Detailed msg when log filter not found (#428)

ethereum/jsonrpc/src/main/java/tech/pegasys/pantheon/ethereum/jsonrpc/internal/methods/EthGetFilterLogs.java

@@ -48,6 +48,6 @@ public class EthGetFilterLogs implements JsonRpcMethod {
       return new JsonRpcSuccessResponse(request.getId(), new LogsResult(logs));
     }
 
-    return new JsonRpcErrorResponse(request.getId(), JsonRpcError.FILTER_NOT_FOUND);
+    return new JsonRpcErrorResponse(request.getId(), JsonRpcError.LOGS_FILTER_NOT_FOUND);
   }
 }

ethereum/jsonrpc/src/main/java/tech/pegasys/pantheon/ethereum/jsonrpc/internal/response/JsonRpcError.java

@@ -28,6 +28,7 @@ public enum JsonRpcError {
 
   // Filter & Subscription Errors
   FILTER_NOT_FOUND(-32000, "Filter not found"),
+  LOGS_FILTER_NOT_FOUND(-32000, "Logs filter not found"),
   SUBSCRIPTION_NOT_FOUND(-32000, "Subscription not found"),
   NO_MINING_WORK_FOUND(-32000, "No mining work available yet"),
 

ethereum/jsonrpc/src/test/java/tech/pegasys/pantheon/ethereum/jsonrpc/internal/methods/EthGetFilterLogsTest.java

@@ -88,7 +88,7 @@ public class EthGetFilterLogsTest {
   public void shouldReturnFilterNotFoundWhenFilterManagerReturnsNull() {
     final JsonRpcRequest request = requestWithFilterId("NOT FOUND");
     final JsonRpcResponse expectedResponse =
-        new JsonRpcErrorResponse(null, JsonRpcError.FILTER_NOT_FOUND);
+        new JsonRpcErrorResponse(null, JsonRpcError.LOGS_FILTER_NOT_FOUND);
     when(filterManager.logs(eq("NOT FOUND"))).thenReturn(null);
 
     final JsonRpcResponse response = method.response(request);