Expand operator hard-negative AOIs

backend/tests/test_sprint131_operator_sample_expansion.py

@@ -25,7 +25,16 @@ def test_operator_sample_registry_includes_kempen_reference_and_background_candi
     module = load_sample_preparer()
 
     expected_reference_slugs = {"geel", "mol", "turnhout", "herentals", "balen", "retie", "westerlo"}
-    expected_background_slugs = {"postel_bos", "lommel_heide", "kasterlee_bos"}
+    expected_background_slugs = {
+        "postel_bos",
+        "lommel_heide",
+        "kasterlee_bos",
+        "dessel_heide",
+        "ravels_bos",
+        "meerhout_bos",
+        "geel_bel",
+        "arendonk_heide",
+    }
 
     assert expected_reference_slugs.issubset(module.SAMPLES)
     assert expected_background_slugs.issubset(module.SAMPLES)
@@ -34,6 +43,26 @@ def test_operator_sample_registry_includes_kempen_reference_and_background_candi
     assert all(module.SAMPLES[slug].sample_role == "background_candidate" for slug in expected_background_slugs)
 
 
+def test_operator_background_candidates_are_unique_enough_for_hard_negative_training() -> None:
+    module = load_sample_preparer()
+
+    background_samples = [
+        sample
+        for sample in module.SAMPLES.values()
+        if sample.sample_role == "background_candidate"
+    ]
+    centers = {(round(sample.center_lon, 4), round(sample.center_lat, 4)) for sample in background_samples}
+    half_sizes = {sample.half_size_m for sample in background_samples}
+
+    assert len(background_samples) >= 8
+    assert len(centers) == len(background_samples)
+    assert min(sample.center_lon for sample in background_samples) < 4.85
+    assert max(sample.center_lon for sample in background_samples) > 5.25
+    assert min(sample.center_lat for sample in background_samples) < 51.18
+    assert max(sample.center_lat for sample in background_samples) > 51.33
+    assert half_sizes == {260.0}
+
+
 def test_background_candidate_can_write_empty_reference_geojson(tmp_path: Path, monkeypatch) -> None:
     module = load_sample_preparer()