Revert client instantiate inside of init method. Create with empty … (#68)

Revert client instantiate inside of `init` method. Create with empty in-memory store. Populate the configuration store in `init`.

Author: leoromanovsky

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@eppo/js-client-sdk",
-  "version": "3.0.2-rc.0",
+  "version": "3.0.2-rc.1",
   "description": "Eppo SDK for client-side JavaScript applications",
   "main": "dist/index.js",
   "files": [
@@ -57,7 +57,7 @@
     "webpack-cli": "^4.10.0"
   },
   "dependencies": {
-    "@eppo/js-client-sdk-common": "3.0.6",
+    "@eppo/js-client-sdk-common": "3.0.8",
     "md5": "^2.3.0"
   }
-}
+}

src/configuration-factory.ts

@@ -11,8 +11,11 @@ import { LocalStorageBackedAsyncStore } from './local-storage';
 
 export function configurationStorageFactory(
   persistenceStore?: IAsyncStore<Flag>,
+  forceMemoryOnly = false,
 ): IConfigurationStore<Flag> {
-  if (persistenceStore) {
+  if (forceMemoryOnly) {
+    return new MemoryOnlyConfigurationStore();
+  } else if (persistenceStore) {
     return new HybridConfigurationStore(new MemoryStore<Flag>(), persistenceStore);
   } else if (hasWindowLocalStorage()) {
     // fallback to window.localStorage if available

src/index.ts

@@ -82,12 +82,18 @@ export interface IClientConfig {
 
 export { IAssignmentLogger, IAssignmentEvent, IEppoClient } from '@eppo/js-client-sdk-common';
 
+// Instantiate the configuration store with memory-only implementation.
+const configurationStore = configurationStorageFactory(undefined, true);
+
 /**
  * Client for assigning experiment variations.
  * @public
  */
 export class EppoJSClient extends EppoClient {
-  public static instance: EppoJSClient;
+  // Ensure that the client is instantiated during class loading.
+  // Use an empty memory-only configuration store until the `init` method is called,
+  // to avoid serving stale data to the user.
+  public static instance: EppoJSClient = new EppoJSClient(configurationStore, undefined, true);
   public static initialized = false;
 
   public getStringAssignment(
@@ -161,8 +167,10 @@ export async function init(config: IClientConfig): Promise<IEppoClient> {
       EppoJSClient.instance.stopPolling();
     }
 
-    const configurationStore = configurationStorageFactory(config.persistentStore);
-    EppoJSClient.instance = new EppoJSClient(configurationStore, undefined, true);
+    // Set the configuration store to the desired persistent store, if provided.
+    // Otherwise the factory method will detect the current environment and instantiate the correct store.
+    const configurationStore = configurationStorageFactory(config.persistentStore, false);
+    EppoJSClient.instance.setConfigurationStore(configurationStore);
 
     const requestConfiguration: FlagConfigurationRequestParameters = {
       apiKey: config.apiKey,

yarn.lock

@@ -380,10 +380,10 @@
   resolved "https://registry.yarnpkg.com/@discoveryjs/json-ext/-/json-ext-0.5.7.tgz#1d572bfbbe14b7704e0ba0f39b74815b84870d70"
   integrity sha512-dBVuXR082gk3jsFp7Rd/JI4kytwGHecnCoTtXFb7DB6CNHp4rg5k1bhg0nWdLGLnOV71lmDzGQaLMy8iPLY0pw==
 
-"@eppo/[email protected].6":
-  version "3.0.6"
-  resolved "https://registry.yarnpkg.com/@eppo/js-client-sdk-common/-/js-client-sdk-common-3.0.6.tgz#8d2019d45708b944e26e493f09bcce833925ffa1"
-  integrity sha512-YV32rf2UjNuKDAwyEl2HKearxsHRr2UDOJl+xblq5RCG8KB19xjxlNoUeFHd6FwTmqDVFF998r2DDEzoL496YQ==
+"@eppo/[email protected].8":
+  version "3.0.8"
+  resolved "https://registry.yarnpkg.com/@eppo/js-client-sdk-common/-/js-client-sdk-common-3.0.8.tgz#738c67c2ae95d4c8b8b84cd8625ff010e11ac6cc"
+  integrity sha512-Qe7O78Pt2PYyTXMLYQMoGyv0aOu5NdXsO1VWBCjA6aUqkWKyy4etyMy1BXpwsbxH6kvKq1uwTJO19N7zoCVFlQ==
   dependencies:
     md5 "^2.3.0"
     pino "^8.19.0"