test: cover malformed Gaussian parameters

tests/test_inspect_gaussian_ply.py

@@ -32,3 +32,32 @@ def test_gaussian_inspector_rejects_missing_evidence_field(tmp_path):
         assert "missing fields" in str(exc)
     else:
         raise AssertionError("missing Gaussian evidence fields should fail")
+
+
+def test_gaussian_inspector_rejects_invalid_rotation_and_confidence(tmp_path):
+    path = tmp_path / "bad_gaussians.ply"
+    write_gaussian_ply(
+        path,
+        np.array([[0, 0, 1]], dtype=np.float32),
+        np.array([[255, 0, 0]], dtype=np.uint8),
+        np.array([1.5], dtype=np.float32),
+        np.array([0], dtype=np.int32),
+        np.array([1], dtype=np.int32),
+        rotations=np.array([[2, 0, 0, 0]], dtype=np.float32),
+        scales=np.ones((1, 3), dtype=np.float32),
+        opacities=np.array([0.5], dtype=np.float32),
+    )
+    lines = path.read_text(encoding="utf-8").splitlines()
+    end = lines.index("end_header")
+    properties = [line.split()[-1] for line in lines[:end] if line.startswith("property ")]
+    fields = lines[end + 1].split()
+    fields[properties.index("rot_0")] = "2"
+    fields[properties.index("confidence")] = "1.5"
+    lines[end + 1] = " ".join(fields)
+    path.write_text("\n".join(lines) + "\n", encoding="utf-8")
+    try:
+        inspect_gaussian_ply(path)
+    except ValueError as exc:
+        assert "normalized quaternions" in str(exc)
+    else:
+        raise AssertionError("invalid Gaussian quaternion should fail")