I think it's done?

src/Objects/AccountStats.ts

@@ -1,15 +1,14 @@
-import {Ruleset} from "../rulesets";
+import {RulesetSchema} from "../rulesets";
 import {AccountStatsMongoData, OutcomeType, PlayerGameResults} from "./DefaultStatsMongoData";
 import {UpdateError} from "../errors";
 import StatsUpdater from "./StatsUpdater";
+import Ruleset from "./Ruleset";
 
 class AccountStats {
-    private data?: AccountStatsMongoData;
+    private data: AccountStatsMongoData;
     private readonly updater: StatsUpdater;
-    constructor(data?: AccountStatsMongoData) {
-        if (data) {
-            this.data = data;
-        }
+    constructor(data: AccountStatsMongoData) {
+        this.data = data;
         this.updater = new StatsUpdater();
     }
 
@@ -18,16 +17,22 @@ class AccountStats {
         this.updater.use(data);
     }
 
-    updateStats(playerGameResults: PlayerGameResults & {outcome: OutcomeType}, ruleset: Ruleset): void {
+    updateStats(playerGameResults: (PlayerGameResults & {outcome: OutcomeType})[], ruleset: Ruleset): void {
         if (this.data) {
-            this.updater.updateStats(playerGameResults, ruleset);
-            this.data.gamesPlayed += 1;
+            for (const playerGameResult of playerGameResults) {
+                this.updater.updateStats(playerGameResult, ruleset);
+                this.data.gamesPlayed += 1;
+            }
         }
         else {
             throw new UpdateError(`Cannot update without data! Call the use() method to hydrate the updater with data 
                 to analyse.`);
         }
     }
+
+    getData(): AccountStatsMongoData {
+        return this.data;
+    }
 }
 
 export default AccountStats;