adjusting routing message serialization

Author: bigmontz

packages/bolt-connection/src/bolt/request-message.js

@@ -251,7 +251,16 @@ export default class RequestMessage {
    * @return {RequestMessage} the ROUTE message.
    */
    static routeV4x4 (routingContext = {}, bookmarks = [], databaseContext = {}) {
-    const dbContext = { db: databaseContext.databaseName, imp_user: databaseContext.impersonatedUser }
+    const dbContext = {}
+
+    if ( databaseContext.databaseName ) {
+      dbContext.db = databaseContext.databaseName
+    }
+    
+    if ( databaseContext.impersonatedUser ) {
+      dbContext.imp_user = databaseContext.impersonatedUser
+    }
+
     return new RequestMessage(
       ROUTE,
       [routingContext, bookmarks, dbContext],

packages/bolt-connection/test/bolt/request-message.test.js

@@ -291,7 +291,7 @@ describe('#unit RequestMessage', () => {
       expect(message.signature).toEqual(0x66)
       expect(message.fields).toEqual([{}, [], {}])
       expect(message.toString()).toEqual(
-        `ROUTE ${json.stringify({})} ${json.stringify([])} ${json.stringify({})}`
+        `ROUTE ${json.stringify({})} ${json.stringify([])} ${json.stringify({ })}`
       )
     })
 

packages/testkit-backend/src/request-handlers.js

@@ -265,7 +265,8 @@ export function GetFeatures (_context, _params, wire) {
       'Feature:Auth:Kerberos',
       'Feature:Auth:Bearer',
       'AuthorizationExpiredTreatment',
-      'ConfHint:connection.recv_timeout_seconds'
+      'ConfHint:connection.recv_timeout_seconds',
+      'Feature:Bolt:4.4'
     ]
   })
 }