scrapy/tests/test_resolver.py

74 lines
2.2 KiB
Python

from __future__ import annotations
from unittest.mock import Mock
import pytest
from scrapy.resolver import CachingHostnameResolver, CachingThreadedResolver, dnscache
from scrapy.utils.defer import maybe_deferred_to_future
from scrapy.utils.test import get_crawler
from tests.utils.decorators import coroutine_test
@pytest.fixture(autouse=True)
def reset_dnscache():
original_limit = dnscache.limit
dnscache.clear()
yield
dnscache.clear()
dnscache.limit = original_limit
def test_caching_threaded_resolver_dnscache_disabled():
crawler = get_crawler(settings_dict={"DNSCACHE_ENABLED": False})
CachingThreadedResolver.from_crawler(crawler, Mock())
assert dnscache.limit == 0
@coroutine_test
async def test_caching_threaded_resolver_getHostByName_cache_hit():
resolver = CachingThreadedResolver(Mock(), cache_size=10, timeout=5.0)
dnscache["example.com"] = "1.2.3.4"
result = await maybe_deferred_to_future(resolver.getHostByName("example.com"))
assert result == "1.2.3.4"
def test_caching_hostname_resolver_dnscache_disabled():
crawler = get_crawler(settings_dict={"DNSCACHE_ENABLED": False})
CachingHostnameResolver.from_crawler(crawler, Mock())
assert dnscache.limit == 0
def test_caching_hostname_resolver_no_addresses_not_cached():
def fake_resolve(receiver, *_):
receiver.resolutionBegan(Mock())
receiver.resolutionComplete()
return receiver
reactor = Mock()
reactor.nameResolver.resolveHostName.side_effect = fake_resolve
resolver = CachingHostnameResolver(reactor, cache_size=10)
resolver.resolveHostName(Mock(), "example.com")
assert "example.com" not in dnscache
def test_caching_hostname_resolver_dnscache_disabled_rejects_storage():
def fake_resolve(receiver, *_):
receiver.resolutionBegan(Mock())
receiver.addressResolved(Mock())
receiver.resolutionComplete()
return receiver
reactor = Mock()
reactor.nameResolver.resolveHostName.side_effect = fake_resolve
resolver = CachingHostnameResolver(reactor, cache_size=0)
resolver.resolveHostName(Mock(), "example.com")
assert "example.com" not in dnscache
assert len(dnscache) == 0