[test] Name resolvers

tests/CrawlerProcess/alternative_name_resolver.py

@@ -0,0 +1,15 @@
+import scrapy
+from scrapy.crawler import CrawlerProcess
+
+
+class IPv6Spider(scrapy.Spider):
+    name = "ipv6_spider"
+    start_urls = ["http://[::1]"]
+
+
+process = CrawlerProcess(settings={
+    "RETRY_ENABLED": False,
+    "DNS_RESOLVER": "scrapy.resolver.CachingHostnameResolver",
+})
+process.crawl(IPv6Spider)
+process.start()

tests/CrawlerProcess/default_name_resolver.py

@@ -0,0 +1,12 @@
+import scrapy
+from scrapy.crawler import CrawlerProcess
+
+
+class IPv6Spider(scrapy.Spider):
+    name = "ipv6_spider"
+    start_urls = ["http://[::1]"]
+
+
+process = CrawlerProcess(settings={"RETRY_ENABLED": False})
+process.crawl(IPv6Spider)
+process.start()

tests/test_crawler.py

@@ -305,3 +305,15 @@ class CrawlerProcessSubprocess(unittest.TestCase):
         log = self.run_script('asyncio_enabled_reactor.py')
         self.assertIn('Spider closed (finished)', log)
         self.assertIn("DEBUG: Asyncio reactor is installed", log)
+
+    def test_default_name_resolver(self):
+        log = self.run_script('default_name_resolver.py')
+        self.assertIn('Spider closed (finished)', log)
+        self.assertIn("twisted.internet.error.DNSLookupError: DNS lookup failed: no results for hostname lookup: ::1.", log)
+        self.assertIn("'downloader/exception_type_count/twisted.internet.error.DNSLookupError': 1,", log)
+
+    def test_alternative_name_resolver(self):
+        log = self.run_script('alternative_name_resolver.py')
+        self.assertIn('Spider closed (finished)', log)
+        self.assertIn("twisted.internet.error.ConnectionRefusedError: Connection was refused by other side: 111: Connection refused.", log)
+        self.assertIn("'downloader/exception_type_count/twisted.internet.error.ConnectionRefusedError': 1,", log)