I think it's done?

src/ObjectCollections/RulesetCollection.ts

@@ -0,0 +1,30 @@
+import MongoStoredObjectCollection from "./MongoStoredObjectCollection";
+import mongo from "mongodb";
+import {DEFAULT_RULESET, DEFAULT_RULESET_NAME, RulesetSchema} from "../rulesets";
+import {getMongoObjectCollection} from "../database";
+import Ruleset from "../Objects/Ruleset";
+
+type RulesetMongoData = RulesetSchema;
+
+class RulesetCollection extends MongoStoredObjectCollection<RulesetMongoData> {
+    constructor(collectionClient: mongo.Collection) {
+        super(collectionClient);
+    }
+
+    private async rulesetFrom(data: RulesetMongoData): Promise<Ruleset> {
+        return new Ruleset(data.id, data);
+    }
+
+    async read(id: string): Promise<Ruleset> {
+        if (id === DEFAULT_RULESET_NAME) {
+            return new Ruleset(DEFAULT_RULESET_NAME, DEFAULT_RULESET);
+        }
+        else {
+            const foundRuleset = await this.mongoRead(id);
+            return this.rulesetFrom(foundRuleset);
+        }
+    }
+}
+
+const RulesetCollectionSingleton = new RulesetCollection(getMongoObjectCollection("users"));
+export default RulesetCollectionSingleton;