Add checkpoint logic and tests

tests/test_scraper.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import unittest
+from types import SimpleNamespace
 from unittest.mock import MagicMock
 
 from iaai_scraper.core.config import Settings
@@ -169,6 +170,50 @@ class TestScraperSync(unittest.TestCase):
         self.assertTrue(IAAIScraper._is_protection_or_network_error(RuntimeError("captcha challenge")))
         self.assertFalse(IAAIScraper._is_protection_or_network_error(RuntimeError("plain validation error")))
 
+    def test_recover_empty_listing_page_reload_recovers_links(self) -> None:
+        scraper = self._make_scraper()
+        page = MagicMock()
+        page_result = SimpleNamespace(
+            vehicle_links=[SimpleNamespace(href="https://www.iaai.com/VehicleDetail/123~US")],
+        )
+        scraper.listing_collector.collect_current_page = MagicMock(return_value=page_result)
+
+        all_raw_urls: list[str] = []
+        seen_urls: set[str] = set()
+
+        recovered_result, recovered_urls = scraper._recover_empty_listing_page(
+            page,
+            page_number=5,
+            all_raw_urls=all_raw_urls,
+            seen_urls=seen_urls,
+        )
+
+        page.reload.assert_called_once()
+        self.assertIs(recovered_result, page_result)
+        self.assertEqual(recovered_urls, ["https://www.iaai.com/VehicleDetail/123~US"])
+        self.assertEqual(all_raw_urls, ["https://www.iaai.com/VehicleDetail/123~US"])
+
+    def test_recover_empty_listing_page_reopens_listing_for_first_page(self) -> None:
+        scraper = self._make_scraper()
+        page = MagicMock()
+        page_result = SimpleNamespace(
+            vehicle_links=[SimpleNamespace(href="https://www.iaai.com/VehicleDetail/456~US")],
+        )
+        scraper.listing_collector.open_cars_listing = MagicMock()
+        scraper.listing_collector.collect_current_page = MagicMock(return_value=page_result)
+
+        recovered_result, recovered_urls = scraper._recover_empty_listing_page(
+            page,
+            page_number=1,
+            all_raw_urls=[],
+            seen_urls=set(),
+        )
+
+        scraper.listing_collector.open_cars_listing.assert_called_once_with(page)
+        page.reload.assert_not_called()
+        self.assertIs(recovered_result, page_result)
+        self.assertEqual(recovered_urls, ["https://www.iaai.com/VehicleDetail/456~US"])
+
 
 if __name__ == "__main__":
     unittest.main()