change crawler_process to optional

scrapy/commands/__init__.py

@@ -4,9 +4,10 @@ Base class for Scrapy commands
 import os
 import argparse
 from pathlib import Path
-from typing import Any, Dict
+from typing import Any, Dict, Optional
 
 from twisted.python import failure
+from scrapy.crawler import CrawlerProcess
 
 from scrapy.utils.conf import arglist_to_dict, feed_process_params_from_cli
 from scrapy.exceptions import UsageError
@@ -15,7 +16,7 @@ from scrapy.exceptions import UsageError
 class ScrapyCommand:
 
     requires_project = False
-    crawler_process: Any = None
+    crawler_process: Optional[CrawlerProcess] = None
 
     # default settings to be used for this command instead of global defaults
     default_settings: Dict[str, Any] = {}

scrapy/commands/genspider.py

@@ -133,6 +133,10 @@ class Command(ScrapyCommand):
                 return True
             return False
 
+        assert (
+            self.crawler_process is not None
+        ), "crawler_process must be set before calling run"
+
         try:
             spidercls = self.crawler_process.spider_loader.load(name)
         except KeyError: