Do not allow combining crawl_strategy=direct_item with search_queries

tests/test_ecommerce.py

@@ -37,6 +37,19 @@ def test_parameters():
     with pytest.raises(ValidationError):
         EcommerceSpider(url="https://example.com", crawl_strategy="unknown")
 
+    EcommerceSpider(
+        url="https://example.com", crawl_strategy="direct_item", search_queries=""
+    )
+    EcommerceSpider(
+        url="https://example.com", crawl_strategy="automatic", search_queries="foo"
+    )
+    with pytest.raises(ValidationError):
+        EcommerceSpider(
+            url="https://example.com",
+            crawl_strategy="direct_item",
+            search_queries="foo",
+        )
+
 
 def test_start_requests():
     url = "https://example.com"

zyte_spider_templates/spiders/ecommerce.py

@@ -2,7 +2,7 @@
 from typing import Any, Callable, Dict, Iterable, Optional, Union
 
 import scrapy
-from pydantic import BaseModel, ConfigDict, Field
+from pydantic import BaseModel, ConfigDict, Field, model_validator
 from scrapy import Request
 from scrapy.crawler import Crawler
 from scrapy_poet import DummyResponse, DynamicDeps
@@ -142,6 +142,18 @@ class EcommerceCrawlStrategyParam(BaseModel):
         },
     )
 
+    @model_validator(mode="after")
+    def validate_direct_item_and_search_queries(self):
+        if (
+            self.search_queries
+            and self.crawl_strategy == EcommerceCrawlStrategy.direct_item
+        ):
+            raise ValueError(
+                "Cannot combine the direct_item value of the crawl_strategy "
+                "spider parameter with the search_queries spider parameter."
+            )
+        return self
+
 
 class EcommerceSpiderParams(
     CustomAttrsMethodParam,