Do not raise local OPTIMADE warnings at server level

optimade/server/middleware.py

@@ -22,6 +22,7 @@
 from optimade.server.routers.utils import BASE_URL_PREFIXES, get_base_url
 from optimade.warnings import (
     FieldValueNotRecognized,
+    LocalOptimadeWarning,
     OptimadeWarning,
     QueryParamNotUsed,
     TooManyValues,
@@ -361,6 +362,9 @@ def showwarning(
             warnings._showwarning_orig(message, category, filename, lineno, file, line)  # type: ignore[attr-defined]
             return
 
+        if isinstance(message, LocalOptimadeWarning):
+            return
+
         # Format warning
         try:
             title = str(message.title)

optimade/warnings.py

@@ -45,6 +45,12 @@ def __str__(self) -> str:
         return self.detail if self.detail is not None else ""
 
 
+class LocalOptimadeWarning(OptimadeWarning):
+    """A warning that is specific to a local implementation of the OPTIMADE API
+    and should not appear in the server log or response.
+    """
+
+
 class FieldValueNotRecognized(OptimadeWarning):
     """A field or value used in the request is not recognised by this implementation."""
 
@@ -57,7 +63,7 @@ class QueryParamNotUsed(OptimadeWarning):
     """A query parameter is not used in this request."""
 
 
-class MissingExpectedField(OptimadeWarning):
+class MissingExpectedField(LocalOptimadeWarning):
     """A field was provided with a null value when a related field was provided
     with a value."""