Files
Scrapling/tests/spiders/test_engine.py
T
Abdullah a86e9709ea feat(spiders): pre-warm robots.txt cache before crawl loop starts
Previously robots.txt was fetched lazily on the first request per
domain, causing early concurrent requests to each stall waiting for
the same network fetch. The cache is now warmed before the crawl loop
starts, making all subsequent robots.txt lookups a local read.

- RobotsTxtManager gains a prefetch(urls, sid) method that fetches all domains concurrently via a task group
- CrawlerEngine._prefetch_robots_txt() is called after on_start():
  uses allowed_domains if configured, otherwise falls back to unique
  domains extracted from start_urls
- Mid-crawl domain discovery (not covered by prefetch) still fetches
  lazily; two concurrent callbacks on the same new domain can each
  trigger a fetch — accepted tradeoff, documented in _get_domain_delay

Files: scrapling/spiders/robotstxt.py, scrapling/spiders/engine.py, tests/spiders/test_engine.py
2026-04-04 03:00:15 +02:00

1001 lines
34 KiB
Python

"""Tests for the CrawlerEngine class."""
import tempfile
from pathlib import Path
import anyio
import pytest
from scrapling.spiders.engine import CrawlerEngine, _dump
from scrapling.spiders.request import Request
from scrapling.spiders.robotstxt import RobotsTxtManager
from scrapling.spiders.session import SessionManager
from scrapling.spiders.result import CrawlStats, ItemList
from scrapling.spiders.checkpoint import CheckpointData
from scrapling.core._types import Any, Dict, Set, AsyncGenerator
# ---------------------------------------------------------------------------
# Mock helpers
# ---------------------------------------------------------------------------
class MockResponse:
"""Minimal Response stand-in."""
def __init__(self, status: int = 200, body: bytes = b"ok", url: str = "https://example.com", encoding: str = "utf-8"):
self.status = status
self.body = body
self.url = url
self.encoding = encoding
self.request: Any = None
self.meta: Dict[str, Any] = {}
def __str__(self) -> str:
return self.url
class MockSession:
"""Mock session that returns a canned response."""
def __init__(self, name: str = "mock", response: MockResponse | None = None):
self.name = name
self._is_alive = False
self._response = response or MockResponse()
self.fetch_calls: list[dict] = []
async def __aenter__(self):
self._is_alive = True
return self
async def __aexit__(self, *args):
self._is_alive = False
async def fetch(self, url: str, **kwargs):
self.fetch_calls.append({"url": url, **kwargs})
resp = MockResponse(status=self._response.status, body=self._response.body, url=url)
return resp
class ErrorSession(MockSession):
"""Session that raises on fetch."""
def __init__(self, error: Exception | None = None):
super().__init__("error")
self._error = error or RuntimeError("fetch failed")
async def fetch(self, url: str, **kwargs):
raise self._error
class MockSpider:
"""Lightweight spider stub for engine tests."""
def __init__(
self,
*,
concurrent_requests: int = 4,
concurrent_requests_per_domain: int = 0,
download_delay: float = 0.0,
max_blocked_retries: int = 3,
allowed_domains: Set[str] | None = None,
fp_include_kwargs: bool = False,
fp_include_headers: bool = False,
fp_keep_fragments: bool = False,
is_blocked_fn=None,
on_scraped_item_fn=None,
retry_blocked_request_fn=None,
robots_txt_obey: bool = False,
start_urls: list[str] | None = None,
):
self.concurrent_requests = concurrent_requests
self.concurrent_requests_per_domain = concurrent_requests_per_domain
self.download_delay = download_delay
self.max_blocked_retries = max_blocked_retries
self.allowed_domains = allowed_domains or set()
self.fp_include_kwargs = fp_include_kwargs
self.fp_include_headers = fp_include_headers
self.fp_keep_fragments = fp_keep_fragments
self.name = "test_spider"
self.robots_txt_obey = robots_txt_obey
self.start_urls = start_urls or []
# Tracking lists
self.on_start_calls: list[dict] = []
self.on_close_calls: int = 0
self.on_error_calls: list[tuple[Request, Exception]] = []
self.scraped_items: list[dict] = []
self.blocked_responses: list = []
self.retry_requests: list = []
# Pluggable behaviour
self._is_blocked_fn = is_blocked_fn
self._on_scraped_item_fn = on_scraped_item_fn
self._retry_blocked_request_fn = retry_blocked_request_fn
# Log counter stub
self._log_counter = _LogCounterStub()
async def parse(self, response) -> AsyncGenerator[Dict[str, Any] | Request | None, None]:
yield {"url": str(response)}
async def on_start(self, resuming: bool = False) -> None:
self.on_start_calls.append({"resuming": resuming})
async def on_close(self) -> None:
self.on_close_calls += 1
async def on_error(self, request: Request, error: Exception) -> None:
self.on_error_calls.append((request, error))
async def on_scraped_item(self, item: Dict[str, Any]) -> Dict[str, Any] | None:
if self._on_scraped_item_fn:
return self._on_scraped_item_fn(item)
self.scraped_items.append(item)
return item
async def is_blocked(self, response) -> bool:
if self._is_blocked_fn:
return self._is_blocked_fn(response)
return False
async def retry_blocked_request(self, request: Request, response) -> Request:
self.retry_requests.append(request)
if self._retry_blocked_request_fn:
return self._retry_blocked_request_fn(request, response)
return request
async def start_requests(self) -> AsyncGenerator[Request, None]:
yield Request("https://example.com", sid="default")
class _LogCounterStub:
"""Stub for LogCounterHandler."""
def get_counts(self) -> Dict[str, int]:
return {"debug": 0, "info": 0, "warning": 0, "error": 0, "critical": 0}
def _make_engine(
spider: MockSpider | None = None,
session: MockSession | None = None,
crawldir: str | None = None,
interval: float = 300.0,
) -> CrawlerEngine:
"""Create a CrawlerEngine wired to mock objects."""
spider = spider or MockSpider()
sm = SessionManager()
sm.add("default", session or MockSession())
return CrawlerEngine(spider, sm, crawldir=crawldir, interval=interval)
# ---------------------------------------------------------------------------
# Tests: _dump helper
# ---------------------------------------------------------------------------
class TestDumpHelper:
def test_dump_returns_json_string(self):
result = _dump({"key": "value"})
assert '"key": "value"' in result
def test_dump_handles_nested(self):
result = _dump({"a": {"b": 1}})
assert '"a"' in result
assert '"b"' in result
# ---------------------------------------------------------------------------
# Tests: __init__
# ---------------------------------------------------------------------------
class TestCrawlerEngineInit:
def test_default_initialisation(self):
engine = _make_engine()
assert engine._running is False
assert engine._active_tasks == 0
assert engine._pause_requested is False
assert engine._force_stop is False
assert engine.paused is False
assert isinstance(engine.stats, CrawlStats)
assert isinstance(engine.items, ItemList)
def test_checkpoint_system_disabled_by_default(self):
engine = _make_engine()
assert engine._checkpoint_system_enabled is False
def test_checkpoint_system_enabled_with_crawldir(self):
with tempfile.TemporaryDirectory() as tmpdir:
engine = _make_engine(crawldir=tmpdir)
assert engine._checkpoint_system_enabled is True
def test_global_limiter_uses_concurrent_requests(self):
spider = MockSpider(concurrent_requests=8)
engine = _make_engine(spider=spider)
assert engine._global_limiter.total_tokens == 8
def test_allowed_domains_from_spider(self):
spider = MockSpider(allowed_domains={"example.com", "test.org"})
engine = _make_engine(spider=spider)
assert engine._allowed_domains == {"example.com", "test.org"}
# ---------------------------------------------------------------------------
# Tests: _is_domain_allowed
# ---------------------------------------------------------------------------
class TestIsDomainAllowed:
def test_all_allowed_when_empty(self):
engine = _make_engine()
request = Request("https://anything.com/page")
assert engine._is_domain_allowed(request) is True
def test_exact_domain_match(self):
spider = MockSpider(allowed_domains={"example.com"})
engine = _make_engine(spider=spider)
assert engine._is_domain_allowed(Request("https://example.com/page")) is True
assert engine._is_domain_allowed(Request("https://other.com/page")) is False
def test_subdomain_match(self):
spider = MockSpider(allowed_domains={"example.com"})
engine = _make_engine(spider=spider)
assert engine._is_domain_allowed(Request("https://sub.example.com/page")) is True
assert engine._is_domain_allowed(Request("https://deep.sub.example.com/x")) is True
def test_partial_name_not_matched(self):
spider = MockSpider(allowed_domains={"example.com"})
engine = _make_engine(spider=spider)
# "notexample.com" should NOT match "example.com"
assert engine._is_domain_allowed(Request("https://notexample.com/x")) is False
def test_multiple_allowed_domains(self):
spider = MockSpider(allowed_domains={"a.com", "b.org"})
engine = _make_engine(spider=spider)
assert engine._is_domain_allowed(Request("https://a.com/")) is True
assert engine._is_domain_allowed(Request("https://b.org/")) is True
assert engine._is_domain_allowed(Request("https://c.net/")) is False
# ---------------------------------------------------------------------------
# Tests: _rate_limiter
# ---------------------------------------------------------------------------
class TestRateLimiter:
def test_returns_global_limiter_when_per_domain_disabled(self):
engine = _make_engine() # concurrent_requests_per_domain=0
limiter = engine._rate_limiter("example.com")
assert limiter is engine._global_limiter
def test_returns_per_domain_limiter_when_enabled(self):
spider = MockSpider(concurrent_requests_per_domain=2)
engine = _make_engine(spider=spider)
limiter = engine._rate_limiter("example.com")
assert limiter is not engine._global_limiter
assert limiter.total_tokens == 2
def test_same_domain_returns_same_limiter(self):
spider = MockSpider(concurrent_requests_per_domain=2)
engine = _make_engine(spider=spider)
l1 = engine._rate_limiter("example.com")
l2 = engine._rate_limiter("example.com")
assert l1 is l2
def test_different_domains_get_different_limiters(self):
spider = MockSpider(concurrent_requests_per_domain=2)
engine = _make_engine(spider=spider)
l1 = engine._rate_limiter("a.com")
l2 = engine._rate_limiter("b.com")
assert l1 is not l2
# ---------------------------------------------------------------------------
# Tests: _normalize_request
# ---------------------------------------------------------------------------
class TestNormalizeRequest:
def test_sets_default_sid_when_empty(self):
engine = _make_engine()
request = Request("https://example.com")
assert request.sid == ""
engine._normalize_request(request)
assert request.sid == "default"
def test_preserves_existing_sid(self):
engine = _make_engine()
request = Request("https://example.com", sid="custom")
engine._normalize_request(request)
assert request.sid == "custom"
# ---------------------------------------------------------------------------
# Tests: _process_request
# ---------------------------------------------------------------------------
class TestProcessRequest:
@pytest.mark.asyncio
async def test_successful_fetch_updates_stats(self):
spider = MockSpider()
session = MockSession(response=MockResponse(status=200, body=b"hello"))
engine = _make_engine(spider=spider, session=session)
request = Request("https://example.com", sid="default")
await engine._process_request(request)
assert engine.stats.requests_count == 1
assert engine.stats.response_bytes == 5 # len(b"hello") from MockSession
assert "status_200" in engine.stats.response_status_count
@pytest.mark.asyncio
async def test_failed_fetch_increments_failed_count(self):
spider = MockSpider()
sm = SessionManager()
sm.add("default", ErrorSession())
engine = CrawlerEngine(spider, sm)
request = Request("https://example.com", sid="default")
await engine._process_request(request)
assert engine.stats.failed_requests_count == 1
assert len(spider.on_error_calls) == 1
@pytest.mark.asyncio
async def test_failed_fetch_does_not_increment_requests_count(self):
spider = MockSpider()
sm = SessionManager()
sm.add("default", ErrorSession())
engine = CrawlerEngine(spider, sm)
request = Request("https://example.com", sid="default")
await engine._process_request(request)
assert engine.stats.requests_count == 0
@pytest.mark.asyncio
async def test_blocked_response_triggers_retry(self):
spider = MockSpider(is_blocked_fn=lambda r: True, max_blocked_retries=2)
engine = _make_engine(spider=spider)
request = Request("https://example.com", sid="default")
await engine._process_request(request)
assert engine.stats.blocked_requests_count == 1
# A retry request should be enqueued
assert not engine.scheduler.is_empty
@pytest.mark.asyncio
async def test_blocked_response_max_retries_exceeded(self):
spider = MockSpider(is_blocked_fn=lambda r: True, max_blocked_retries=2)
engine = _make_engine(spider=spider)
request = Request("https://example.com", sid="default")
request._retry_count = 2 # Already at max
await engine._process_request(request)
assert engine.stats.blocked_requests_count == 1
# No retry enqueued
assert engine.scheduler.is_empty
@pytest.mark.asyncio
async def test_retry_request_has_dont_filter(self):
spider = MockSpider(is_blocked_fn=lambda r: True, max_blocked_retries=3)
engine = _make_engine(spider=spider)
request = Request("https://example.com", sid="default")
await engine._process_request(request)
retry = await engine.scheduler.dequeue()
assert retry.dont_filter is True
assert retry._retry_count == 1
@pytest.mark.asyncio
async def test_retry_clears_proxy_kwargs(self):
spider = MockSpider(is_blocked_fn=lambda r: True, max_blocked_retries=3)
engine = _make_engine(spider=spider)
request = Request("https://example.com", sid="default", proxy="http://proxy:8080")
await engine._process_request(request)
retry = await engine.scheduler.dequeue()
assert "proxy" not in retry._session_kwargs
assert "proxies" not in retry._session_kwargs
@pytest.mark.asyncio
async def test_callback_yielding_dict_increments_items(self):
spider = MockSpider()
engine = _make_engine(spider=spider)
request = Request("https://example.com", sid="default")
await engine._process_request(request)
assert engine.stats.items_scraped == 1
assert len(engine.items) == 1
@pytest.mark.asyncio
async def test_callback_yielding_request_enqueues(self):
async def callback(response) -> AsyncGenerator:
yield Request("https://example.com/page2", sid="default")
spider = MockSpider()
engine = _make_engine(spider=spider)
request = Request("https://example.com", sid="default", callback=callback)
await engine._process_request(request)
assert not engine.scheduler.is_empty
@pytest.mark.asyncio
async def test_callback_yielding_offsite_request_filtered(self):
async def callback(response) -> AsyncGenerator:
yield Request("https://other.com/page", sid="default")
spider = MockSpider(allowed_domains={"example.com"})
engine = _make_engine(spider=spider)
request = Request("https://example.com", sid="default", callback=callback)
await engine._process_request(request)
assert engine.stats.offsite_requests_count == 1
assert engine.scheduler.is_empty
@pytest.mark.asyncio
async def test_dropped_item_when_on_scraped_item_returns_none(self):
spider = MockSpider(on_scraped_item_fn=lambda item: None)
engine = _make_engine(spider=spider)
request = Request("https://example.com", sid="default")
await engine._process_request(request)
assert engine.stats.items_dropped == 1
assert engine.stats.items_scraped == 0
assert len(engine.items) == 0
@pytest.mark.asyncio
async def test_callback_exception_calls_on_error(self):
async def bad_callback(response) -> AsyncGenerator:
raise ValueError("callback boom")
yield # noqa: unreachable
spider = MockSpider()
engine = _make_engine(spider=spider)
request = Request("https://example.com", sid="default", callback=bad_callback)
await engine._process_request(request)
assert len(spider.on_error_calls) == 1
assert isinstance(spider.on_error_calls[0][1], ValueError)
@pytest.mark.asyncio
async def test_proxy_tracked_in_stats(self):
spider = MockSpider()
engine = _make_engine(spider=spider)
request = Request("https://example.com", sid="default", proxy="http://p:8080")
await engine._process_request(request)
assert "http://p:8080" in engine.stats.proxies
@pytest.mark.asyncio
async def test_proxies_dict_tracked_in_stats(self):
spider = MockSpider()
engine = _make_engine(spider=spider)
proxies = {"http": "http://p:8080", "https": "https://p:8443"}
request = Request("https://example.com", sid="default", proxies=proxies)
await engine._process_request(request)
assert len(engine.stats.proxies) == 1
assert engine.stats.proxies[0] == proxies
@pytest.mark.asyncio
async def test_uses_parse_when_no_callback(self):
items_seen = []
async def custom_parse(response) -> AsyncGenerator:
yield {"from": "custom_parse"}
spider = MockSpider()
spider.parse = custom_parse # type: ignore[assignment]
engine = _make_engine(spider=spider)
request = Request("https://example.com", sid="default")
# No callback set → should use spider.parse
await engine._process_request(request)
assert engine.stats.items_scraped == 1
# ---------------------------------------------------------------------------
# Tests: _task_wrapper
# ---------------------------------------------------------------------------
class TestTaskWrapper:
@pytest.mark.asyncio
async def test_decrements_active_tasks(self):
engine = _make_engine()
engine._active_tasks = 1
request = Request("https://example.com", sid="default")
await engine._task_wrapper(request)
assert engine._active_tasks == 0
@pytest.mark.asyncio
async def test_decrements_even_on_error(self):
spider = MockSpider()
sm = SessionManager()
sm.add("default", ErrorSession())
engine = CrawlerEngine(spider, sm)
engine._active_tasks = 1
request = Request("https://example.com", sid="default")
await engine._task_wrapper(request)
assert engine._active_tasks == 0
# ---------------------------------------------------------------------------
# Tests: request_pause
# ---------------------------------------------------------------------------
class TestRequestPause:
def test_first_call_sets_pause_requested(self):
engine = _make_engine()
engine.request_pause()
assert engine._pause_requested is True
assert engine._force_stop is False
def test_second_call_sets_force_stop(self):
engine = _make_engine()
engine.request_pause() # first
engine.request_pause() # second
assert engine._pause_requested is True
assert engine._force_stop is True
def test_third_call_after_force_stop_is_noop(self):
engine = _make_engine()
engine.request_pause()
engine.request_pause()
engine.request_pause() # should not raise
assert engine._force_stop is True
# ---------------------------------------------------------------------------
# Tests: checkpoint methods
# ---------------------------------------------------------------------------
class TestCheckpointMethods:
def test_is_checkpoint_time_false_when_disabled(self):
engine = _make_engine() # no crawldir
assert engine._is_checkpoint_time() is False
@pytest.mark.asyncio
async def test_save_and_restore_checkpoint(self):
with tempfile.TemporaryDirectory() as tmpdir:
spider = MockSpider()
engine = _make_engine(spider=spider, crawldir=tmpdir)
# Enqueue a request so snapshot has data
req = Request("https://example.com", sid="default")
engine._normalize_request(req)
await engine.scheduler.enqueue(req)
await engine._save_checkpoint()
# Verify checkpoint file exists
checkpoint_path = Path(tmpdir) / "checkpoint.pkl"
assert checkpoint_path.exists()
@pytest.mark.asyncio
async def test_restore_when_no_checkpoint_returns_false(self):
with tempfile.TemporaryDirectory() as tmpdir:
engine = _make_engine(crawldir=tmpdir)
result = await engine._restore_from_checkpoint()
assert result is False
@pytest.mark.asyncio
async def test_restore_from_checkpoint_raises_when_disabled(self):
engine = _make_engine() # no crawldir → checkpoint disabled
assert (await engine._restore_from_checkpoint()) is False
# ---------------------------------------------------------------------------
# Tests: crawl
# ---------------------------------------------------------------------------
class TestCrawl:
@pytest.mark.asyncio
async def test_basic_crawl_returns_stats(self):
spider = MockSpider()
engine = _make_engine(spider=spider)
stats = await engine.crawl()
assert isinstance(stats, CrawlStats)
assert stats.requests_count >= 1
assert stats.items_scraped >= 1
@pytest.mark.asyncio
async def test_crawl_calls_on_start_and_on_close(self):
spider = MockSpider()
engine = _make_engine(spider=spider)
await engine.crawl()
assert len(spider.on_start_calls) == 1
assert spider.on_start_calls[0]["resuming"] is False
assert spider.on_close_calls == 1
@pytest.mark.asyncio
async def test_crawl_sets_stats_timing(self):
spider = MockSpider()
engine = _make_engine(spider=spider)
stats = await engine.crawl()
assert stats.start_time > 0
assert stats.end_time > 0
assert stats.end_time >= stats.start_time
@pytest.mark.asyncio
async def test_crawl_sets_concurrency_stats(self):
spider = MockSpider(concurrent_requests=16, concurrent_requests_per_domain=4)
engine = _make_engine(spider=spider)
stats = await engine.crawl()
assert stats.concurrent_requests == 16
assert stats.concurrent_requests_per_domain == 4
@pytest.mark.asyncio
async def test_crawl_processes_multiple_start_urls(self):
spider = MockSpider()
urls = ["https://example.com/1", "https://example.com/2", "https://example.com/3"]
async def multi_start_requests() -> AsyncGenerator[Request, None]:
for url in urls:
yield Request(url, sid="default")
spider.start_requests = multi_start_requests # type: ignore[assignment]
engine = _make_engine(spider=spider)
stats = await engine.crawl()
assert stats.requests_count == 3
assert stats.items_scraped == 3
@pytest.mark.asyncio
async def test_crawl_follows_yielded_requests(self):
"""Test that requests yielded from callbacks are processed."""
call_count = 0
async def parse_with_follow(response) -> AsyncGenerator:
nonlocal call_count
call_count += 1
if call_count == 1:
yield Request("https://example.com/page2", sid="default")
yield {"page": str(response)}
spider = MockSpider()
spider.parse = parse_with_follow # type: ignore[assignment]
engine = _make_engine(spider=spider)
stats = await engine.crawl()
assert stats.requests_count == 2
assert stats.items_scraped == 2
@pytest.mark.asyncio
async def test_crawl_with_download_delay(self):
spider = MockSpider(download_delay=0.01)
engine = _make_engine(spider=spider)
stats = await engine.crawl()
assert stats.download_delay == 0.01
assert stats.requests_count >= 1
@pytest.mark.asyncio
async def test_crawl_filters_offsite_requests(self):
async def parse_offsite(response) -> AsyncGenerator:
yield Request("https://other-domain.com/page", sid="default")
yield {"url": str(response)}
spider = MockSpider(allowed_domains={"example.com"})
spider.parse = parse_offsite # type: ignore[assignment]
engine = _make_engine(spider=spider)
stats = await engine.crawl()
assert stats.offsite_requests_count == 1
assert stats.requests_count == 1 # Only the initial request
@pytest.mark.asyncio
async def test_crawl_cleans_up_checkpoint_on_completion(self):
with tempfile.TemporaryDirectory() as tmpdir:
spider = MockSpider()
engine = _make_engine(spider=spider, crawldir=tmpdir)
await engine.crawl()
checkpoint_path = Path(tmpdir) / "checkpoint.pkl"
assert not checkpoint_path.exists() # Cleaned up
@pytest.mark.asyncio
async def test_crawl_handles_fetch_error_gracefully(self):
spider = MockSpider()
sm = SessionManager()
sm.add("default", ErrorSession())
engine = CrawlerEngine(spider, sm)
stats = await engine.crawl()
assert stats.failed_requests_count == 1
assert len(spider.on_error_calls) == 1
@pytest.mark.asyncio
async def test_crawl_log_levels_populated(self):
spider = MockSpider()
engine = _make_engine(spider=spider)
stats = await engine.crawl()
assert isinstance(stats.log_levels_counter, dict)
@pytest.mark.asyncio
async def test_crawl_resets_state_on_each_run(self):
spider = MockSpider()
engine = _make_engine(spider=spider)
# Run first crawl
await engine.crawl()
assert engine.stats.requests_count >= 1
# Run second crawl - stats should reset
stats = await engine.crawl()
# Items are cleared on each crawl
assert engine.paused is False
# ---------------------------------------------------------------------------
# Tests: items property
# ---------------------------------------------------------------------------
class TestItemsProperty:
def test_items_returns_item_list(self):
engine = _make_engine()
assert isinstance(engine.items, ItemList)
def test_items_initially_empty(self):
engine = _make_engine()
assert len(engine.items) == 0
@pytest.mark.asyncio
async def test_items_populated_after_crawl(self):
engine = _make_engine()
await engine.crawl()
assert len(engine.items) >= 1
# ---------------------------------------------------------------------------
# Tests: streaming (__aiter__ / _stream)
# ---------------------------------------------------------------------------
class TestStreaming:
@pytest.mark.asyncio
async def test_stream_yields_items(self):
spider = MockSpider()
engine = _make_engine(spider=spider)
items = []
async for item in engine:
items.append(item)
assert len(items) >= 1
assert isinstance(items[0], dict)
@pytest.mark.asyncio
async def test_stream_processes_follow_up_requests(self):
call_count = 0
async def parse_with_follow(response) -> AsyncGenerator:
nonlocal call_count
call_count += 1
if call_count == 1:
yield Request("https://example.com/page2", sid="default")
yield {"page": call_count}
spider = MockSpider()
spider.parse = parse_with_follow # type: ignore[assignment]
engine = _make_engine(spider=spider)
items = []
async for item in engine:
items.append(item)
assert len(items) == 2
@pytest.mark.asyncio
async def test_stream_items_not_stored_in_items_list(self):
"""When streaming, items go to the stream, not to engine._items."""
spider = MockSpider()
engine = _make_engine(spider=spider)
items = []
async for item in engine:
items.append(item)
# Items were sent through stream, not appended to _items
assert len(items) >= 1
assert len(engine.items) == 0
# ---------------------------------------------------------------------------
# Tests: pause during crawl
# ---------------------------------------------------------------------------
class TestPauseDuringCrawl:
@pytest.mark.asyncio
async def test_pause_stops_crawl_gracefully(self):
processed = 0
async def slow_parse(response) -> AsyncGenerator:
nonlocal processed
processed += 1
# Yield more requests to keep the crawl going
if processed <= 2:
yield Request(f"https://example.com/p{processed + 1}", sid="default")
yield {"n": processed}
spider = MockSpider()
spider.parse = slow_parse # type: ignore[assignment]
engine = _make_engine(spider=spider)
# Request pause immediately - the engine will stop as soon as active tasks complete
engine._pause_requested = True
stats = await engine.crawl()
# Should stop without processing everything
assert engine._running is False
@pytest.mark.asyncio
async def test_pause_with_checkpoint_sets_paused(self):
with tempfile.TemporaryDirectory() as tmpdir:
parse_count = 0
async def parse_and_pause(response) -> AsyncGenerator:
nonlocal parse_count
parse_count += 1
# Request pause after first request, but yield follow-ups
if parse_count == 1:
engine.request_pause()
yield Request("https://example.com/p2", sid="default")
yield {"n": parse_count}
spider = MockSpider()
spider.parse = parse_and_pause # type: ignore[assignment]
engine = _make_engine(spider=spider, crawldir=tmpdir)
await engine.crawl()
assert engine.paused is True
@pytest.mark.asyncio
async def test_pause_without_checkpoint_does_not_set_paused(self):
spider = MockSpider()
engine = _make_engine(spider=spider)
engine._pause_requested = True
await engine.crawl()
assert engine.paused is False
# ---------------------------------------------------------------------------
# Tests: _prefetch_robots_txt
# ---------------------------------------------------------------------------
class TestPrefetchRobotsTxt:
"""_prefetch_robots_txt warms the robots.txt cache before the crawl loop."""
@staticmethod
def _make_counting_fetch():
"""Return (fetch_fn, calls_list) where calls_list records every (url, sid) pair."""
calls: list[tuple[str, str]] = []
async def _fetch(url: str, sid: str):
calls.append((url, sid))
return MockResponse(status=200, body=b"", url=url)
return _fetch, calls
@pytest.mark.asyncio
async def test_prefetch_uses_allowed_domains_when_set(self):
fetch_fn, calls = self._make_counting_fetch()
spider = MockSpider(allowed_domains={"a.com", "b.com"}, robots_txt_obey=True)
engine = _make_engine(spider=spider)
engine._robots_manager = RobotsTxtManager(fetch_fn)
await engine._prefetch_robots_txt()
fetched_domains = {Request(url).domain for url, _ in calls}
assert fetched_domains == {"a.com", "b.com"}
@pytest.mark.asyncio
async def test_prefetch_falls_back_to_start_urls_when_no_allowed_domains(self):
fetch_fn, calls = self._make_counting_fetch()
spider = MockSpider(robots_txt_obey=True, start_urls=["https://example.com/page1"])
engine = _make_engine(spider=spider)
engine._robots_manager = RobotsTxtManager(fetch_fn)
await engine._prefetch_robots_txt()
assert len(calls) == 1
assert calls[0][0] == "https://example.com/robots.txt"
@pytest.mark.asyncio
async def test_prefetch_noop_when_robots_disabled(self):
fetch_fn, calls = self._make_counting_fetch()
spider = MockSpider(robots_txt_obey=False)
engine = _make_engine(spider=spider)
assert engine._robots_manager is None
await engine._prefetch_robots_txt()
assert calls == []
@pytest.mark.asyncio
async def test_prefetch_noop_when_start_urls_empty(self):
fetch_fn, calls = self._make_counting_fetch()
spider = MockSpider(robots_txt_obey=True, start_urls=[])
engine = _make_engine(spider=spider)
engine._robots_manager = RobotsTxtManager(fetch_fn)
await engine._prefetch_robots_txt()
assert calls == []
@pytest.mark.asyncio
async def test_prefetch_deduplicates_same_domain_in_start_urls(self):
fetch_fn, calls = self._make_counting_fetch()
spider = MockSpider(robots_txt_obey=True, start_urls=["https://example.com/a", "https://example.com/b"])
engine = _make_engine(spider=spider)
engine._robots_manager = RobotsTxtManager(fetch_fn)
await engine._prefetch_robots_txt()
# set of Request.domain values deduplicates to one task per domain
assert len(calls) == 1
assert calls[0][0] == "https://example.com/robots.txt"