fix: bootstrapped client can do evaluation when not ready

This commit will allow variation calls to use bootstrapped values during the client initialization process.

Author: joker23

packages/sdk/browser/src/BrowserClient.ts

@@ -18,6 +18,7 @@ import {
   Platform,
 } from '@launchdarkly/js-client-sdk-common';
 
+import { readFlagsFromBootstrap } from './bootstrap';
 import { getHref } from './BrowserApi';
 import BrowserDataManager from './BrowserDataManager';
 import { BrowserIdentifyOptions as LDIdentifyOptions } from './BrowserIdentifyOptions';
@@ -32,6 +33,7 @@ import BrowserPlatform from './platform/BrowserPlatform';
 class BrowserClientImpl extends LDClientImpl {
   private readonly _goalManager?: GoalManager;
   private readonly _plugins?: LDPlugin[];
+  private _bootstrapAttempted = false;
 
   constructor(
     clientSideId: string,
@@ -197,6 +199,12 @@ class BrowserClientImpl extends LDClientImpl {
     );
   }
 
+  /**
+   * @ignore
+   * NOTE: this identify is not doing anything as the `makeClient` function maps the
+   * identify function to identifyResults. We will need to consolidate this function
+   * in the js-client-sdk-common package.
+   */
   override async identify(context: LDContext, identifyOptions?: LDIdentifyOptions): Promise<void> {
     return super.identify(context, identifyOptions);
   }
@@ -211,6 +219,21 @@ class BrowserClientImpl extends LDClientImpl {
     if (identifyOptions?.sheddable === undefined) {
       identifyOptionsWithUpdatedDefaults.sheddable = true;
     }
+
+    if (!this._bootstrapAttempted && identifyOptionsWithUpdatedDefaults.bootstrap) {
+      try {
+        const bootstrapData = readFlagsFromBootstrap(
+          this.logger,
+          identifyOptionsWithUpdatedDefaults.bootstrap,
+        );
+        this.setBootstrap(context, bootstrapData);
+      } catch (e) {
+        this.logger.error('failed to bootstrap data');
+      } finally {
+        this._bootstrapAttempted = true;
+      }
+    }
+
     const res = await super.identifyResult(context, identifyOptionsWithUpdatedDefaults);
     this._goalManager?.startTracking();
     return res;

packages/shared/sdk-client/src/LDClientImpl.ts

@@ -43,6 +43,7 @@ import createEventProcessor from './events/createEventProcessor';
 import EventFactory from './events/EventFactory';
 import DefaultFlagManager, { FlagManager } from './flag-manager/FlagManager';
 import { FlagChangeType } from './flag-manager/FlagUpdater';
+import { ItemDescriptor } from './flag-manager/ItemDescriptor';
 import HookRunner from './HookRunner';
 import { getInspectorHook } from './inspection/getInspectorHook';
 import InspectorManager from './inspection/InspectorManager';
@@ -360,6 +361,19 @@ export default class LDClientImpl implements LDClient, LDClientIdentifyResult {
     return Promise.race([callSitePromise, timeoutPromise]);
   }
 
+  /**
+   * Exposes the bootstrap functionality to the derived classes. This function is mainly used to help set
+   * flag values for bootstrapped clients before the initialization is complete.
+   *
+   * @param pristineContext The LDContext object to be identified.
+   * @param newFlags The new flags to set.
+   */
+  protected setBootstrap(pristineContext: LDContext, newFlags: { [key: string]: ItemDescriptor }) {
+    this._uncheckedContext = pristineContext;
+    this._checkedContext = Context.fromLDContext(this._uncheckedContext);
+    this._flagManager.setBootstrap(this._checkedContext, newFlags);
+  }
+
   on(eventName: EventName, listener: Function): void {
     this.emitter.on(eventName, listener);
   }