Avoid self-link suggestions for redirect targets

test_web_view.py

@@ -55,6 +55,61 @@ class ArticlePageSkipTests(unittest.TestCase):
         )
         self.assertIn("Useful candidate", body)
 
+    def test_redirect_target_is_left_out_of_candidates(self) -> None:
+        hits = [
+            hit("Documentary film"),
+            hit("Useful candidate"),
+        ]
+
+        with (
+            patch("web_view.api.get_wiki_info", return_value="Documentary film"),
+            patch("web_view.search_count", return_value=2),
+            patch("web_view.search_count_with_link", return_value=0),
+            patch("web_view.search_no_link", return_value=(2, hits)),
+        ):
+            response = self.client.get("/link/DVD_documentary")
+
+        body = response.get_data(as_text=True)
+        self.assertEqual(response.status_code, 200)
+        self.assertNotIn('data-title="Documentary film"', body)
+        self.assertIn("Useful candidate", body)
+
+    def test_redirect_target_case_variant_is_left_out_of_candidates(self) -> None:
+        hits = [hit("documentary film")]
+
+        with (
+            patch("web_view.api.get_wiki_info", return_value="Documentary film"),
+            patch("web_view.search_count", return_value=1),
+            patch("web_view.search_count_with_link", return_value=0),
+            patch("web_view.search_no_link", return_value=(1, hits)),
+        ):
+            response = self.client.get("/link/DVD_documentary")
+
+        body = response.get_data(as_text=True)
+        self.assertEqual(response.status_code, 200)
+        self.assertIn("No more candidates found for this article.", body)
+
+
+class ValidHitTests(unittest.TestCase):
+    def setUp(self) -> None:
+        web_view.app.config["TESTING"] = True
+        self.client = web_view.app.test_client()
+
+    def test_redirect_target_is_not_valid_hit(self) -> None:
+        with patch("web_view.get_diff") as get_diff:
+            response = self.client.get(
+                "/api/1/valid_hit",
+                query_string={
+                    "link_to": "DVD documentary",
+                    "link_from": "Documentary film",
+                    "redirect_to": "Documentary film",
+                },
+            )
+
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.get_json(), {"valid": False})
+        get_diff.assert_not_called()
+
 
 class ProtectedCandidateTests(unittest.TestCase):
     def test_edit_protected_hits_are_filtered_out(self) -> None: