Implement safeguard against problematic meta keys

ixmp4/data/db/meta/repository.py

@@ -7,6 +7,7 @@
 
 from ixmp4 import db
 from ixmp4.core.decorators import check_types
+from ixmp4.core.exceptions import InvalidRunMeta
 from ixmp4.data import abstract
 from ixmp4.data.auth.decorators import guard
 from ixmp4.data.db.model import Model
@@ -16,6 +17,8 @@
 from .. import base
 from .model import RunMetaEntry
 
+ILLEGAL_META_KEYS = {"model", "scenario", "id", "version", "is_default"}
+
 
 class RemoveRunMetaEntryFrameSchema(pa.DataFrameModel):
     key: Series[pa.String] = pa.Field(coerce=True)
@@ -60,6 +63,8 @@ def add(
                 default_only=False,
             )
 
+        if key in ILLEGAL_META_KEYS:
+            raise InvalidRunMeta("Illegal meta key: " + key)
         entry = RunMetaEntry(run__id=run__id, key=key, value=value)
         self.session.add(entry)
         return entry

tests/data/test_meta.py

@@ -2,7 +2,7 @@
 import pytest
 
 import ixmp4
-from ixmp4.core.exceptions import SchemaError
+from ixmp4.core.exceptions import InvalidRunMeta, SchemaError
 from ixmp4.data.abstract.meta import RunMetaEntry
 
 from ..utils import assert_unordered_equality
@@ -37,6 +37,11 @@ def test_create_get_entry(self, platform: ixmp4.Platform):
             assert entry.value == value
             assert entry.type == type
 
+    def test_illegal_key(self, platform: ixmp4.Platform):
+        run = platform.runs.create("Model", "Scenario")
+        with pytest.raises(InvalidRunMeta):
+            platform.backend.meta.create(run.id, "version", "foo")
+
     def test_entry_unique(self, platform: ixmp4.Platform):
         run = platform.runs.create("Model", "Scenario")
         platform.backend.meta.create(run.id, "Key", "Value")