scrapy/tests/test_spidermiddleware.py

282 lines
10 KiB
Python

import collections.abc
from unittest import mock
from twisted.internet import defer
from twisted.trial.unittest import TestCase
from twisted.python.failure import Failure
from scrapy.spiders import Spider
from scrapy.http import Request, Response
from scrapy.exceptions import _InvalidOutput
from scrapy.utils.asyncgen import _process_iterable_universal, as_async_generator, collect_asyncgen
from scrapy.utils.defer import deferred_from_coro
from scrapy.utils.test import get_crawler
from scrapy.core.spidermw import SpiderMiddlewareManager
class SpiderMiddlewareTestCase(TestCase):
def setUp(self):
self.request = Request('http://example.com/index.html')
self.response = Response(self.request.url, request=self.request)
self.crawler = get_crawler(Spider)
self.spider = self.crawler._create_spider('foo')
self.mwman = SpiderMiddlewareManager.from_crawler(self.crawler)
def _scrape_response(self):
"""Execute spider mw manager's scrape_response method and return the result.
Raise exception in case of failure.
"""
scrape_func = mock.MagicMock()
dfd = self.mwman.scrape_response(scrape_func, self.response, self.request, self.spider)
# catch deferred result and return the value
results = []
dfd.addBoth(results.append)
self._wait(dfd)
ret = results[0]
return ret
class ProcessSpiderInputInvalidOutput(SpiderMiddlewareTestCase):
"""Invalid return value for process_spider_input method"""
def test_invalid_process_spider_input(self):
class InvalidProcessSpiderInputMiddleware:
def process_spider_input(self, response, spider):
return 1
self.mwman._add_middleware(InvalidProcessSpiderInputMiddleware())
result = self._scrape_response()
self.assertIsInstance(result, Failure)
self.assertIsInstance(result.value, _InvalidOutput)
class ProcessSpiderOutputInvalidOutput(SpiderMiddlewareTestCase):
"""Invalid return value for process_spider_output method"""
def test_invalid_process_spider_output(self):
class InvalidProcessSpiderOutputMiddleware:
def process_spider_output(self, response, result, spider):
return 1
self.mwman._add_middleware(InvalidProcessSpiderOutputMiddleware())
result = self._scrape_response()
self.assertIsInstance(result, Failure)
self.assertIsInstance(result.value, _InvalidOutput)
class ProcessSpiderExceptionInvalidOutput(SpiderMiddlewareTestCase):
"""Invalid return value for process_spider_exception method"""
def test_invalid_process_spider_exception(self):
class InvalidProcessSpiderOutputExceptionMiddleware:
def process_spider_exception(self, response, exception, spider):
return 1
class RaiseExceptionProcessSpiderOutputMiddleware:
def process_spider_output(self, response, result, spider):
raise Exception()
self.mwman._add_middleware(InvalidProcessSpiderOutputExceptionMiddleware())
self.mwman._add_middleware(RaiseExceptionProcessSpiderOutputMiddleware())
result = self._scrape_response()
self.assertIsInstance(result, Failure)
self.assertIsInstance(result.value, _InvalidOutput)
class ProcessSpiderExceptionReRaise(SpiderMiddlewareTestCase):
"""Re raise the exception by returning None"""
def test_process_spider_exception_return_none(self):
class ProcessSpiderExceptionReturnNoneMiddleware:
def process_spider_exception(self, response, exception, spider):
return None
class RaiseExceptionProcessSpiderOutputMiddleware:
def process_spider_output(self, response, result, spider):
1 / 0
self.mwman._add_middleware(ProcessSpiderExceptionReturnNoneMiddleware())
self.mwman._add_middleware(RaiseExceptionProcessSpiderOutputMiddleware())
result = self._scrape_response()
self.assertIsInstance(result, Failure)
self.assertIsInstance(result.value, ZeroDivisionError)
class BaseAsyncSpiderMiddlewareTestCase(SpiderMiddlewareTestCase):
""" Helpers for testing sync, async and mixed middlewares.
Should work for process_spider_output and, when it's supported, process_start_requests.
"""
RESULT_COUNT = 3 # to simplify checks, let everything return 3 objects
@defer.inlineCallbacks
def _get_middleware_result(self, *mw_classes):
for mw_cls in mw_classes:
self.mwman._add_middleware(mw_cls())
result = yield self.mwman.scrape_response(self._scrape_func, self.response, self.request, self.spider)
return result
@defer.inlineCallbacks
def _test_simple_base(self, *mw_classes):
result = yield self._get_middleware_result(*mw_classes)
self.assertIsInstance(result, collections.abc.Iterable)
result_list = list(result)
self.assertEqual(len(result_list), self.RESULT_COUNT)
self.assertIsInstance(result_list[0], self.ITEM_TYPE)
@defer.inlineCallbacks
def _test_asyncgen_base(self, *mw_classes):
result = yield self._get_middleware_result(*mw_classes)
self.assertIsInstance(result, collections.abc.AsyncIterator)
result_list = yield deferred_from_coro(collect_asyncgen(result))
self.assertEqual(len(result_list), self.RESULT_COUNT)
self.assertIsInstance(result_list[0], self.ITEM_TYPE)
@defer.inlineCallbacks
def _test_asyncgen_fail(self, *mw_classes):
with self.assertRaisesRegex(TypeError, "Synchronous .+ called with an async iterable"):
yield self._get_middleware_result(*mw_classes)
class ProcessSpiderOutputSimpleMiddleware:
def process_spider_output(self, response, result, spider):
for r in result:
yield r
class ProcessSpiderOutputAsyncGenMiddleware:
async def process_spider_output(self, response, result, spider):
async for r in as_async_generator(result):
yield r
class ProcessSpiderOutputUniversalMiddleware:
def process_spider_output(self, response, result, spider):
@_process_iterable_universal
async def process(result):
async for r in result:
yield r
return process(result)
class ProcessSpiderOutputSimple(BaseAsyncSpiderMiddlewareTestCase):
""" process_spider_output tests for simple callbacks"""
ITEM_TYPE = dict
MW_SIMPLE = ProcessSpiderOutputSimpleMiddleware
MW_ASYNCGEN = ProcessSpiderOutputAsyncGenMiddleware
MW_UNIVERSAL = ProcessSpiderOutputUniversalMiddleware
def _scrape_func(self, *args, **kwargs):
yield {'foo': 1}
yield {'foo': 2}
yield {'foo': 3}
def test_simple(self):
""" Simple mw """
return self._test_simple_base(self.MW_SIMPLE)
def test_asyncgen(self):
""" Asyncgen mw """
return self._test_asyncgen_base(self.MW_ASYNCGEN)
def test_simple_asyncgen(self):
""" Simple mw -> asyncgen mw """
return self._test_asyncgen_base(self.MW_ASYNCGEN,
self.MW_SIMPLE)
def test_asyncgen_simple(self):
""" Asyncgen mw -> simple mw; cannot work """
return self._test_asyncgen_fail(self.MW_SIMPLE,
self.MW_ASYNCGEN)
def test_universal(self):
""" Universal mw """
return self._test_simple_base(self.MW_UNIVERSAL)
def test_universal_simple(self):
""" Universal mw -> simple mw """
return self._test_simple_base(self.MW_SIMPLE,
self.MW_UNIVERSAL)
def test_simple_universal(self):
""" Simple mw -> universal mw """
return self._test_simple_base(self.MW_UNIVERSAL,
self.MW_SIMPLE)
def test_universal_asyncgen(self):
""" Universal mw -> asyncgen mw """
return self._test_asyncgen_base(self.MW_ASYNCGEN,
self.MW_UNIVERSAL)
def test_asyncgen_universal(self):
""" Asyncgen mw -> universal mw """
return self._test_asyncgen_base(self.MW_UNIVERSAL,
self.MW_ASYNCGEN)
class ProcessSpiderOutputAsyncGen(ProcessSpiderOutputSimple):
""" process_spider_output tests for async generator callbacks """
async def _scrape_func(self, *args, **kwargs):
for item in super()._scrape_func():
yield item
def test_simple(self):
""" Simple mw; cannot work """
return self._test_asyncgen_fail(self.MW_SIMPLE)
def test_simple_asyncgen(self):
""" Simple mw -> asyncgen mw; cannot work """
return self._test_asyncgen_fail(self.MW_ASYNCGEN,
self.MW_SIMPLE)
def test_universal(self):
""" Universal mw """
return self._test_asyncgen_base(self.MW_UNIVERSAL)
def test_universal_simple(self):
""" Universal mw -> simple mw; cannot work """
return self._test_asyncgen_fail(self.MW_SIMPLE,
self.MW_UNIVERSAL)
def test_simple_universal(self):
""" Simple mw -> universal mw; cannot work """
return self._test_asyncgen_fail(self.MW_UNIVERSAL,
self.MW_SIMPLE)
class ProcessStartRequestsSimpleMiddleware:
def process_start_requests(self, start_requests, spider):
for r in start_requests:
yield r
class ProcessStartRequestsSimple(BaseAsyncSpiderMiddlewareTestCase):
""" process_start_requests tests for simple start_requests"""
ITEM_TYPE = Request
MW_SIMPLE = ProcessStartRequestsSimpleMiddleware
def _start_requests(self):
for i in range(3):
yield Request(f'https://example.com/{i}', dont_filter=True)
@defer.inlineCallbacks
def _get_middleware_result(self, *mw_classes):
for mw_cls in mw_classes:
self.mwman._add_middleware(mw_cls())
start_requests = iter(self._start_requests())
results = yield self.mwman.process_start_requests(start_requests, self.spider)
return results
def test_simple(self):
""" Simple mw """
self._test_simple_base(self.MW_SIMPLE)