Fix result wrapping

Signed-off-by: Pavol Loffay <p.loffay@gmail.com>

cmd/query/app/otel/grpc_gateway_test.go

@@ -16,6 +16,7 @@ package otel
 
 import (
 	"bytes"
+	"encoding/json"
 	"fmt"
 	"net"
 	"net/http"
@@ -79,16 +80,18 @@ func TestGRPCGateway(t *testing.T) {
 	_, err = buf.ReadFrom(response.Body)
 	require.NoError(t, err)
 
-	// The streaming API wraps response objects into '{"result": ...}'
-	// This has to be removed if we want to parse it into SpansResponseChunk
-	str := buf.Bytes()[14:]
-	str = str[:len(str)-2]
-
-	var spansResponse api_v3.SpansResponseChunk
 	jsonpb := &JSONPb{}
-	err = jsonpb.Unmarshal(str, &spansResponse)
+	var w resultWrapper
+	err = json.Unmarshal(buf.Bytes(), &w)
+	require.NoError(t, err)
+	var spansResponse api_v3.SpansResponseChunk
+	err = jsonpb.Unmarshal(w.Result, spansResponse)
 	require.NoError(t, err)
 	assert.Equal(t, 1, len(spansResponse.GetResourceSpans()))
 	assert.Equal(t, uint64ToTraceID(traceID.High, traceID.Low), spansResponse.GetResourceSpans()[0].GetInstrumentationLibrarySpans()[0].GetSpans()[0].TraceId.Bytes())
-	fmt.Println(response)
+}
+
+// see https://github.com/grpc-ecosystem/grpc-gateway/issues/2189
+type resultWrapper struct {
+	Result json.RawMessage `json:"result"`
 }

proto-gen/api_v3/query_service.swagger.json

@@ -321,7 +321,7 @@
           "title": "OTLP resource spans\nsee https://github.com/open-telemetry/opentelemetry-proto/blob/main/opentelemetry/proto/trace/v1/trace.proto"
         }
       },
-      "description": "A single response chunk holds a single trace."
+      "description": "A single response chunk holds a single trace.\nNote that a subsequent request to get a trace might return a different result\nbecause spans are reported in asynchronous chunks."
     },
     "api_v3TraceQueryParameters": {
       "type": "object",