Test safe model-introduction stripping and runtime caption prompt

tests/test_caption_text.py

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+from __future__ import annotations
+
+import unittest
+from unittest.mock import Mock
+
+from scene_search.caption_text import remove_image_preface
+from scene_search.captioner import OllamaCaptioner
+
+
+class CaptionTextTests(unittest.TestCase):
+    def test_removes_model_image_set_introductions(self) -> None:
+        examples = {
+            "The video features a series of still images showing a man wearing a red coat.":
+                "A man wearing a red coat.",
+            "A series of images depicts a woman standing beside a blue car.":
+                "A woman standing beside a blue car.",
+            "These frames show two people walking along a beach.":
+                "Two people walking along a beach.",
+            "This clip contains a collection of photographs depicting an old bridge at night.":
+                "An old bridge at night.",
+            "The images depict a small dog lying on the sofa.":
+                "A small dog lying on the sofa.",
+        }
+        for original, expected in examples.items():
+            with self.subTest(original=original):
+                self.assertEqual(remove_image_preface(original), expected)
+
+    def test_only_anchored_presentation_boilerplate_is_removed(self) -> None:
+        examples = [
+            "A photographer is sorting a series of photos on a desk.",
+            "The video features a series of still images showing a",
+            "A row of framed pictures hangs behind a woman.",
+            "A person displays a sequence of images on a monitor.",
+            "A woman walks through a building and waves to the camera.",
+        ]
+        for original in examples:
+            with self.subTest(original=original):
+                self.assertEqual(remove_image_preface(original), original)
+
+    def test_live_caption_generation_normalises_response_and_changes_prompt(self) -> None:
+        captioner = OllamaCaptioner("http://ollama.test", "vision-test")
+        response = Mock()
+        response.ok = True
+        response.json.return_value = {
+            "message": {
+                "content": (
+                    "The video features a series of still images showing a "
+                    "person walking across a street."
+                )
+            }
+        }
+        captioner.session.post = Mock(return_value=response)
+        result = captioner._caption_b64("an-image", chronological_sequence=True)
+        self.assertEqual(result, "A person walking across a street.")
+        prompt = captioner.session.post.call_args.kwargs["json"]["messages"][0]["content"]
+        self.assertIn("Never introduce your answer", prompt)
+        self.assertIn("Do not invent motion", prompt)
+
+
+if __name__ == "__main__":
+    unittest.main()