message: better error status code
diff: @@ -129,7 +129,7 @@ function validateRelatedTypes(types, fields) {
  if (field.relatedTypes) {
  for (let relatedTypeName of Object.keys(field.relatedTypes)) {
  if (!types.get(relatedTypeName)) {
  - throw new Error(`field "${fieldName}" refers to missing related type "${relatedTypeName}"`);
  + throw new Error(`field "${fieldName}" refers to missing related type "${relatedTypeName}"`, { status: 400 });
  }
  }
  }
  