Validate list LENGTH queries with validator (#1637)

* Validate LENGTH queries on lists

* Tweak validation of missing version: query versioned info instead

* Add optional LENGTH validation carve out for structure features

Author: ml-evs

optimade/validator/config.py

@@ -79,7 +79,7 @@
     ),
     DataType.INTEGER: inclusive_ops,
     DataType.FLOAT: (),
-    DataType.LIST: ("HAS", "HAS ALL", "HAS ANY"),
+    DataType.LIST: ("HAS", "HAS ALL", "HAS ANY", "LENGTH"),
 }
 
 exclusive_ops = ("!=", "<", ">")
@@ -108,6 +108,9 @@
             if op != "="
         ],
     },
+    "structure_features": {
+        SupportLevel.OPTIONAL: "LENGTH",
+    },
 }
 
 

optimade/validator/validator.py

@@ -682,6 +682,8 @@ def _format_test_value(test_value: Any, prop_type: DataType, operator: str) -> s
                 else:
                     _vals = [f"{val}" for val in _vals]
                 _test_value = ",".join(_vals)
+            elif operator == "LENGTH":
+                _test_value = f"{len(test_value)}"
             else:
                 if isinstance(test_value[0], str):
                     _test_value = f'"{test_value[0]}"'
@@ -1238,7 +1240,7 @@ def _test_bad_version_returns_553(self) -> None:
             expected_status_code = [404, 400]
 
         self._get_endpoint(
-            "v123123", expected_status_code=expected_status_code, optional=True
+            "v123123/info", expected_status_code=expected_status_code, optional=True
         )
 
     @test_case