from testfixtures import LogCapture from twisted.internet import defer from twisted.trial.unittest import TestCase import six from scrapy.http import Request from scrapy.crawler import CrawlerRunner from tests.spiders import MockServerSpider from tests.mockserver import MockServer class InjectArgumentsDownloaderMiddleware(object): """ Make sure downloader middlewares are able to update the keyword arguments """ def process_request(self, request, spider): if request.callback.__name__ == 'parse_downloader_mw': request.cb_kwargs['from_process_request'] = True return None def process_response(self, request, response, spider): if request.callback.__name__ == 'parse_downloader_mw': request.cb_kwargs['from_process_response'] = True return response class InjectArgumentsSpiderMiddleware(object): """ Make sure spider middlewares are able to update the keyword arguments """ def process_start_requests(self, start_requests, spider): for request in start_requests: if request.callback.__name__ == 'parse_spider_mw': request.cb_kwargs['from_process_start_requests'] = True yield request def process_spider_input(self, response, spider): request = response.request if request.callback.__name__ == 'parse_spider_mw': request.cb_kwargs['from_process_spider_input'] = True return None def process_spider_output(self, response, result, spider): for element in result: if isinstance(element, Request) and element.callback.__name__ == 'parse_spider_mw_2': element.cb_kwargs['from_process_spider_output'] = True yield element class KeywordArgumentsSpider(MockServerSpider): name = 'kwargs' custom_settings = { 'DOWNLOADER_MIDDLEWARES': { __name__ + '.InjectArgumentsDownloaderMiddleware': 750, }, 'SPIDER_MIDDLEWARES': { __name__ + '.InjectArgumentsSpiderMiddleware': 750, }, } checks = list() def start_requests(self): data = {'key': 'value', 'number': 123} yield Request(self.mockserver.url('/first'), self.parse_first, cb_kwargs=data) yield Request(self.mockserver.url('/general_with'), self.parse_general, cb_kwargs=data) yield Request(self.mockserver.url('/general_without'), self.parse_general) yield Request(self.mockserver.url('/no_kwargs'), self.parse_no_kwargs) yield Request(self.mockserver.url('/default'), self.parse_default, cb_kwargs=data) yield Request(self.mockserver.url('/takes_less'), self.parse_takes_less, cb_kwargs=data) yield Request(self.mockserver.url('/takes_more'), self.parse_takes_more, cb_kwargs=data) yield Request(self.mockserver.url('/downloader_mw'), self.parse_downloader_mw) yield Request(self.mockserver.url('/spider_mw'), self.parse_spider_mw) def parse_first(self, response, key, number): self.checks.append(key == 'value') self.checks.append(number == 123) self.crawler.stats.inc_value('boolean_checks', 2) yield response.follow( self.mockserver.url('/two'), self.parse_second, cb_kwargs={'new_key': 'new_value'}) def parse_second(self, response, new_key): self.checks.append(new_key == 'new_value') self.crawler.stats.inc_value('boolean_checks') def parse_general(self, response, **kwargs): if response.url.endswith('/general_with'): self.checks.append(kwargs['key'] == 'value') self.checks.append(kwargs['number'] == 123) self.crawler.stats.inc_value('boolean_checks', 2) elif response.url.endswith('/general_without'): self.checks.append(kwargs == {}) self.crawler.stats.inc_value('boolean_checks') def parse_no_kwargs(self, response): self.checks.append(response.url.endswith('/no_kwargs')) self.crawler.stats.inc_value('boolean_checks') def parse_default(self, response, key, number=None, default=99): self.checks.append(response.url.endswith('/default')) self.checks.append(key == 'value') self.checks.append(number == 123) self.checks.append(default == 99) self.crawler.stats.inc_value('boolean_checks', 4) def parse_takes_less(self, response, key): """ Should raise TypeError: parse_takes_less() got an unexpected keyword argument 'number' """ def parse_takes_more(self, response, key, number, other): """ Should raise TypeError: parse_takes_more() missing 1 required positional argument: 'other' """ def parse_downloader_mw(self, response, from_process_request, from_process_response): self.checks.append(bool(from_process_request)) self.checks.append(bool(from_process_response)) self.crawler.stats.inc_value('boolean_checks', 2) def parse_spider_mw(self, response, from_process_spider_input, from_process_start_requests): self.checks.append(bool(from_process_spider_input)) self.checks.append(bool(from_process_start_requests)) self.crawler.stats.inc_value('boolean_checks', 2) return Request(self.mockserver.url('/spider_mw_2'), self.parse_spider_mw_2) def parse_spider_mw_2(self, response, from_process_spider_output): self.checks.append(bool(from_process_spider_output)) self.crawler.stats.inc_value('boolean_checks', 1) class CallbackKeywordArgumentsTestCase(TestCase): maxDiff = None def setUp(self): self.mockserver = MockServer() self.mockserver.__enter__() self.runner = CrawlerRunner() def tearDown(self): self.mockserver.__exit__(None, None, None) @defer.inlineCallbacks def test_callback_kwargs(self): crawler = self.runner.create_crawler(KeywordArgumentsSpider) with LogCapture() as log: yield crawler.crawl(mockserver=self.mockserver) self.assertTrue(all(crawler.spider.checks)) self.assertEqual(len(crawler.spider.checks), crawler.stats.get_value('boolean_checks')) # check exceptions for argument mismatch exceptions = {} for line in log.records: for key in ('takes_less', 'takes_more'): if key in line.getMessage(): exceptions[key] = line self.assertEqual(exceptions['takes_less'].exc_info[0], TypeError) self.assertEqual(str(exceptions['takes_less'].exc_info[1]), "parse_takes_less() got an unexpected keyword argument 'number'") self.assertEqual(exceptions['takes_more'].exc_info[0], TypeError) # py2 and py3 messages are different exc_message = str(exceptions['takes_more'].exc_info[1]) if six.PY2: self.assertEqual(exc_message, "parse_takes_more() takes exactly 5 arguments (4 given)") elif six.PY3: self.assertEqual(exc_message, "parse_takes_more() missing 1 required positional argument: 'other'")