Fail on SPM + transparent mode

.github/workflows/test.yml

@@ -39,6 +39,11 @@ jobs:
         - python-version: '3.11'
           toxenv: provider
 
+        - python-version: '3.7'
+          toxenv: pinned-extra
+        - python-version: '3.11'
+          toxenv: extra
+
     steps:
     - uses: actions/checkout@v3
     - name: Set up Python ${{ matrix.python-version }}

scrapy_zyte_api/_middlewares.py

@@ -1,5 +1,7 @@
 import logging
+from typing import cast
 
+from scrapy import signals
 from scrapy.exceptions import IgnoreRequest
 from zyte_api.aio.errors import RequestError
 
@@ -32,10 +34,63 @@ def __init__(self, crawler) -> None:
                 f"reached."
             )
 
+        crawler.signals.connect(self.open_spider, signal=signals.spider_opened)
         crawler.signals.connect(
             self._start_requests_processed, signal=_start_requests_processed
         )
 
+    def _get_spm_mw(self):
+        spm_mw_classes = []
+
+        try:
+            from scrapy_crawlera import CrawleraMiddleware
+        except ImportError:
+            pass
+        else:
+            spm_mw_classes.append(CrawleraMiddleware)
+
+        try:
+            from scrapy_zyte_smartproxy import ZyteSmartProxyMiddleware
+        except ImportError:
+            pass
+        else:
+            spm_mw_classes.append(ZyteSmartProxyMiddleware)
+
+        middlewares = self._crawler.engine.downloader.middleware.middlewares
+        for middleware in middlewares:
+            if isinstance(middleware, tuple(spm_mw_classes)):
+                return middleware
+        return None
+
+    def open_spider(self, spider):
+        settings = self._crawler.settings
+        in_transparent_mode = settings.getbool("ZYTE_API_TRANSPARENT_MODE", False)
+        spm_mw = self._get_spm_mw()
+        spm_is_enabled = spm_mw and spm_mw.is_enabled(spider)
+        if not in_transparent_mode or not spm_is_enabled:
+            return
+        logger.error(
+            "Both scrapy-zyte-smartproxy and the transparent mode of "
+            "scrapy-zyte-api are enabled. You should only enable one of "
+            "those at the same time.\n"
+            "\n"
+            "To combine requests that use scrapy-zyte-api and requests "
+            "that use scrapy-zyte-smartproxy in the same spider:\n"
+            "\n"
+            "1. Leave scrapy-zyte-smartproxy enabled.\n"
+            "2. Disable the transparent mode of scrapy-zyte-api.\n"
+            "3. To send a specific request through Zyte API, use "
+            "request.meta to set dont_proxy to True and zyte_api_automap "
+            "either to True or to a dictionary of extra request fields."
+        )
+        from twisted.internet import reactor
+        from twisted.internet.interfaces import IReactorCore
+
+        reactor = cast(IReactorCore, reactor)
+        reactor.callLater(
+            0, self._crawler.engine.close_spider, spider, "plugin_conflict"
+        )
+
     def _start_requests_processed(self, count):
         self._total_start_request_count = count
         self._maybe_close()

tests/test_middlewares.py

@@ -1,3 +1,7 @@
+from typing import Any, Dict, cast
+from unittest import SkipTest
+
+from packaging.version import Version
 from pytest_twisted import ensureDeferred
 from scrapy import Request, Spider
 from scrapy.item import Item
@@ -10,6 +14,10 @@
 from .mockserver import DelayedResource, MockServer
 
 
+class NamedSpider(Spider):
+    name = "named"
+
+
 @ensureDeferred
 async def test_autothrottle_handling():
     crawler = get_crawler()
@@ -259,3 +267,100 @@ def parse(self, response):
         await crawler.crawl()
 
     assert crawler.stats.get_value("finish_reason") == "failed_forbidden_domain"
+
+
+@ensureDeferred
+async def test_spm_conflict_smartproxy():
+    try:
+        import scrapy_zyte_smartproxy  # noqa: F401
+    except ImportError:
+        raise SkipTest("scrapy-zyte-smartproxy missing")
+
+    for setting, attribute, conflict in (
+        (None, None, False),
+        (None, False, False),
+        (None, True, True),
+        (False, None, False),
+        (False, False, False),
+        (False, True, True),
+        (True, None, True),
+        (True, False, False),
+        (True, True, True),
+    ):
+
+        class SPMSpider(Spider):
+            name = "spm_spider"
+
+        if attribute is not None:
+            SPMSpider.zyte_smartproxy_enabled = attribute
+
+        settings = {
+            "ZYTE_API_TRANSPARENT_MODE": True,
+            "ZYTE_SMARTPROXY_APIKEY": "foo",
+            **SETTINGS,
+        }
+        mws = dict(cast(Dict[Any, int], settings["DOWNLOADER_MIDDLEWARES"]))
+        mws["scrapy_zyte_smartproxy.ZyteSmartProxyMiddleware"] = 610
+        settings["DOWNLOADER_MIDDLEWARES"] = mws
+
+        if setting is not None:
+            settings["ZYTE_SMARTPROXY_ENABLED"] = setting
+
+        crawler = get_crawler(SPMSpider, settings_dict=settings)
+        await crawler.crawl()
+        expected = "plugin_conflict" if conflict else "finished"
+        assert crawler.stats.get_value("finish_reason") == expected, (
+            setting,
+            attribute,
+            conflict,
+        )
+
+
+@ensureDeferred
+async def test_spm_conflict_crawlera():
+    try:
+        import scrapy_crawlera  # noqa: F401
+    except ImportError:
+        raise SkipTest("scrapy-crawlera missing")
+    else:
+        SCRAPY_CRAWLERA_VERSION = Version(scrapy_crawlera.__version__)
+
+    for setting, attribute, conflict in (
+        (None, None, False),
+        (None, False, False),
+        (None, True, True),
+        (False, None, False),
+        (False, False, False),
+        (False, True, True),
+        (True, None, True),
+        # https://github.com/scrapy-plugins/scrapy-zyte-smartproxy/commit/49ebedd8b1d48cf2667db73f18da3e2c2c7fbfa7
+        (True, False, SCRAPY_CRAWLERA_VERSION < Version("1.7")),
+        (True, True, True),
+    ):
+
+        class CrawleraSpider(Spider):
+            name = "crawlera_spider"
+
+        if attribute is not None:
+            CrawleraSpider.crawlera_enabled = attribute
+
+        settings = {
+            "ZYTE_API_TRANSPARENT_MODE": True,
+            "CRAWLERA_APIKEY": "foo",
+            **SETTINGS,
+        }
+        mws = dict(cast(Dict[Any, int], settings["DOWNLOADER_MIDDLEWARES"]))
+        mws["scrapy_crawlera.CrawleraMiddleware"] = 610
+        settings["DOWNLOADER_MIDDLEWARES"] = mws
+
+        if setting is not None:
+            settings["CRAWLERA_ENABLED"] = setting
+
+        crawler = get_crawler(CrawleraSpider, settings_dict=settings)
+        await crawler.crawl()
+        expected = "plugin_conflict" if conflict else "finished"
+        assert crawler.stats.get_value("finish_reason") == expected, (
+            setting,
+            attribute,
+            conflict,
+        )

tox.ini

@@ -92,6 +92,20 @@ deps =
     web-poet==0.13.0
     zyte-common-items==0.7.0
 
+[testenv:pinned-extra]
+basepython=python3.7
+deps =
+    {[testenv:pinned-scrapy-2x0]deps}
+    scrapy-crawlera==1.1.0
+    scrapy-zyte-smartproxy==2.0.0
+
+[testenv:extra]
+basepython=python3.11
+deps =
+    {[testenv]deps}
+    scrapy-crawlera
+    scrapy-zyte-smartproxy
+
 [testenv:mypy]
 deps =
     mypy==1.4.1