From 0740530651f786a5530632b212209d435d2cbff7 Mon Sep 17 00:00:00 2001
From: Matthew Evans <git@ml-evs.science>
Date: Mon, 18 Jan 2021 14:25:55 +0000
Subject: [PATCH] Add fallback values for enum fields to use on validation

---
 optimade/validator/config.py    | 15 ++++++++++--
 optimade/validator/validator.py | 43 +++++++++++++++------------------
 2 files changed, 32 insertions(+), 26 deletions(-)

diff --git a/optimade/validator/config.py b/optimade/validator/config.py
index d9de66fd40..de626cfa0c 100644
--- a/optimade/validator/config.py
+++ b/optimade/validator/config.py
@@ -7,10 +7,10 @@
 
 """
 
-from typing import Dict, Any, Set
+from typing import Dict, Any, Set, List
 from pydantic import BaseSettings, Field
 
-from optimade.models import InfoResponse, IndexInfoResponse, DataType
+from optimade.models import InfoResponse, IndexInfoResponse, DataType, StructureFeatures
 from optimade.validator.utils import (
     ValidatorLinksResponse,
     ValidatorReferenceResponseOne,
@@ -50,6 +50,12 @@
     "links": ValidatorLinksResponse,
 }
 
+_ENUM_DUMMY_VALUES = {
+    "structures": {
+        "structure_features": [allowed.value for allowed in StructureFeatures]
+    }
+}
+
 
 _UNIQUE_PROPERTIES = ("id", "immutable_id")
 
@@ -159,5 +165,10 @@ class ValidatorConfig(BaseSettings):
         description="Field names to treat as top-level",
     )
 
+    enum_fallback_values: Dict[str, Dict[str, List[str]]] = Field(
+        _ENUM_DUMMY_VALUES,
+        description="Provide fallback values for enum fields to use when validating filters.",
+    )
+
 
 VALIDATOR_CONFIG = ValidatorConfig()
diff --git a/optimade/validator/validator.py b/optimade/validator/validator.py
index 432dc023b0..6e770c2201 100644
--- a/optimade/validator/validator.py
+++ b/optimade/validator/validator.py
@@ -685,7 +685,12 @@ def _construct_single_property_filters(
             # Otherwise, None values are not allowed for MUST's, and entire missing fields are not allowed
             raise ResponseError(msg)
 
+        using_fallback = False
         if prop_type == DataType.LIST:
+            if not test_value:
+                test_value = CONF.enum_fallback_values.get(endp).get(prop)
+                using_fallback = True
+
             if not test_value or (
                 isinstance(test_value[0], dict) or isinstance(test_value[0], list)
             ):
@@ -713,22 +718,17 @@ def _construct_single_property_filters(
                 request,
                 multistage=True,
                 optional=query_optional,
+                expected_status_code=(200, 501),
             )
 
             if not response:
                 if query_optional:
-                    return None, ""
+                    return (
+                        None,
+                        "Optional query {query!r} returned {reversed_response.status_code}.",
+                    )
                 raise ResponseError(
-                    f"Unable to perform {request}: failed with error {message}."
-                )
-
-            if response.status_code == 501:
-                self._log.warning(
-                    f"Implementation returned {response.content} for {query}"
-                )
-                return (
-                    True,
-                    "Implementation safely reported that filter {query} was not implemented.",
+                    f"Unable to perform mandatory query {query!r}: responded with status code {response.status_code}"
                 )
 
             response = response.json()
@@ -776,22 +776,17 @@ def _construct_single_property_filters(
                     reversed_request,
                     multistage=True,
                     optional=query_optional,
+                    expected_status_code=(200, 501),
                 )
 
                 if not reversed_response:
                     if query_optional:
-                        return None, ""
+                        return (
+                            None,
+                            "Optional query {query!r} returned {reversed_response.status_code}.",
+                        )
                     raise ResponseError(
-                        f"Unable to perform {reversed_request}: failed with error {message}."
-                    )
-
-                if reversed_response.status_code == 501:
-                    self._log.warning(
-                        f"Implementation returned {reversed_response.content} for {reversed_query}"
-                    )
-                    return (
-                        True,
-                        "Implementation safely reported that filter {reversed_query} was not implemented.",
+                        f"Unable to perform mandatory query {query!r}: responded with status code {reversed_response.status_code}"
                     )
 
                 reversed_response = reversed_response.json()
@@ -829,8 +824,8 @@ def _construct_single_property_filters(
                         f"Objects {excluded} were not necessarily excluded by {query}"
                     )
 
-            # check that at least the archetypal structure was returned
-            if not excluded:
+            # check that at least the archetypal structure was returned, unless we are using a fallback value
+            if not excluded and not using_fallback:
                 if (
                     num_data_returned[operator] is not None
                     and num_data_returned[operator] < 1