scrapy/tests/test_engine.py

772 lines
27 KiB
Python

from __future__ import annotations
import asyncio
import re
import subprocess
import sys
from collections import defaultdict
from dataclasses import dataclass
from typing import TYPE_CHECKING, Any, cast
from unittest.mock import Mock, call
from urllib.parse import urlparse
import attr
import pytest
from itemadapter import ItemAdapter
from pydispatch import dispatcher
from testfixtures import LogCapture
from twisted.internet import defer
from scrapy import signals
from scrapy.core.engine import ExecutionEngine, _Slot
from scrapy.core.scheduler import BaseScheduler
from scrapy.exceptions import CloseSpider, IgnoreRequest
from scrapy.http import Headers, Request, Response
from scrapy.item import Field, Item
from scrapy.linkextractors import LinkExtractor
from scrapy.spiders import Spider
from scrapy.statscollectors import MemoryStatsCollector
from scrapy.utils.defer import (
_schedule_coro,
deferred_from_coro,
maybe_deferred_to_future,
)
from scrapy.utils.signal import disconnect_all
from scrapy.utils.spider import DefaultSpider
from scrapy.utils.test import get_crawler
from tests import get_testdata
from tests.utils.decorators import coroutine_test, inline_callbacks_test
if TYPE_CHECKING:
from collections.abc import AsyncIterator
from twisted.python.failure import Failure
from scrapy.core.scheduler import Scheduler
from scrapy.crawler import Crawler
from tests.mockserver.http import MockServer
class MyItem(Item):
name = Field()
url = Field()
price = Field()
@attr.s
class AttrsItem:
name = attr.ib(default="")
url = attr.ib(default="")
price = attr.ib(default=0)
@dataclass
class DataClassItem:
name: str = ""
url: str = ""
price: int = 0
class MySpider(Spider):
name = "scrapytest.org"
itemurl_re = re.compile(r"item\d+.html")
name_re = re.compile(r"<h1>(.*?)</h1>", re.MULTILINE)
price_re = re.compile(r">Price: \$(.*?)<", re.MULTILINE)
item_cls: type = MyItem
def parse(self, response):
xlink = LinkExtractor()
itemre = re.compile(self.itemurl_re)
for link in xlink.extract_links(response):
if itemre.search(link.url):
yield Request(url=link.url, callback=self.parse_item)
def parse_item(self, response):
adapter = ItemAdapter(self.item_cls())
m = self.name_re.search(response.text)
if m:
adapter["name"] = m.group(1)
adapter["url"] = response.url
m = self.price_re.search(response.text)
if m:
adapter["price"] = m.group(1)
return adapter.item
class DupeFilterSpider(MySpider):
async def start(self):
for url in self.start_urls:
yield Request(url) # no dont_filter=True
class DictItemsSpider(MySpider):
item_cls = dict
class AttrsItemsSpider(MySpider):
item_cls = AttrsItem
class DataClassItemsSpider(MySpider):
item_cls = DataClassItem
class ItemZeroDivisionErrorSpider(MySpider):
custom_settings = {
"ITEM_PIPELINES": {
"tests.pipelines.ProcessWithZeroDivisionErrorPipeline": 300,
}
}
class ChangeCloseReasonSpider(MySpider):
@classmethod
def from_crawler(cls, crawler, *args, **kwargs):
spider = cls(*args, **kwargs)
spider._set_crawler(crawler)
crawler.signals.connect(spider.spider_idle, signals.spider_idle)
return spider
def spider_idle(self):
raise CloseSpider(reason="custom_reason")
class CrawlerRun:
"""A class to run the crawler and keep track of events occurred"""
def __init__(self, spider_class: type[Spider]):
self.respplug: list[tuple[Response, Spider]] = []
self.reqplug: list[tuple[Request, Spider]] = []
self.reqdropped: list[tuple[Request, Spider]] = []
self.reqreached: list[tuple[Request, Spider]] = []
self.itemerror: list[tuple[Any, Response, Spider, Failure]] = []
self.itemresp: list[tuple[Any, Response]] = []
self.headers: dict[Request, Headers] = {}
self.bytes: defaultdict[Request, list[bytes]] = defaultdict(list)
self.signals_caught: dict[Any, dict[str, Any]] = {}
self.spider_class = spider_class
async def run(self, mockserver: MockServer) -> None:
self.mockserver = mockserver
start_urls = [
self.geturl("/static/"),
self.geturl("/redirect"),
self.geturl("/redirect"), # duplicate
self.geturl("/numbers"),
]
for name, signal in vars(signals).items():
if not name.startswith("_"):
dispatcher.connect(self.record_signal, signal)
self.crawler = get_crawler(self.spider_class)
self.crawler.signals.connect(self.item_scraped, signals.item_scraped)
self.crawler.signals.connect(self.item_error, signals.item_error)
self.crawler.signals.connect(self.headers_received, signals.headers_received)
self.crawler.signals.connect(self.bytes_received, signals.bytes_received)
self.crawler.signals.connect(self.request_scheduled, signals.request_scheduled)
self.crawler.signals.connect(self.request_dropped, signals.request_dropped)
self.crawler.signals.connect(
self.request_reached, signals.request_reached_downloader
)
self.crawler.signals.connect(
self.response_downloaded, signals.response_downloaded
)
self.crawler.crawl(start_urls=start_urls)
self.deferred: defer.Deferred[None] = defer.Deferred()
dispatcher.connect(self.stop, signals.engine_stopped)
await maybe_deferred_to_future(self.deferred)
async def stop(self):
for name, signal in vars(signals).items():
if not name.startswith("_"):
disconnect_all(signal)
self.deferred.callback(None)
await self.crawler.stop_async()
def geturl(self, path: str) -> str:
return self.mockserver.url(path)
def getpath(self, url: str) -> str:
u = urlparse(url)
return u.path
def item_error(
self, item: Any, response: Response, spider: Spider, failure: Failure
) -> None:
self.itemerror.append((item, response, spider, failure))
def item_scraped(self, item: Any, spider: Spider, response: Response) -> None:
self.itemresp.append((item, response))
def headers_received(
self, headers: Headers, body_length: int, request: Request, spider: Spider
) -> None:
self.headers[request] = headers
def bytes_received(self, data: bytes, request: Request, spider: Spider) -> None:
self.bytes[request].append(data)
def request_scheduled(self, request: Request, spider: Spider) -> None:
self.reqplug.append((request, spider))
def request_reached(self, request: Request, spider: Spider) -> None:
self.reqreached.append((request, spider))
def request_dropped(self, request: Request, spider: Spider) -> None:
self.reqdropped.append((request, spider))
def response_downloaded(self, response: Response, spider: Spider) -> None:
self.respplug.append((response, spider))
def record_signal(self, *args: Any, **kwargs: Any) -> None:
"""Record a signal and its parameters"""
signalargs = kwargs.copy()
sig = signalargs.pop("signal")
signalargs.pop("sender", None)
self.signals_caught[sig] = signalargs
class TestEngineBase:
@staticmethod
def _assert_visited_urls(run: CrawlerRun) -> None:
must_be_visited = [
"/static/",
"/redirect",
"/redirected",
"/static/item1.html",
"/static/item2.html",
"/static/item999.html",
]
urls_visited = {rp[0].url for rp in run.respplug}
urls_expected = {run.geturl(p) for p in must_be_visited}
assert urls_expected <= urls_visited, (
f"URLs not visited: {list(urls_expected - urls_visited)}"
)
@staticmethod
def _assert_scheduled_requests(run: CrawlerRun, count: int) -> None:
assert len(run.reqplug) == count
paths_expected = [
"/static/item999.html",
"/static/item2.html",
"/static/item1.html",
]
urls_requested = {rq[0].url for rq in run.reqplug}
urls_expected = {run.geturl(p) for p in paths_expected}
assert urls_expected <= urls_requested
scheduled_requests_count = len(run.reqplug)
dropped_requests_count = len(run.reqdropped)
responses_count = len(run.respplug)
assert scheduled_requests_count == dropped_requests_count + responses_count
assert len(run.reqreached) == responses_count
@staticmethod
def _assert_dropped_requests(run: CrawlerRun) -> None:
assert len(run.reqdropped) == 1
@staticmethod
def _assert_downloaded_responses(run: CrawlerRun, count: int) -> None:
# response tests
assert len(run.respplug) == count
assert len(run.reqreached) == count
for response, _ in run.respplug:
if run.getpath(response.url) == "/static/item999.html":
assert response.status == 404
if run.getpath(response.url) == "/redirect":
assert response.status == 302
@staticmethod
def _assert_items_error(run: CrawlerRun) -> None:
assert len(run.itemerror) == 2
for item, response, spider, failure in run.itemerror:
assert failure.value.__class__ is ZeroDivisionError
assert spider == run.crawler.spider
assert item["url"] == response.url
if "item1.html" in item["url"]:
assert item["name"] == "Item 1 name"
assert item["price"] == "100"
if "item2.html" in item["url"]:
assert item["name"] == "Item 2 name"
assert item["price"] == "200"
@staticmethod
def _assert_scraped_items(run: CrawlerRun) -> None:
assert len(run.itemresp) == 2
for item_, response in run.itemresp:
item = ItemAdapter(item_)
assert item["url"] == response.url
if "item1.html" in item["url"]:
assert item["name"] == "Item 1 name"
assert item["price"] == "100"
if "item2.html" in item["url"]:
assert item["name"] == "Item 2 name"
assert item["price"] == "200"
@staticmethod
def _assert_headers_received(run: CrawlerRun) -> None:
for headers in run.headers.values():
assert b"Server" in headers
assert headers[b"Server"]
assert b"TwistedWeb" in headers[b"Server"]
assert b"Date" in headers
assert b"Content-Type" in headers
@staticmethod
def _assert_bytes_received(run: CrawlerRun) -> None:
assert len(run.bytes) == 9
for request, data in run.bytes.items():
joined_data = b"".join(data)
if run.getpath(request.url) == "/static/":
assert joined_data == get_testdata("test_site", "index.html")
elif run.getpath(request.url) == "/static/item1.html":
assert joined_data == get_testdata("test_site", "item1.html")
elif run.getpath(request.url) == "/static/item2.html":
assert joined_data == get_testdata("test_site", "item2.html")
elif run.getpath(request.url) == "/redirected":
assert joined_data == b"Redirected here"
elif run.getpath(request.url) == "/redirect":
assert (
joined_data == b"\n<html>\n"
b" <head>\n"
b' <meta http-equiv="refresh" content="0;URL=/redirected">\n'
b" </head>\n"
b' <body bgcolor="#FFFFFF" text="#000000">\n'
b' <a href="/redirected">click here</a>\n'
b" </body>\n"
b"</html>\n"
)
elif run.getpath(request.url) == "/static/item999.html":
assert (
joined_data == b"\n<html>\n"
b" <head><title>404 - No Such Resource</title></head>\n"
b" <body>\n"
b" <h1>No Such Resource</h1>\n"
b" <p>File not found.</p>\n"
b" </body>\n"
b"</html>\n"
)
elif run.getpath(request.url) == "/numbers":
# signal was fired multiple times
assert len(data) > 1
# bytes were received in order
numbers = [str(x).encode("utf8") for x in range(2**18)]
assert joined_data == b"".join(numbers)
@staticmethod
def _assert_signals_caught(run: CrawlerRun) -> None:
assert signals.engine_started in run.signals_caught
assert signals.engine_stopped in run.signals_caught
assert signals.spider_opened in run.signals_caught
assert signals.spider_idle in run.signals_caught
assert signals.spider_closed in run.signals_caught
assert signals.headers_received in run.signals_caught
assert {"spider": run.crawler.spider} == run.signals_caught[
signals.spider_opened
]
assert {"spider": run.crawler.spider} == run.signals_caught[signals.spider_idle]
assert {
"spider": run.crawler.spider,
"reason": "finished",
} == run.signals_caught[signals.spider_closed]
class TestEngine(TestEngineBase):
@coroutine_test
async def test_crawler(self, mockserver: MockServer) -> None:
for spider in (
MySpider,
DictItemsSpider,
AttrsItemsSpider,
DataClassItemsSpider,
):
run = CrawlerRun(spider)
await run.run(mockserver)
self._assert_visited_urls(run)
self._assert_scheduled_requests(run, count=9)
self._assert_downloaded_responses(run, count=9)
self._assert_scraped_items(run)
self._assert_signals_caught(run)
self._assert_headers_received(run)
self._assert_bytes_received(run)
@coroutine_test
async def test_crawler_dupefilter(self, mockserver: MockServer) -> None:
run = CrawlerRun(DupeFilterSpider)
await run.run(mockserver)
self._assert_scheduled_requests(run, count=8)
self._assert_dropped_requests(run)
@coroutine_test
async def test_crawler_itemerror(self, mockserver: MockServer) -> None:
run = CrawlerRun(ItemZeroDivisionErrorSpider)
await run.run(mockserver)
self._assert_items_error(run)
@coroutine_test
async def test_crawler_change_close_reason_on_idle(
self, mockserver: MockServer
) -> None:
run = CrawlerRun(ChangeCloseReasonSpider)
await run.run(mockserver)
assert {
"spider": run.crawler.spider,
"reason": "custom_reason",
} == run.signals_caught[signals.spider_closed]
@coroutine_test
async def test_close_downloader(self):
e = ExecutionEngine(get_crawler(MySpider), lambda _: None)
await e.close_async()
def test_close_without_downloader(self):
class CustomException(Exception):
pass
class BadDownloader:
def __init__(self, crawler):
raise CustomException
with pytest.raises(CustomException):
ExecutionEngine(
get_crawler(MySpider, {"DOWNLOADER": BadDownloader}), lambda _: None
)
@inline_callbacks_test
def test_start_already_running_exception(self):
crawler = get_crawler(DefaultSpider)
crawler.spider = crawler._create_spider()
e = ExecutionEngine(crawler, lambda _: None)
crawler.engine = e
yield deferred_from_coro(e.open_spider_async())
_schedule_coro(e.start_async())
with pytest.raises(RuntimeError, match="Engine already running"):
yield deferred_from_coro(e.start_async())
yield deferred_from_coro(e.stop_async())
@pytest.mark.only_asyncio
@coroutine_test
async def test_start_already_running_exception_asyncio(self):
crawler = get_crawler(DefaultSpider)
crawler.spider = crawler._create_spider()
e = ExecutionEngine(crawler, lambda _: None)
crawler.engine = e
await e.open_spider_async()
with pytest.raises(RuntimeError, match="Engine already running"):
await asyncio.gather(e.start_async(), e.start_async())
await e.stop_async()
@inline_callbacks_test
def test_start_request_processing_exception(self):
class BadRequestFingerprinter:
def fingerprint(self, request):
raise ValueError # to make Scheduler.enqueue_request() fail
class SimpleSpider(Spider):
name = "simple"
async def start(self):
yield Request("data:,")
crawler = get_crawler(
SimpleSpider, {"REQUEST_FINGERPRINTER_CLASS": BadRequestFingerprinter}
)
with LogCapture() as log:
yield crawler.crawl()
assert "Error while processing requests from start()" in str(log)
assert "Spider closed (shutdown)" in str(log)
def test_short_timeout(self):
args = (
sys.executable,
"-m",
"scrapy.cmdline",
"fetch",
"-s",
"CLOSESPIDER_TIMEOUT=0.001",
"-s",
"LOG_LEVEL=DEBUG",
"http://toscrape.com",
)
p = subprocess.Popen(
args,
stdout=subprocess.DEVNULL,
stderr=subprocess.PIPE,
)
try:
_, stderr = p.communicate(timeout=15)
except subprocess.TimeoutExpired:
p.kill()
p.communicate()
pytest.fail("Command took too much time to complete")
stderr_str = stderr.decode("utf-8")
assert "AttributeError" not in stderr_str, stderr_str
assert "AssertionError" not in stderr_str, stderr_str
class TestEngineDownloadAsync:
"""Test cases for ExecutionEngine.download_async()."""
@pytest.fixture
def engine(self) -> ExecutionEngine:
crawler = get_crawler(MySpider)
engine = ExecutionEngine(crawler, lambda _: None)
engine.downloader.close()
engine.downloader = Mock()
engine._slot = Mock()
engine._slot.inprogress = set()
return engine
@staticmethod
async def _download(engine: ExecutionEngine, request: Request) -> Response:
return await engine.download_async(request)
@coroutine_test
async def test_download_async_success(self, engine):
"""Test basic successful async download of a request."""
request = Request("http://example.com")
response = Response("http://example.com", body=b"test body")
engine.spider = Mock()
engine.downloader.fetch.return_value = defer.succeed(response)
engine._slot.add_request = Mock()
engine._slot.remove_request = Mock()
result = await self._download(engine, request)
assert result == response
engine._slot.add_request.assert_called_once_with(request)
engine._slot.remove_request.assert_called_once_with(request)
engine.downloader.fetch.assert_called_once_with(request)
@coroutine_test
async def test_download_async_redirect(self, engine):
"""Test async download with a redirect request."""
original_request = Request("http://example.com")
redirect_request = Request("http://example.com/redirect")
final_response = Response("http://example.com/redirect", body=b"redirected")
# First call returns redirect request, second call returns final response
engine.downloader.fetch.side_effect = [
defer.succeed(redirect_request),
defer.succeed(final_response),
]
engine.spider = Mock()
engine._slot.add_request = Mock()
engine._slot.remove_request = Mock()
result = await self._download(engine, original_request)
assert result == final_response
assert engine.downloader.fetch.call_count == 2
engine._slot.add_request.assert_has_calls(
[call(original_request), call(redirect_request)]
)
engine._slot.remove_request.assert_has_calls(
[call(original_request), call(redirect_request)]
)
@coroutine_test
async def test_download_async_no_spider(self, engine):
"""Test async download attempt when no spider is available."""
request = Request("http://example.com")
engine.spider = None
with pytest.raises(RuntimeError, match="No open spider to crawl:"):
await self._download(engine, request)
@coroutine_test
async def test_download_async_failure(self, engine):
"""Test async download when the downloader raises an exception."""
request = Request("http://example.com")
error = RuntimeError("Download failed")
engine.spider = Mock()
engine.downloader.fetch.return_value = defer.fail(error)
engine._slot.add_request = Mock()
engine._slot.remove_request = Mock()
with pytest.raises(RuntimeError, match="Download failed"):
await self._download(engine, request)
engine._slot.add_request.assert_called_once_with(request)
engine._slot.remove_request.assert_called_once_with(request)
@pytest.mark.filterwarnings("ignore::scrapy.exceptions.ScrapyDeprecationWarning")
class TestEngineDownload(TestEngineDownloadAsync):
"""Test cases for ExecutionEngine.download()."""
@staticmethod
async def _download(engine: ExecutionEngine, request: Request) -> Response:
return await maybe_deferred_to_future(engine.download(request))
@coroutine_test
async def test_request_scheduled_signal():
class TestScheduler(BaseScheduler):
def __init__(self) -> None:
self.enqueued: list[Request] = []
def enqueue_request(self, request: Request) -> bool:
self.enqueued.append(request)
return True
def signal_handler(request: Request, spider: Spider) -> None:
if "drop" in request.url:
raise IgnoreRequest
crawler = get_crawler(MySpider)
engine = ExecutionEngine(crawler, lambda _: None)
scheduler = TestScheduler() # type: ignore[abstract]
async def start() -> AsyncIterator[Any]:
return
yield
engine._start = start()
engine._slot = _Slot(False, Mock(), scheduler)
crawler.signals.connect(signal_handler, signals.request_scheduled)
keep_request = Request("https://keep.example")
engine._schedule_request(keep_request)
drop_request = Request("https://drop.example")
engine._schedule_request(drop_request)
assert scheduler.enqueued == [keep_request], (
f"{scheduler.enqueued!r} != [{keep_request!r}]"
)
crawler.signals.disconnect(signal_handler, signals.request_scheduled)
class TestEngineCloseSpider:
"""Tests for exception handling coverage during close_spider_async()."""
@pytest.fixture
def crawler(self) -> Crawler:
crawler = get_crawler(DefaultSpider)
crawler.spider = crawler._create_spider()
return crawler
@coroutine_test
async def test_no_slot(self, crawler: Crawler) -> None:
engine = ExecutionEngine(crawler, lambda _: None)
crawler.engine = engine
await engine.open_spider_async()
slot = engine._slot
engine._slot = None
with pytest.raises(RuntimeError, match="Engine slot not assigned"):
await engine.close_spider_async()
# close it correctly
engine._slot = slot
await engine.close_spider_async()
@coroutine_test
async def test_no_spider(self, crawler: Crawler) -> None:
engine = ExecutionEngine(crawler, lambda _: None)
with pytest.raises(RuntimeError, match="Spider not opened"):
await engine.close_spider_async()
engine.downloader.close() # cleanup
@coroutine_test
async def test_exception_slot(
self, crawler: Crawler, caplog: pytest.LogCaptureFixture
) -> None:
engine = ExecutionEngine(crawler, lambda _: None)
crawler.engine = engine
await engine.open_spider_async()
assert engine._slot
del engine._slot.heartbeat
await engine.close_spider_async()
assert "Slot close failure" in caplog.text
@coroutine_test
async def test_exception_downloader(
self, crawler: Crawler, caplog: pytest.LogCaptureFixture
) -> None:
engine = ExecutionEngine(crawler, lambda _: None)
crawler.engine = engine
await engine.open_spider_async()
del engine.downloader.slots
await engine.close_spider_async()
assert "Downloader close failure" in caplog.text
@coroutine_test
async def test_exception_scraper(
self, crawler: Crawler, caplog: pytest.LogCaptureFixture
) -> None:
engine = ExecutionEngine(crawler, lambda _: None)
crawler.engine = engine
await engine.open_spider_async()
engine.scraper.slot = None
await engine.close_spider_async()
assert "Scraper close failure" in caplog.text
@coroutine_test
async def test_exception_scheduler(
self, crawler: Crawler, caplog: pytest.LogCaptureFixture
) -> None:
engine = ExecutionEngine(crawler, lambda _: None)
crawler.engine = engine
await engine.open_spider_async()
assert engine._slot
del cast("Scheduler", engine._slot.scheduler).dqs
await engine.close_spider_async()
assert "Scheduler close failure" in caplog.text
@coroutine_test
async def test_exception_signal(
self, crawler: Crawler, caplog: pytest.LogCaptureFixture
) -> None:
engine = ExecutionEngine(crawler, lambda _: None)
crawler.engine = engine
await engine.open_spider_async()
signal_manager = engine.signals
del engine.signals
await engine.close_spider_async()
assert "Error while sending spider_close signal" in caplog.text
# send the spider_closed signal to close various components
await signal_manager.send_catch_log_async(
signal=signals.spider_closed,
spider=engine.spider,
reason="cancelled",
)
@coroutine_test
async def test_exception_stats(
self, crawler: Crawler, caplog: pytest.LogCaptureFixture
) -> None:
engine = ExecutionEngine(crawler, lambda _: None)
crawler.engine = engine
await engine.open_spider_async()
assert isinstance(crawler.stats, MemoryStatsCollector)
del crawler.stats.spider_stats
await engine.close_spider_async()
assert "Stats close failure" in caplog.text
@coroutine_test
async def test_exception_callback(
self, crawler: Crawler, caplog: pytest.LogCaptureFixture
) -> None:
engine = ExecutionEngine(crawler, lambda _: defer.fail(ValueError()))
crawler.engine = engine
await engine.open_spider_async()
await engine.close_spider_async()
assert "Error running spider_closed_callback" in caplog.text
@coroutine_test
async def test_exception_async_callback(
self, crawler: Crawler, caplog: pytest.LogCaptureFixture
) -> None:
async def cb(_):
raise ValueError
engine = ExecutionEngine(crawler, cb)
crawler.engine = engine
await engine.open_spider_async()
await engine.close_spider_async()
assert "Error running spider_closed_callback" in caplog.text