    def setUp(self):
        self.tmpname = Path(mkdtemp())
        (self.tmpname / "file").write_bytes(b"0123456789")
        r = static.File(str(self.tmpname))
        r.putChild(b"redirect", util.Redirect(b"/file"))
        r.putChild(b"wait", ForeverTakingResource())
        r.putChild(b"error", ErrorResource())
        r.putChild(b"nolength", NoLengthResource())
        r.putChild(b"host", HostHeaderResource())
        r.putChild(b"payload", PayloadResource())
        r.putChild(b"broken", BrokenDownloadResource())
        r.putChild(b"encoding", EncodingResource())
        self.site = server.Site(r, timeout=None)
        self.wrapper = WrappingFactory(self.site)
        self.port = self._listen(self.wrapper)
        self.portno = self.port.getHost().port

    @inlineCallbacks
    def tearDown(self):
        yield self.port.stopListening()
        shutil.rmtree(self.tmpname)

    def getURL(self, path):
        return f"http://127.0.0.1:{self.portno}/{path}"

    @inlineCallbacks
    def testPayload(self):
        s = "0123456789" * 10
        body = yield getPage(self.getURL("payload"), body=s)
        assert body == to_bytes(s)

    @inlineCallbacks
    def testHostHeader(self):
        # if we pass Host header explicitly, it should be used, otherwise
        # it should extract from url
        body = yield getPage(self.getURL("host"))
        assert body == to_bytes(f"127.0.0.1:{self.portno}")
        body = yield getPage(self.getURL("host"), headers={"Host": "www.example.com"})
        assert body == to_bytes("www.example.com")

    @inlineCallbacks
    def test_getPage(self):
        """
        L{client.getPage} returns a L{Deferred} which is called back with
        the body of the response if the default method B{GET} is used.
        """
        body = yield getPage(self.getURL("file"))
        assert body == b"0123456789"

    @inlineCallbacks
    def test_getPageHead(self):
        """
        L{client.getPage} returns a L{Deferred} which is called back with
        the empty string if the method is C{HEAD} and there is a successful
        response code.
        """

        def _getPage(method):
            return getPage(self.getURL("file"), method=method)

        body = yield _getPage("head")
        assert body == b""
        body = yield _getPage("HEAD")
        assert body == b""

    @inlineCallbacks
    def test_timeoutNotTriggering(self):
        """
        When a non-zero timeout is passed to L{getPage} and the page is
        retrieved before the timeout period elapses, the L{Deferred} is
        called back with the contents of the page.
        """
        body = yield getPage(self.getURL("host"), timeout=100)
        assert body == to_bytes(f"127.0.0.1:{self.portno}")

    @inlineCallbacks
    def test_timeoutTriggering(self):
        """
        When a non-zero timeout is passed to L{getPage} and that many
        seconds elapse before the server responds to the request. the
        L{Deferred} is errbacked with a L{error.TimeoutError}.
        """
        with pytest.raises(defer.TimeoutError):
            yield getPage(self.getURL("wait"), timeout=0.000001)
        # Clean up the server which is hanging around not doing
        # anything.
        connected = list(self.wrapper.protocols.keys())
        # There might be nothing here if the server managed to already see
        # that the connection was lost.
        if connected:
            connected[0].transport.loseConnection()

    @inlineCallbacks
    def testNotFound(self):
        body = yield getPage(self.getURL("notsuchfile"))
        assert b"404 - No Such Resource" in body

    @inlineCallbacks
    def testFactoryInfo(self):
        from twisted.internet import reactor

        url = self.getURL("file")
        parsed = urlparse(url)
        factory = client.ScrapyHTTPClientFactory(Request(url))
        reactor.connectTCP(parsed.hostname, parsed.port, factory)
        yield factory.deferred
        assert factory.status == b"200"
        assert factory.version.startswith(b"HTTP/")
        assert factory.message == b"OK"
        assert factory.response_headers[b"content-length"] == b"10"

    @inlineCallbacks
    def testRedirect(self):
        body = yield getPage(self.getURL("redirect"))
        assert (
            body
            == b'\n<html>\n    <head>\n        <meta http-equiv="refresh" content="0;URL=/file">\n'
            b'    </head>\n    <body bgcolor="#FFFFFF" text="#000000">\n    '
            b'<a href="/file">click here</a>\n    </body>\n</html>\n'
        )

    @inlineCallbacks
    def test_encoding(self):
        """Test that non-standart body encoding matches
        Content-Encoding header"""
        original_body = b"\xd0\x81\xd1\x8e\xd0\xaf"
        response = yield getPage(
            self.getURL("encoding"), body=original_body, response_transform=lambda r: r
        )
        content_encoding = to_unicode(response.headers[b"Content-Encoding"])
        assert content_encoding == EncodingResource.out_encoding
        assert response.body.decode(content_encoding) == to_unicode(original_body)


@pytest.mark.filterwarnings("ignore::scrapy.exceptions.ScrapyDeprecationWarning")
class TestWebClientSSL(TestContextFactoryBase):
    @inlineCallbacks
    def testPayload(self):
        s = "0123456789" * 10
        body = yield getPage(self.getURL("payload"), body=s)
        assert body == to_bytes(s)


class TestWebClientCustomCiphersSSL(TestWebClientSSL):
    # we try to use a cipher that is not enabled by default in OpenSSL
    custom_ciphers = "CAMELLIA256-SHA"
    context_factory = ssl_context_factory(cipher_string=custom_ciphers)

    @inlineCallbacks
    def testPayload(self):
        s = "0123456789" * 10
        crawler = get_crawler(
            settings_dict={"DOWNLOADER_CLIENT_TLS_CIPHERS": self.custom_ciphers}
        )
        client_context_factory = build_from_crawler(ScrapyClientContextFactory, crawler)
        body = yield getPage(
            self.getURL("payload"), body=s, contextFactory=client_context_factory
        )
        assert body == to_bytes(s)

    @inlineCallbacks
    def testPayloadDisabledCipher(self):
        s = "0123456789" * 10
        crawler = get_crawler(
            settings_dict={
                "DOWNLOADER_CLIENT_TLS_CIPHERS": "ECDHE-RSA-AES256-GCM-SHA384"
            }
        )
        client_context_factory = build_from_crawler(ScrapyClientContextFactory, crawler)
        with pytest.raises(OpenSSL.SSL.Error):
            yield getPage(
                self.getURL("payload"), body=s, contextFactory=client_context_factory
            )