feat: make heatmap layers extensible via LayerRegistry (OCP)

backend/tests/test_heatmap_layer_registry.py

@@ -0,0 +1,58 @@
+"""Tests for the heatmap layer registry (OCP extensibility)."""
+
+import pytest
+
+from app.services.heatmap_service import (
+    LAYER_REGISTRY,
+    SUPPORTED_LAYER_TYPES,
+    register_layer,
+)
+
+
+def test_builtin_layer_types_registered():
+    assert "coverage" in SUPPORTED_LAYER_TYPES
+    assert "detection-rules" in SUPPORTED_LAYER_TYPES
+    assert "threat-actor" in SUPPORTED_LAYER_TYPES
+    assert "campaign" in SUPPORTED_LAYER_TYPES
+
+
+def test_register_custom_simple_layer():
+    def my_layer(db, *, platforms=None, tactics=None, min_score=0):
+        return {"name": "custom", "techniques": []}
+
+    register_layer("custom-test-layer", my_layer)
+    assert "custom-test-layer" in LAYER_REGISTRY.supported_types
+
+    result = LAYER_REGISTRY.build(
+        None, "custom-test-layer",
+        platforms=None, tactics=None, min_score=0,
+    )
+    assert result["name"] == "custom"
+
+
+def test_register_custom_id_layer():
+    def my_id_layer(db, layer_id, *, platforms=None, tactics=None, min_score=0):
+        return {"name": f"entity-{layer_id}", "techniques": []}
+
+    register_layer("custom-id-layer", my_id_layer, requires_id=True)
+    assert "custom-id-layer" in LAYER_REGISTRY.supported_types
+
+    result = LAYER_REGISTRY.build(
+        None, "custom-id-layer",
+        layer_id="abc-123", platforms=None, tactics=None, min_score=0,
+    )
+    assert result["name"] == "entity-abc-123"
+
+
+def test_unknown_layer_raises():
+    from app.domain.errors import BusinessRuleViolation
+
+    with pytest.raises(BusinessRuleViolation, match="Unknown layer type"):
+        LAYER_REGISTRY.build(None, "nonexistent-layer")
+
+
+def test_id_layer_without_id_raises():
+    from app.domain.errors import BusinessRuleViolation
+
+    with pytest.raises(BusinessRuleViolation, match="layer_id is required"):
+        LAYER_REGISTRY.build(None, "threat-actor", layer_id=None)