Fix usage of filters in /query endpoint in REST API (#1774)

* WIP filter refactoring

* fix filter formatting

* remove inplace modification of filters

haystack/document_stores/elasticsearch.py

@@ -737,7 +737,7 @@ class ElasticsearchDocumentStore(BaseDocumentStore):
                 filter_clause = []
                 for key, values in filters.items():
                     if type(values) != list:
-                        raise ValueError(f'Wrong filter format for key "{key}": Please provide a list of allowed values for each key. '
+                        raise ValueError(f'Wrong filter format: "{key}": {values}. Provide a list of values for each key. '
                                          'Example: {"name": ["some", "more"], "category": ["only_one"]} ')
                     filter_clause.append(
                         {

rest_api/application.py

@@ -50,7 +50,7 @@ use_route_names_as_operation_ids(app)
 logger.info("Open http://127.0.0.1:8000/docs to see Swagger API Documentation.")
 logger.info(
     """
-    Or just try it out directly: curl --request POST --url 'http://127.0.0.1:8000/query' -H "Content-Type: application/json"  --data '{"query": "Did Albus Dumbledore die?"}'
+    Or just try it out directly: curl --request POST --url 'http://127.0.0.1:8000/query' -H "Content-Type: application/json"  --data '{"query": "Who is the father of Arya Stark?"}'
     """
 )
 

rest_api/controller/search.py

@@ -53,19 +53,38 @@ def _process_request(pipeline, request) -> QueryResponse:
     start_time = time.time()
     
     params = request.params or {}
-    params["Retriever"] = params.get("Retriever", {})
-    filters = {}
-    if "filters" in params["Retriever"]:  # put filter values into a list and remove filters with null value
-        for key, values in params["Retriever"]["filters"].items():
-            if values is None:
-                continue
-            if not isinstance(values, list):
-                values = [values]
-            filters[key] = values
-    params["Retriever"]["filters"] = filters
-    result = pipeline.run(query=request.query, params=params)
-    
+
+    # format global, top-level filters (e.g. "params": {"filters": {"name": ["some"]}})
+    if "filters" in params.keys():
+        params["filters"] = _format_filters(params["filters"])
+
+    # format targeted node filters (e.g. "params": {"Retriever": {"filters": {"value"}}})
+    for key, value in params.items():
+        if "filters" in params[key].keys():
+            params[key]["filters"] = _format_filters(params[key]["filters"])
+
+    result = pipeline.run(query=request.query, params=params,debug=request.debug)
     end_time = time.time()
     logger.info({"request": request.dict(), "response": result, "time": f"{(end_time - start_time):.2f}"})
 
     return result
+
+
+def _format_filters(filters):
+    """
+    Adjust filters to compliant format:
+    Put filter values into a list and remove filters with null value.
+    """
+    new_filters = {}
+    for key, values in filters.items():
+        if values is None:
+            logger.warning(f"Request with deprecated filter format ('{key}: null'). "
+                           f"Remove null values from filters to be compliant with future versions")
+            continue
+        elif not isinstance(values, list):
+            logger.warning(f"Request with deprecated filter format ('{key}': {values}). "
+                           f"Change to '{key}':[{values}]' to be compliant with future versions")
+            values = [values]
+
+        new_filters[key] = values
+    return new_filters

rest_api/schema.py

@@ -1,5 +1,5 @@
 from typing import Dict, List, Optional, Union, Any
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, Field, Extra
 from haystack.schema import Answer, Document, Label, Span
 from pydantic import BaseConfig
 from pydantic.dataclasses import dataclass as pydantic_dataclass
@@ -11,11 +11,13 @@ except ImportError:
 
 BaseConfig.arbitrary_types_allowed = True
 
-
 class QueryRequest(BaseModel):
     query: str
     params: Optional[dict] = None
-
+    debug: Optional[bool] = False
+    class Config:
+        # Forbid any extra fields in the request to avoid silent failures
+        extra = Extra.forbid
 
 class FilterRequest(BaseModel):
     filters: Optional[Dict[str, Optional[Union[str, List[str]]]]] = None
@@ -41,4 +43,5 @@ class QueryResponse(BaseModel):
     query: str
     answers: List[AnswerSerialized]
     documents: Optional[List[DocumentSerialized]]
+    debug: Optional[Dict] = Field(None, alias="_debug")
 

test/test_rest_api.py

@@ -157,6 +157,14 @@ def test_query_with_one_filter(populated_client: TestClient):
     assert response_json["answers"][0]["answer"] == "Adobe Systems"
 
 
+def test_query_with_one_global_filter(populated_client: TestClient):
+    query_with_filter = {"query": "Who made the PDF specification?", "params": {"filters": {"meta_key": "meta_value"}}}
+    response = populated_client.post(url="/query", json=query_with_filter)
+    assert 200 == response.status_code
+    response_json = response.json()
+    assert response_json["answers"][0]["answer"] == "Adobe Systems"
+
+
 def test_query_with_filter_list(populated_client: TestClient):
     query_with_filter_list = {
         "query": "Who made the PDF specification?",