check invalid merge

tests/data/model_merge_invalid.md

@@ -0,0 +1,20 @@
+---
+id-field: true
+repo: "https://www.github.com/my/repo/"
+prefix: "tst"
+prefixes:
+  schema: http://schema.org/
+nsmap:
+  tst: http://example.com/test/
+---
+
+### Test
+
+- __other__
+  - Type: string
+
+### Ontology
+
+```
+OTHER = "Something other"
+```

tests/integration_tests.rs

@@ -246,4 +246,17 @@ mod tests {
         assert!(enum_names.contains(&"Ontology".to_string()));
         assert!(enum_names.contains(&"AddedEnum".to_string()));
     }
+
+    #[test]
+    #[should_panic]
+    fn test_model_merge_invalid() {
+        // Arrange
+        let path = Path::new("tests/data/model.md");
+        let mut model = DataModel::from_markdown(path).expect("Could not parse markdown");
+        let path2 = Path::new("tests/data/model_merge_invalid.md");
+        let model2 = DataModel::from_markdown(path2).expect("Could not parse markdown");
+
+        // Act
+        model.merge(&model2);
+    }
 }