Add deterministic portfolio spec composition

tests/test_combine_belgium_building_portfolio_specs.py

@@ -0,0 +1,38 @@
+import json
+from pathlib import Path
+
+import pytest
+
+from scripts.combine_belgium_building_portfolio_specs import combine_specs
+
+
+def write_spec(path: Path, slug: str, *, resolution: float = 0.25, status: str = "complete") -> Path:
+    path.write_text(json.dumps({
+        "status": status,
+        "side_m": 256.0,
+        "resolution_m": resolution,
+        "samples": [{"sample_slug": slug}],
+    }), encoding="utf-8")
+    return path
+
+
+def test_combine_specs_records_provenance(tmp_path: Path) -> None:
+    payload = combine_specs([write_spec(tmp_path / "one.json", "one"), write_spec(tmp_path / "two.json", "two")])
+    assert payload["sample_count"] == 2
+    assert [sample["sample_slug"] for sample in payload["samples"]] == ["one", "two"]
+    assert all(len(source["sha256"]) == 64 for source in payload["source_specs"])
+
+
+def test_combine_specs_rejects_duplicate_slugs(tmp_path: Path) -> None:
+    with pytest.raises(ValueError, match="Duplicate"):
+        combine_specs([write_spec(tmp_path / "one.json", "same"), write_spec(tmp_path / "two.json", "same")])
+
+
+def test_combine_specs_rejects_mismatched_resolution(tmp_path: Path) -> None:
+    with pytest.raises(ValueError, match="resolution"):
+        combine_specs([write_spec(tmp_path / "one.json", "one"), write_spec(tmp_path / "two.json", "two", resolution=0.5)])
+
+
+def test_combine_specs_rejects_incomplete_source(tmp_path: Path) -> None:
+    with pytest.raises(ValueError, match="not complete"):
+        combine_specs([write_spec(tmp_path / "one.json", "one", status="in_progress")])