add memory-only bandit configuration store for offline client. (#150)

* add memory-only bandit configuration store for offline client.

* salt

Author: leoromanovsky

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@eppo/js-client-sdk",
-  "version": "3.9.4-alpha.4",
+  "version": "3.9.4-alpha.5",
   "description": "Eppo SDK for client-side JavaScript applications",
   "main": "dist/index.js",
   "files": [

src/configuration-factory.ts

@@ -6,6 +6,7 @@ import {
   MemoryStore,
   PrecomputedFlag,
 } from '@eppo/js-client-sdk-common';
+import { IObfuscatedPrecomputedBandit } from '@eppo/js-client-sdk-common/dist/interfaces';
 
 import ChromeStorageAsyncMap from './cache/chrome-storage-async-map';
 import { ChromeStorageEngine } from './chrome-storage-engine';
@@ -20,6 +21,10 @@ export function precomputedFlagsStorageFactory(): IConfigurationStore<Precompute
   return new MemoryOnlyConfigurationStore();
 }
 
+export function precomputedBanditStoreFactory(): IConfigurationStore<IObfuscatedPrecomputedBandit> {
+  return new MemoryOnlyConfigurationStore();
+}
+
 export function configurationStorageFactory(
   {
     maxAgeSeconds = 0,

src/index.ts

@@ -33,6 +33,7 @@ import {
   hasChromeStorage,
   hasWindowLocalStorage,
   localStorageIfAvailable,
+  precomputedBanditStoreFactory,
 } from './configuration-factory';
 import BrowserNetworkStatusListener from './events/browser-network-status-listener';
 import LocalStorageBackedNamedEventQueue from './events/local-storage-backed-named-event-queue';
@@ -721,6 +722,14 @@ export function offlinePrecomputedInit(
       );
     memoryOnlyPrecomputedStore.salt = parsedResponse.salt;
 
+    const memoryOnlyPrecomputedBanditStore = precomputedBanditStoreFactory();
+    memoryOnlyPrecomputedBanditStore
+      .setEntries(parsedResponse.bandits)
+      .catch((err) =>
+        applicationLogger.warn('Error setting precomputed bandits for memory-only store', err),
+      );
+    memoryOnlyPrecomputedBanditStore.salt = parsedResponse.salt;
+
     const subject: Subject = {
       subjectKey,
       subjectAttributes: subjectAttributes ?? {},
@@ -729,6 +738,7 @@ export function offlinePrecomputedInit(
     shutdownEppoPrecomputedClient();
     EppoPrecomputedJSClient.instance = new EppoPrecomputedJSClient({
       precomputedFlagStore: memoryOnlyPrecomputedStore,
+      precomputedBanditStore: memoryOnlyPrecomputedBanditStore,
       subject,
     });