Harden operator tile background metadata

backend/tests/test_sprint130_operator_yolo_tile_dataset.py

@@ -147,3 +147,27 @@ def test_background_negative_repeat_only_applies_to_training_background_tiles()
         split="train",
         background_negative_repeat=4,
     ) == 1
+
+
+def test_background_category_is_derived_for_legacy_operator_manifests() -> None:
+    module = load_tile_exporter()
+
+    pure_empty_sample = {
+        "sample_slug": "postel_bos",
+        "sample_role": "background_candidate",
+        "reference_feature_count": 0,
+    }
+    sparse_context_sample = {
+        "sample_slug": "kasterlee_bos",
+        "sample_role": "background_candidate",
+        "reference_feature_count": 104,
+    }
+    reference_sample = {
+        "sample_slug": "geel",
+        "sample_role": "reference",
+        "reference_feature_count": 2500,
+    }
+
+    assert module.background_category_for_sample(pure_empty_sample) == "pure_empty_negative"
+    assert module.background_category_for_sample(sparse_context_sample) == "sparse_building_context"
+    assert module.background_category_for_sample(reference_sample) == "reference_aoi"

backend/tests/test_sprint156_background_corpus_classification.py

@@ -20,6 +20,17 @@ def load_sample_preparer():
     return module
 
 
+def load_tile_exporter():
+    script_path = ROOT / "scripts" / "export_operator_yolo_tile_dataset.py"
+    spec = importlib.util.spec_from_file_location("operator_tile_exporter_s156", script_path)
+    assert spec is not None
+    assert spec.loader is not None
+    module = importlib.util.module_from_spec(spec)
+    sys.modules[spec.name] = module
+    spec.loader.exec_module(module)
+    return module
+
+
 def test_background_samples_are_classified_by_actual_reference_density() -> None:
     module = load_sample_preparer()
 
@@ -93,7 +104,21 @@ def test_hard_negative_matrix_can_filter_background_categories() -> None:
 
 
 def test_yolo_tile_export_preserves_background_category_provenance() -> None:
+    module = load_tile_exporter()
     script = (ROOT / "scripts" / "export_operator_yolo_tile_dataset.py").read_text(encoding="utf-8")
 
-    assert "background_category = str(sample.get(\"background_category\") or \"reference_aoi\")" in script
+    assert module.background_category_for_sample(
+        {
+            "sample_slug": "postel_bos",
+            "sample_role": "background_candidate",
+            "reference_feature_count": 0,
+        }
+    ) == "pure_empty_negative"
+    assert module.background_category_for_sample(
+        {
+            "sample_slug": "kasterlee_bos",
+            "sample_role": "background_candidate",
+            "reference_feature_count": 104,
+        }
+    ) == "sparse_building_context"
     assert "\"background_category\": background_category" in script