From 8ad3d819e332c0b3e3ae47fc7e373038ebd9a51b Mon Sep 17 00:00:00 2001
From: Tim Yiu <137842098+tyiuhc@users.noreply.github.com>
Date: Tue, 7 Oct 2025 13:58:06 -0700
Subject: [PATCH 01/14] fix: implement consent-aware default user provider

---
 packages/experiment-browser/src/factory.ts    |  6 +-
 packages/experiment-browser/src/index.ts      |  1 +
 .../src/providers/default.ts                  | 14 +++-
 packages/experiment-tag/src/experiment.ts     |  6 ++
 .../providers/consent-aware-user-provider.ts  | 68 +++++++++++++++++++
 .../experiment-tag/src/providers/types.ts     |  5 ++
 .../src/storage/consent-aware-storage.ts      | 37 ++++++++--
 7 files changed, 127 insertions(+), 10 deletions(-)
 create mode 100644 packages/experiment-tag/src/providers/consent-aware-user-provider.ts
 create mode 100644 packages/experiment-tag/src/providers/types.ts

diff --git a/packages/experiment-browser/src/factory.ts b/packages/experiment-browser/src/factory.ts
index 25f0aa6e..ac069b1f 100644
--- a/packages/experiment-browser/src/factory.ts
+++ b/packages/experiment-browser/src/factory.ts
@@ -71,7 +71,11 @@ const newExperimentClient = (
 ): ExperimentClient => {
   return new ExperimentClient(apiKey, {
     ...config,
-    userProvider: new DefaultUserProvider(config?.userProvider, apiKey),
+    userProvider:
+      // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+      // @ts-ignore
+      config.defaultUserProvider ??
+      new DefaultUserProvider(config?.userProvider, apiKey),
   });
 };
 
diff --git a/packages/experiment-browser/src/index.ts b/packages/experiment-browser/src/index.ts
index f19e72a8..7b54808d 100644
--- a/packages/experiment-browser/src/index.ts
+++ b/packages/experiment-browser/src/index.ts
@@ -34,3 +34,4 @@ export {
   ExperimentPluginType,
   ExperimentEvent,
 } from './types/plugin';
+export { DefaultUserProvider } from './providers/default';
diff --git a/packages/experiment-browser/src/providers/default.ts b/packages/experiment-browser/src/providers/default.ts
index ca4ae5e1..cbce1d2b 100644
--- a/packages/experiment-browser/src/providers/default.ts
+++ b/packages/experiment-browser/src/providers/default.ts
@@ -4,6 +4,7 @@ import { UAParser } from '@amplitude/ua-parser-js';
 import { LocalStorage } from '../storage/local-storage';
 import { SessionStorage } from '../storage/session-storage';
 import { ExperimentUserProvider } from '../types/provider';
+import { Storage } from '../types/storage';
 import { ExperimentUser } from '../types/user';
 
 export class DefaultUserProvider implements ExperimentUserProvider {
@@ -13,17 +14,24 @@ export class DefaultUserProvider implements ExperimentUserProvider {
       ? this.globalScope?.navigator.userAgent
       : undefined;
   private readonly ua = new UAParser(this.userAgent).getResult();
-  private readonly localStorage = new LocalStorage();
-  private readonly sessionStorage = new SessionStorage();
+  private readonly localStorage: Storage;
+  private readonly sessionStorage: Storage;
   private readonly storageKey: string;
 
   public readonly userProvider: ExperimentUserProvider | undefined;
   private readonly apiKey?: string;
 
-  constructor(userProvider?: ExperimentUserProvider, apiKey?: string) {
+  constructor(
+    userProvider?: ExperimentUserProvider,
+    apiKey?: string,
+    customLocalStorage?: Storage,
+    customSessionStorage?: Storage,
+  ) {
     this.userProvider = userProvider;
     this.apiKey = apiKey;
     this.storageKey = `EXP_${this.apiKey?.slice(0, 10)}_DEFAULT_USER_PROVIDER`;
+    this.localStorage = customLocalStorage || new LocalStorage();
+    this.sessionStorage = customSessionStorage || new SessionStorage();
   }
 
   getUser(): ExperimentUser {
diff --git a/packages/experiment-tag/src/experiment.ts b/packages/experiment-tag/src/experiment.ts
index 962031fc..a0671e22 100644
--- a/packages/experiment-tag/src/experiment.ts
+++ b/packages/experiment-tag/src/experiment.ts
@@ -17,6 +17,7 @@ import mutate, { MutationController } from 'dom-mutator';
 
 import { MessageBus } from './message-bus';
 import { showPreviewModeModal } from './preview/preview';
+import { createConsentAwareUserProvider } from './providers/consent-aware-user-provider';
 import { ConsentAwareStorage } from './storage/consent-aware-storage';
 import { PageChangeEvent, SubscriptionManager } from './subscriptions';
 import {
@@ -155,6 +156,11 @@ export class DefaultWebExperimentClient implements WebExperimentClient {
       // eslint-disable-next-line @typescript-eslint/ban-ts-comment
       // @ts-ignore
       internalInstanceNameSuffix: 'web',
+      defaultUserProvider: createConsentAwareUserProvider(
+        this.storage,
+        config.userProvider,
+        this.apiKey,
+      ),
       initialFlags: initialFlagsString,
       // timeout for fetching remote flags
       fetchTimeoutMillis: 1000,
diff --git a/packages/experiment-tag/src/providers/consent-aware-user-provider.ts b/packages/experiment-tag/src/providers/consent-aware-user-provider.ts
new file mode 100644
index 00000000..4989e43c
--- /dev/null
+++ b/packages/experiment-tag/src/providers/consent-aware-user-provider.ts
@@ -0,0 +1,68 @@
+import {
+  DefaultUserProvider,
+  ExperimentUserProvider,
+} from '@amplitude/experiment-js-client';
+
+import { ConsentAwareStorage } from '../storage/consent-aware-storage';
+
+import { Storage } from './types';
+
+/**
+ * Factory function that creates a DefaultUserProvider with consent-aware storage implementations.
+ * This allows the DefaultUserProvider to respect consent status when storing/retrieving user data.
+ *
+ * @param consentAwareStorage - The ConsentAwareStorage instance to use for all storage operations
+ * @param userProvider - Optional nested user provider for additional user context
+ * @param apiKey - Optional API key for storage key generation
+ * @returns A DefaultUserProvider configured with consent-aware storage
+ */
+export function createConsentAwareUserProvider(
+  consentAwareStorage: ConsentAwareStorage,
+  userProvider?: ExperimentUserProvider,
+  apiKey?: string,
+): DefaultUserProvider {
+  return new DefaultUserProvider(
+    userProvider,
+    apiKey,
+    new ConsentAwareLocalStorage(consentAwareStorage),
+    new ConsentAwareSessionStorage(consentAwareStorage),
+  );
+}
+
+class ConsentAwareLocalStorage implements Storage {
+  constructor(private consentAwareStorage: ConsentAwareStorage) {}
+
+  get(key: string): string {
+    return this.consentAwareStorage.getItem<string>('localStorage', key) || '';
+  }
+
+  put(key: string, value: string): void {
+    this.consentAwareStorage.setItem('localStorage', key, value);
+  }
+
+  delete(key: string): void {
+    this.consentAwareStorage.removeItem('localStorage', key);
+  }
+}
+
+/**
+ * Adapter that implements the experiment-browser Storage interface
+ * using ConsentAwareStorage for sessionStorage operations
+ */
+class ConsentAwareSessionStorage implements Storage {
+  constructor(private consentAwareStorage: ConsentAwareStorage) {}
+
+  get(key: string): string {
+    return (
+      this.consentAwareStorage.getItem<string>('sessionStorage', key) || ''
+    );
+  }
+
+  put(key: string, value: string): void {
+    this.consentAwareStorage.setItem('sessionStorage', key, value);
+  }
+
+  delete(key: string): void {
+    this.consentAwareStorage.removeItem('sessionStorage', key);
+  }
+}
diff --git a/packages/experiment-tag/src/providers/types.ts b/packages/experiment-tag/src/providers/types.ts
new file mode 100644
index 00000000..943e63bf
--- /dev/null
+++ b/packages/experiment-tag/src/providers/types.ts
@@ -0,0 +1,5 @@
+export interface Storage {
+  get(key: string): string;
+  put(key: string, value: string): void;
+  delete(key: string): void;
+}
diff --git a/packages/experiment-tag/src/storage/consent-aware-storage.ts b/packages/experiment-tag/src/storage/consent-aware-storage.ts
index a716be1a..4ea7e01f 100644
--- a/packages/experiment-tag/src/storage/consent-aware-storage.ts
+++ b/packages/experiment-tag/src/storage/consent-aware-storage.ts
@@ -16,6 +16,7 @@ import {
  */
 export class ConsentAwareStorage {
   private inMemoryStorage: Map<StorageType, Map<string, unknown>> = new Map();
+  private inMemoryRawStorage: Map<StorageType, Map<string, string>> = new Map();
   private inMemoryMarketingCookies: Map<string, Campaign> = new Map();
   private consentStatus: ConsentStatus;
 
@@ -30,17 +31,31 @@ export class ConsentAwareStorage {
     this.consentStatus = consentStatus;
 
     if (consentStatus === ConsentStatus.GRANTED) {
+      // Persist JSON storage
       for (const [storageType, storageMap] of this.inMemoryStorage.entries()) {
         for (const [key, value] of storageMap.entries()) {
           try {
             const jsonString = JSON.stringify(value);
             getStorage(storageType)?.setItem(key, jsonString);
           } catch (error) {
-            console.warn(`Failed to persist data for key ${key}:`, error);
+            console.warn(`Failed to persist JSON data for key ${key}:`, error);
           }
         }
       }
       this.inMemoryStorage.clear();
+
+      // Persist raw string storage
+      for (const [storageType, storageMap] of this.inMemoryRawStorage.entries()) {
+        for (const [key, value] of storageMap.entries()) {
+          try {
+            getStorage(storageType)?.setItem(key, value);
+          } catch (error) {
+            console.warn(`Failed to persist raw data for key ${key}:`, error);
+          }
+        }
+      }
+      this.inMemoryRawStorage.clear();
+
       this.persistMarketingCookies().then();
     }
   }
@@ -102,19 +117,29 @@ export class ConsentAwareStorage {
    * Remove a value from storage with consent awareness
    */
   public removeItem(storageType: StorageType, key: string): void {
-    const storageMap = this.inMemoryStorage.get(storageType);
     if (this.consentStatus === ConsentStatus.GRANTED) {
       removeStorageItem(storageType, key);
       return;
     }
-    if (storageMap) {
-      storageMap.delete(key);
-      if (storageMap.size === 0) {
+
+    // Remove from JSON storage
+    const jsonStorageMap = this.inMemoryStorage.get(storageType);
+    if (jsonStorageMap) {
+      jsonStorageMap.delete(key);
+      if (jsonStorageMap.size === 0) {
         this.inMemoryStorage.delete(storageType);
       }
     }
-  }
 
+    // Remove from raw storage
+    const rawStorageMap = this.inMemoryRawStorage.get(storageType);
+    if (rawStorageMap) {
+      rawStorageMap.delete(key);
+      if (rawStorageMap.size === 0) {
+        this.inMemoryRawStorage.delete(storageType);
+      }
+    }
+  }
   /**
    * Set marketing cookie with consent awareness
    * Parses current campaign data from URL and referrer, then stores it in the marketing cookie

From a9ad66ad5d266f7c2a22dcdf178013008650d837 Mon Sep 17 00:00:00 2001
From: Tim Yiu <137842098+tyiuhc@users.noreply.github.com>
Date: Tue, 7 Oct 2025 14:05:15 -0700
Subject: [PATCH 02/14] remove raw storage

---
 .../src/storage/consent-aware-storage.ts      | 23 -------------------
 1 file changed, 23 deletions(-)

diff --git a/packages/experiment-tag/src/storage/consent-aware-storage.ts b/packages/experiment-tag/src/storage/consent-aware-storage.ts
index 4ea7e01f..a3d7e941 100644
--- a/packages/experiment-tag/src/storage/consent-aware-storage.ts
+++ b/packages/experiment-tag/src/storage/consent-aware-storage.ts
@@ -16,7 +16,6 @@ import {
  */
 export class ConsentAwareStorage {
   private inMemoryStorage: Map<StorageType, Map<string, unknown>> = new Map();
-  private inMemoryRawStorage: Map<StorageType, Map<string, string>> = new Map();
   private inMemoryMarketingCookies: Map<string, Campaign> = new Map();
   private consentStatus: ConsentStatus;
 
@@ -43,19 +42,6 @@ export class ConsentAwareStorage {
         }
       }
       this.inMemoryStorage.clear();
-
-      // Persist raw string storage
-      for (const [storageType, storageMap] of this.inMemoryRawStorage.entries()) {
-        for (const [key, value] of storageMap.entries()) {
-          try {
-            getStorage(storageType)?.setItem(key, value);
-          } catch (error) {
-            console.warn(`Failed to persist raw data for key ${key}:`, error);
-          }
-        }
-      }
-      this.inMemoryRawStorage.clear();
-
       this.persistMarketingCookies().then();
     }
   }
@@ -130,15 +116,6 @@ export class ConsentAwareStorage {
         this.inMemoryStorage.delete(storageType);
       }
     }
-
-    // Remove from raw storage
-    const rawStorageMap = this.inMemoryRawStorage.get(storageType);
-    if (rawStorageMap) {
-      rawStorageMap.delete(key);
-      if (rawStorageMap.size === 0) {
-        this.inMemoryRawStorage.delete(storageType);
-      }
-    }
   }
   /**
    * Set marketing cookie with consent awareness

From 990d4df9755f66a8c7a03373a1ee1ae25a68e8cb Mon Sep 17 00:00:00 2001
From: Tim Yiu <137842098+tyiuhc@users.noreply.github.com>
Date: Tue, 7 Oct 2025 15:36:21 -0700
Subject: [PATCH 03/14] fix factory test

---
 packages/experiment-browser/src/factory.ts               | 2 +-
 .../experiment-tag/src/storage/consent-aware-storage.ts  | 9 ---------
 2 files changed, 1 insertion(+), 10 deletions(-)

diff --git a/packages/experiment-browser/src/factory.ts b/packages/experiment-browser/src/factory.ts
index ac069b1f..168767f0 100644
--- a/packages/experiment-browser/src/factory.ts
+++ b/packages/experiment-browser/src/factory.ts
@@ -74,7 +74,7 @@ const newExperimentClient = (
     userProvider:
       // eslint-disable-next-line @typescript-eslint/ban-ts-comment
       // @ts-ignore
-      config.defaultUserProvider ??
+      config?.defaultUserProvider ??
       new DefaultUserProvider(config?.userProvider, apiKey),
   });
 };
diff --git a/packages/experiment-tag/src/storage/consent-aware-storage.ts b/packages/experiment-tag/src/storage/consent-aware-storage.ts
index a3d7e941..06913e8b 100644
--- a/packages/experiment-tag/src/storage/consent-aware-storage.ts
+++ b/packages/experiment-tag/src/storage/consent-aware-storage.ts
@@ -107,15 +107,6 @@ export class ConsentAwareStorage {
       removeStorageItem(storageType, key);
       return;
     }
-
-    // Remove from JSON storage
-    const jsonStorageMap = this.inMemoryStorage.get(storageType);
-    if (jsonStorageMap) {
-      jsonStorageMap.delete(key);
-      if (jsonStorageMap.size === 0) {
-        this.inMemoryStorage.delete(storageType);
-      }
-    }
   }
   /**
    * Set marketing cookie with consent awareness

From 953e381ed5dede276fdb351a1036e3df55929040 Mon Sep 17 00:00:00 2001
From: Tim Yiu <137842098+tyiuhc@users.noreply.github.com>
Date: Tue, 7 Oct 2025 15:41:29 -0700
Subject: [PATCH 04/14] fix consent aware storage

---
 .../src/storage/consent-aware-storage.ts              | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/packages/experiment-tag/src/storage/consent-aware-storage.ts b/packages/experiment-tag/src/storage/consent-aware-storage.ts
index 06913e8b..a716be1a 100644
--- a/packages/experiment-tag/src/storage/consent-aware-storage.ts
+++ b/packages/experiment-tag/src/storage/consent-aware-storage.ts
@@ -30,14 +30,13 @@ export class ConsentAwareStorage {
     this.consentStatus = consentStatus;
 
     if (consentStatus === ConsentStatus.GRANTED) {
-      // Persist JSON storage
       for (const [storageType, storageMap] of this.inMemoryStorage.entries()) {
         for (const [key, value] of storageMap.entries()) {
           try {
             const jsonString = JSON.stringify(value);
             getStorage(storageType)?.setItem(key, jsonString);
           } catch (error) {
-            console.warn(`Failed to persist JSON data for key ${key}:`, error);
+            console.warn(`Failed to persist data for key ${key}:`, error);
           }
         }
       }
@@ -103,11 +102,19 @@ export class ConsentAwareStorage {
    * Remove a value from storage with consent awareness
    */
   public removeItem(storageType: StorageType, key: string): void {
+    const storageMap = this.inMemoryStorage.get(storageType);
     if (this.consentStatus === ConsentStatus.GRANTED) {
       removeStorageItem(storageType, key);
       return;
     }
+    if (storageMap) {
+      storageMap.delete(key);
+      if (storageMap.size === 0) {
+        this.inMemoryStorage.delete(storageType);
+      }
+    }
   }
+
   /**
    * Set marketing cookie with consent awareness
    * Parses current campaign data from URL and referrer, then stores it in the marketing cookie

From 045956d50473f35372529fb98e4f129b9d38a931 Mon Sep 17 00:00:00 2001
From: Tim Yiu <137842098+tyiuhc@users.noreply.github.com>
Date: Tue, 7 Oct 2025 15:43:45 -0700
Subject: [PATCH 05/14] mandatory api key

---
 packages/experiment-tag/src/experiment.ts                     | 2 +-
 .../src/providers/consent-aware-user-provider.ts              | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/experiment-tag/src/experiment.ts b/packages/experiment-tag/src/experiment.ts
index a0671e22..f09b8be8 100644
--- a/packages/experiment-tag/src/experiment.ts
+++ b/packages/experiment-tag/src/experiment.ts
@@ -158,8 +158,8 @@ export class DefaultWebExperimentClient implements WebExperimentClient {
       internalInstanceNameSuffix: 'web',
       defaultUserProvider: createConsentAwareUserProvider(
         this.storage,
-        config.userProvider,
         this.apiKey,
+        config.userProvider,
       ),
       initialFlags: initialFlagsString,
       // timeout for fetching remote flags
diff --git a/packages/experiment-tag/src/providers/consent-aware-user-provider.ts b/packages/experiment-tag/src/providers/consent-aware-user-provider.ts
index 4989e43c..1c7d13dc 100644
--- a/packages/experiment-tag/src/providers/consent-aware-user-provider.ts
+++ b/packages/experiment-tag/src/providers/consent-aware-user-provider.ts
@@ -13,13 +13,13 @@ import { Storage } from './types';
  *
  * @param consentAwareStorage - The ConsentAwareStorage instance to use for all storage operations
  * @param userProvider - Optional nested user provider for additional user context
- * @param apiKey - Optional API key for storage key generation
+ * @param apiKey - API key for storage key generation
  * @returns A DefaultUserProvider configured with consent-aware storage
  */
 export function createConsentAwareUserProvider(
   consentAwareStorage: ConsentAwareStorage,
+  apiKey: string,
   userProvider?: ExperimentUserProvider,
-  apiKey?: string,
 ): DefaultUserProvider {
   return new DefaultUserProvider(
     userProvider,

From b48c693dcf07e482cfb84294fbec5ca61aca0f07 Mon Sep 17 00:00:00 2001
From: Tim Yiu <137842098+tyiuhc@users.noreply.github.com>
Date: Tue, 7 Oct 2025 15:59:27 -0700
Subject: [PATCH 06/14] simplify

---
 packages/experiment-browser/src/factory.ts    | 14 +++-
 packages/experiment-tag/src/experiment.ts     | 16 +++--
 .../providers/consent-aware-user-provider.ts  | 68 -------------------
 .../experiment-tag/src/providers/types.ts     |  5 --
 .../src/storage/consent-aware-storage.ts      | 35 ++++++++++
 5 files changed, 56 insertions(+), 82 deletions(-)
 delete mode 100644 packages/experiment-tag/src/providers/consent-aware-user-provider.ts
 delete mode 100644 packages/experiment-tag/src/providers/types.ts

diff --git a/packages/experiment-browser/src/factory.ts b/packages/experiment-browser/src/factory.ts
index 168767f0..ccf4007d 100644
--- a/packages/experiment-browser/src/factory.ts
+++ b/packages/experiment-browser/src/factory.ts
@@ -74,8 +74,18 @@ const newExperimentClient = (
     userProvider:
       // eslint-disable-next-line @typescript-eslint/ban-ts-comment
       // @ts-ignore
-      config?.defaultUserProvider ??
-      new DefaultUserProvider(config?.userProvider, apiKey),
+      config?.consentAwareStorage
+        ? new DefaultUserProvider(
+            config?.userProvider,
+            apiKey,
+            // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+            // @ts-ignore
+            config?.consentAwareStorage.localStorage,
+            // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+            // @ts-ignore
+            config?.consentAwareStorage.sessionStorage,
+          )
+        : new DefaultUserProvider(config?.userProvider, apiKey),
   });
 };
 
diff --git a/packages/experiment-tag/src/experiment.ts b/packages/experiment-tag/src/experiment.ts
index f09b8be8..5d3ee904 100644
--- a/packages/experiment-tag/src/experiment.ts
+++ b/packages/experiment-tag/src/experiment.ts
@@ -17,8 +17,11 @@ import mutate, { MutationController } from 'dom-mutator';
 
 import { MessageBus } from './message-bus';
 import { showPreviewModeModal } from './preview/preview';
-import { createConsentAwareUserProvider } from './providers/consent-aware-user-provider';
-import { ConsentAwareStorage } from './storage/consent-aware-storage';
+import {
+  ConsentAwareLocalStorage,
+  ConsentAwareSessionStorage,
+  ConsentAwareStorage,
+} from './storage/consent-aware-storage';
 import { PageChangeEvent, SubscriptionManager } from './subscriptions';
 import {
   ConsentOptions,
@@ -156,11 +159,10 @@ export class DefaultWebExperimentClient implements WebExperimentClient {
       // eslint-disable-next-line @typescript-eslint/ban-ts-comment
       // @ts-ignore
       internalInstanceNameSuffix: 'web',
-      defaultUserProvider: createConsentAwareUserProvider(
-        this.storage,
-        this.apiKey,
-        config.userProvider,
-      ),
+      consentAwareStorage: {
+        localStorage: new ConsentAwareLocalStorage(this.storage),
+        sessionStorage: new ConsentAwareSessionStorage(this.storage),
+      },
       initialFlags: initialFlagsString,
       // timeout for fetching remote flags
       fetchTimeoutMillis: 1000,
diff --git a/packages/experiment-tag/src/providers/consent-aware-user-provider.ts b/packages/experiment-tag/src/providers/consent-aware-user-provider.ts
deleted file mode 100644
index 1c7d13dc..00000000
--- a/packages/experiment-tag/src/providers/consent-aware-user-provider.ts
+++ /dev/null
@@ -1,68 +0,0 @@
-import {
-  DefaultUserProvider,
-  ExperimentUserProvider,
-} from '@amplitude/experiment-js-client';
-
-import { ConsentAwareStorage } from '../storage/consent-aware-storage';
-
-import { Storage } from './types';
-
-/**
- * Factory function that creates a DefaultUserProvider with consent-aware storage implementations.
- * This allows the DefaultUserProvider to respect consent status when storing/retrieving user data.
- *
- * @param consentAwareStorage - The ConsentAwareStorage instance to use for all storage operations
- * @param userProvider - Optional nested user provider for additional user context
- * @param apiKey - API key for storage key generation
- * @returns A DefaultUserProvider configured with consent-aware storage
- */
-export function createConsentAwareUserProvider(
-  consentAwareStorage: ConsentAwareStorage,
-  apiKey: string,
-  userProvider?: ExperimentUserProvider,
-): DefaultUserProvider {
-  return new DefaultUserProvider(
-    userProvider,
-    apiKey,
-    new ConsentAwareLocalStorage(consentAwareStorage),
-    new ConsentAwareSessionStorage(consentAwareStorage),
-  );
-}
-
-class ConsentAwareLocalStorage implements Storage {
-  constructor(private consentAwareStorage: ConsentAwareStorage) {}
-
-  get(key: string): string {
-    return this.consentAwareStorage.getItem<string>('localStorage', key) || '';
-  }
-
-  put(key: string, value: string): void {
-    this.consentAwareStorage.setItem('localStorage', key, value);
-  }
-
-  delete(key: string): void {
-    this.consentAwareStorage.removeItem('localStorage', key);
-  }
-}
-
-/**
- * Adapter that implements the experiment-browser Storage interface
- * using ConsentAwareStorage for sessionStorage operations
- */
-class ConsentAwareSessionStorage implements Storage {
-  constructor(private consentAwareStorage: ConsentAwareStorage) {}
-
-  get(key: string): string {
-    return (
-      this.consentAwareStorage.getItem<string>('sessionStorage', key) || ''
-    );
-  }
-
-  put(key: string, value: string): void {
-    this.consentAwareStorage.setItem('sessionStorage', key, value);
-  }
-
-  delete(key: string): void {
-    this.consentAwareStorage.removeItem('sessionStorage', key);
-  }
-}
diff --git a/packages/experiment-tag/src/providers/types.ts b/packages/experiment-tag/src/providers/types.ts
deleted file mode 100644
index 943e63bf..00000000
--- a/packages/experiment-tag/src/providers/types.ts
+++ /dev/null
@@ -1,5 +0,0 @@
-export interface Storage {
-  get(key: string): string;
-  put(key: string, value: string): void;
-  delete(key: string): void;
-}
diff --git a/packages/experiment-tag/src/storage/consent-aware-storage.ts b/packages/experiment-tag/src/storage/consent-aware-storage.ts
index a716be1a..40fbc1a0 100644
--- a/packages/experiment-tag/src/storage/consent-aware-storage.ts
+++ b/packages/experiment-tag/src/storage/consent-aware-storage.ts
@@ -138,3 +138,38 @@ export class ConsentAwareStorage {
     }
   }
 }
+
+export class ConsentAwareLocalStorage {
+  constructor(private consentAwareStorage: ConsentAwareStorage) {}
+
+  get(key: string): string {
+    return this.consentAwareStorage.getItem<string>('localStorage', key) || '';
+  }
+
+  put(key: string, value: string): void {
+    this.consentAwareStorage.setItem('localStorage', key, value);
+  }
+
+  delete(key: string): void {
+    this.consentAwareStorage.removeItem('localStorage', key);
+  }
+}
+
+export class ConsentAwareSessionStorage {
+  constructor(private consentAwareStorage: ConsentAwareStorage) {}
+
+  get(key: string): string {
+    return (
+      this.consentAwareStorage.getItem<string>('sessionStorage', key) || ''
+    );
+  }
+
+  put(key: string, value: string): void {
+    this.consentAwareStorage.setItem('sessionStorage', key, value);
+  }
+
+  delete(key: string): void {
+    this.consentAwareStorage.removeItem('sessionStorage', key);
+  }
+}
+

From 9a64fc75cb78f09e15ef6050ad05416d410a3c92 Mon Sep 17 00:00:00 2001
From: Tim Yiu <137842098+tyiuhc@users.noreply.github.com>
Date: Tue, 7 Oct 2025 16:02:45 -0700
Subject: [PATCH 07/14] remove unused export

---
 packages/experiment-browser/src/factory.ts               | 9 +++------
 packages/experiment-browser/src/index.ts                 | 1 -
 .../experiment-tag/src/storage/consent-aware-storage.ts  | 1 -
 3 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/packages/experiment-browser/src/factory.ts b/packages/experiment-browser/src/factory.ts
index ccf4007d..e9de00fa 100644
--- a/packages/experiment-browser/src/factory.ts
+++ b/packages/experiment-browser/src/factory.ts
@@ -72,17 +72,14 @@ const newExperimentClient = (
   return new ExperimentClient(apiKey, {
     ...config,
     userProvider:
-      // eslint-disable-next-line @typescript-eslint/ban-ts-comment
-      // @ts-ignore
+      // @ts-expect-error - consentAwareStorage not in type definition
       config?.consentAwareStorage
         ? new DefaultUserProvider(
             config?.userProvider,
             apiKey,
-            // eslint-disable-next-line @typescript-eslint/ban-ts-comment
-            // @ts-ignore
+            // @ts-expect-error - consentAwareStorage not in type definition
             config?.consentAwareStorage.localStorage,
-            // eslint-disable-next-line @typescript-eslint/ban-ts-comment
-            // @ts-ignore
+            // @ts-expect-error - consentAwareStorage not in type definition
             config?.consentAwareStorage.sessionStorage,
           )
         : new DefaultUserProvider(config?.userProvider, apiKey),
diff --git a/packages/experiment-browser/src/index.ts b/packages/experiment-browser/src/index.ts
index 7b54808d..f19e72a8 100644
--- a/packages/experiment-browser/src/index.ts
+++ b/packages/experiment-browser/src/index.ts
@@ -34,4 +34,3 @@ export {
   ExperimentPluginType,
   ExperimentEvent,
 } from './types/plugin';
-export { DefaultUserProvider } from './providers/default';
diff --git a/packages/experiment-tag/src/storage/consent-aware-storage.ts b/packages/experiment-tag/src/storage/consent-aware-storage.ts
index 40fbc1a0..8b6ede0e 100644
--- a/packages/experiment-tag/src/storage/consent-aware-storage.ts
+++ b/packages/experiment-tag/src/storage/consent-aware-storage.ts
@@ -172,4 +172,3 @@ export class ConsentAwareSessionStorage {
     this.consentAwareStorage.removeItem('sessionStorage', key);
   }
 }
-

From 490041790e7f4e7e09fad70b9870e433415de91b Mon Sep 17 00:00:00 2001
From: Tim Yiu <137842098+tyiuhc@users.noreply.github.com>
Date: Tue, 7 Oct 2025 16:05:57 -0700
Subject: [PATCH 08/14] initialize experimentClient with consent-aware
 sessionstorage

---
 packages/experiment-browser/src/experimentClient.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/experiment-browser/src/experimentClient.ts b/packages/experiment-browser/src/experimentClient.ts
index eb8157cd..2ddff2a7 100644
--- a/packages/experiment-browser/src/experimentClient.ts
+++ b/packages/experiment-browser/src/experimentClient.ts
@@ -176,7 +176,8 @@ export class ExperimentClient implements Client {
       ? `${this.config.instanceName}-${internalInstanceName}`
       : this.config.instanceName;
     if (this.isWebExperiment) {
-      storage = new SessionStorage();
+      // @ts-expect-error - consentAwareStorage not in type definition
+      storage = config.consentAwareStorage.sessionStorage;
     } else {
       storage = new LocalStorage();
     }

From 5668549fa74c8e92d2b84e3d69a4511414446ee8 Mon Sep 17 00:00:00 2001
From: Tim Yiu <137842098+tyiuhc@users.noreply.github.com>
Date: Wed, 8 Oct 2025 13:46:10 -0700
Subject: [PATCH 09/14] fix tests and storage method

---
 packages/experiment-tag/src/experiment.ts     | 16 +++-
 .../src/storage/consent-aware-storage.ts      | 75 ++++++++++++++-----
 .../experiment-tag/src/storage/storage.ts     | 57 ++++++++------
 packages/experiment-tag/src/util/messenger.ts |  7 +-
 packages/experiment-tag/src/util/url.ts       | 13 ++--
 .../experiment-tag/test/experiment.test.ts    | 38 ++++------
 6 files changed, 127 insertions(+), 79 deletions(-)

diff --git a/packages/experiment-tag/src/experiment.ts b/packages/experiment-tag/src/experiment.ts
index 5d3ee904..c3969d58 100644
--- a/packages/experiment-tag/src/experiment.ts
+++ b/packages/experiment-tag/src/experiment.ts
@@ -22,6 +22,10 @@ import {
   ConsentAwareSessionStorage,
   ConsentAwareStorage,
 } from './storage/consent-aware-storage';
+import {
+  getAndParseStorageItem,
+  setAndStringifyStorageItem,
+} from './storage/storage';
 import { PageChangeEvent, SubscriptionManager } from './subscriptions';
 import {
   ConsentOptions,
@@ -878,9 +882,13 @@ export class DefaultWebExperimentClient implements WebExperimentClient {
         }
       });
 
-      this.storage.setItem('sessionStorage', PREVIEW_MODE_SESSION_KEY, {
-        previewFlags: this.previewFlags,
-      });
+      setAndStringifyStorageItem<PreviewState>(
+        'sessionStorage',
+        PREVIEW_MODE_SESSION_KEY,
+        {
+          previewFlags: this.previewFlags,
+        },
+      );
       const previewParamsToRemove = [
         ...Object.keys(this.previewFlags),
         PREVIEW_MODE_PARAM,
@@ -896,7 +904,7 @@ export class DefaultWebExperimentClient implements WebExperimentClient {
       // if in preview mode, listen for ForceVariant messages
       WindowMessenger.setup();
     } else {
-      const previewState: PreviewState | null = this.storage.getItem(
+      const previewState = getAndParseStorageItem<PreviewState>(
         'sessionStorage',
         PREVIEW_MODE_SESSION_KEY,
       );
diff --git a/packages/experiment-tag/src/storage/consent-aware-storage.ts b/packages/experiment-tag/src/storage/consent-aware-storage.ts
index 8b6ede0e..abeef085 100644
--- a/packages/experiment-tag/src/storage/consent-aware-storage.ts
+++ b/packages/experiment-tag/src/storage/consent-aware-storage.ts
@@ -4,10 +4,11 @@ import type { Campaign } from '@amplitude/analytics-core';
 import { ConsentStatus } from '../types';
 
 import {
-  getStorage,
-  getStorageItem,
+  getAndParseStorageItem,
+  getRawStorageItem,
   removeStorageItem,
-  setStorageItem,
+  setAndStringifyStorageItem,
+  setRawStorageItem,
   StorageType,
 } from './storage';
 
@@ -16,6 +17,7 @@ import {
  */
 export class ConsentAwareStorage {
   private inMemoryStorage: Map<StorageType, Map<string, unknown>> = new Map();
+  private inMemoryRawStorage: Map<StorageType, Map<string, string>> = new Map();
   private inMemoryMarketingCookies: Map<string, Campaign> = new Map();
   private consentStatus: ConsentStatus;
 
@@ -32,15 +34,19 @@ export class ConsentAwareStorage {
     if (consentStatus === ConsentStatus.GRANTED) {
       for (const [storageType, storageMap] of this.inMemoryStorage.entries()) {
         for (const [key, value] of storageMap.entries()) {
-          try {
-            const jsonString = JSON.stringify(value);
-            getStorage(storageType)?.setItem(key, jsonString);
-          } catch (error) {
-            console.warn(`Failed to persist data for key ${key}:`, error);
-          }
+          setAndStringifyStorageItem(storageType, key, value);
+        }
+      }
+      for (const [
+        storageType,
+        storageMap,
+      ] of this.inMemoryRawStorage.entries()) {
+        for (const [key, value] of storageMap.entries()) {
+          setRawStorageItem(storageType, key, value);
         }
       }
       this.inMemoryStorage.clear();
+      this.inMemoryRawStorage.clear();
       this.persistMarketingCookies().then();
     }
   }
@@ -73,7 +79,8 @@ export class ConsentAwareStorage {
    */
   public getItem<T>(storageType: StorageType, key: string): T | null {
     if (this.consentStatus === ConsentStatus.GRANTED) {
-      return getStorageItem(storageType, key);
+      const value = getAndParseStorageItem(storageType, key);
+      return value as T;
     }
 
     const storageMap = this.inMemoryStorage.get(storageType);
@@ -89,7 +96,7 @@ export class ConsentAwareStorage {
    */
   public setItem(storageType: StorageType, key: string, value: unknown): void {
     if (this.consentStatus === ConsentStatus.GRANTED) {
-      setStorageItem(storageType, key, value);
+      setAndStringifyStorageItem(storageType, key, value);
     } else {
       if (!this.inMemoryStorage.has(storageType)) {
         this.inMemoryStorage.set(storageType, new Map());
@@ -115,6 +122,42 @@ export class ConsentAwareStorage {
     }
   }
 
+  /**
+   * Get a raw string value from storage with consent awareness
+   * This is used by Storage interface implementations that expect raw strings
+   */
+  public getRawItem(storageType: StorageType, key: string): string {
+    if (this.consentStatus === ConsentStatus.GRANTED) {
+      return getRawStorageItem(storageType, key);
+    }
+
+    const storageMap = this.inMemoryRawStorage.get(storageType);
+    if (storageMap && storageMap.has(key)) {
+      return storageMap.get(key) || '';
+    }
+
+    return '';
+  }
+
+  /**
+   * Set a raw string value in storage with consent awareness
+   * This is used by Storage interface implementations that work with raw strings
+   */
+  public setRawItem(
+    storageType: StorageType,
+    key: string,
+    value: string,
+  ): void {
+    if (this.consentStatus === ConsentStatus.GRANTED) {
+      setRawStorageItem(storageType, key, value);
+    } else {
+      if (!this.inMemoryRawStorage.has(storageType)) {
+        this.inMemoryRawStorage.set(storageType, new Map());
+      }
+      this.inMemoryRawStorage.get(storageType)?.set(key, value);
+    }
+  }
+
   /**
    * Set marketing cookie with consent awareness
    * Parses current campaign data from URL and referrer, then stores it in the marketing cookie
@@ -143,11 +186,11 @@ export class ConsentAwareLocalStorage {
   constructor(private consentAwareStorage: ConsentAwareStorage) {}
 
   get(key: string): string {
-    return this.consentAwareStorage.getItem<string>('localStorage', key) || '';
+    return this.consentAwareStorage.getRawItem('localStorage', key);
   }
 
   put(key: string, value: string): void {
-    this.consentAwareStorage.setItem('localStorage', key, value);
+    this.consentAwareStorage.setRawItem('localStorage', key, value);
   }
 
   delete(key: string): void {
@@ -159,13 +202,11 @@ export class ConsentAwareSessionStorage {
   constructor(private consentAwareStorage: ConsentAwareStorage) {}
 
   get(key: string): string {
-    return (
-      this.consentAwareStorage.getItem<string>('sessionStorage', key) || ''
-    );
+    return this.consentAwareStorage.getRawItem('sessionStorage', key);
   }
 
   put(key: string, value: string): void {
-    this.consentAwareStorage.setItem('sessionStorage', key, value);
+    this.consentAwareStorage.setRawItem('sessionStorage', key, value);
   }
 
   delete(key: string): void {
diff --git a/packages/experiment-tag/src/storage/storage.ts b/packages/experiment-tag/src/storage/storage.ts
index 29f19644..0c05433f 100644
--- a/packages/experiment-tag/src/storage/storage.ts
+++ b/packages/experiment-tag/src/storage/storage.ts
@@ -3,43 +3,54 @@ import { getGlobalScope } from '@amplitude/experiment-core';
 export type StorageType = 'localStorage' | 'sessionStorage';
 
 /**
- * Get a JSON value from storage and parse it
+ * Get a JSON value from storage
  * @param storageType - The type of storage to use ('localStorage' or 'sessionStorage')
- * @param key - The key to retrieve
- * @returns The parsed JSON value or null if not found or invalid JSON
+ * @param key - The key to retrieve the value for
+ * @returns The JSON string value, or null if not found
  */
-export const getStorageItem = <T>(
+export const getRawStorageItem = <T>(
+  storageType: StorageType,
+  key: string,
+): string => {
+  return getStorage(storageType)?.getItem(key) || '';
+};
+
+/**
+ * Set a JSON value in storage
+ * @param storageType - The type of storage to use ('localStorage' or 'sessionStorage')
+ * @param key - The key to set the value for
+ * @param value - The value to set
+ */
+export const setRawStorageItem = (
+  storageType: StorageType,
+  key: string,
+  value: string,
+): void => {
+  getStorage(storageType)?.setItem(key, value);
+};
+
+export const getAndParseStorageItem = <T>(
   storageType: StorageType,
   key: string,
 ): T | null => {
+  const value = getRawStorageItem(storageType, key);
   try {
-    const value = getStorage(storageType)?.getItem(key);
-    if (!value) {
-      return null;
-    }
-    return JSON.parse(value) as T;
-  } catch (error) {
-    console.warn(`Failed to get and parse JSON from ${storageType}:`, error);
+    return JSON.parse(value);
+  } catch {
     return null;
   }
 };
 
-/**
- * Set a JSON value in storage by stringifying it
- * @param storageType - The type of storage to use ('localStorage' or 'sessionStorage')
- * @param key - The key to store the value under
- * @param value - The value to stringify and store
- */
-export const setStorageItem = (
+export const setAndStringifyStorageItem = <T>(
   storageType: StorageType,
   key: string,
-  value: unknown,
+  value: T,
 ): void => {
   try {
-    const jsonString = JSON.stringify(value);
-    getStorage(storageType)?.setItem(key, jsonString);
+    const stringValue = JSON.stringify(value);
+    setRawStorageItem(storageType, key, stringValue);
   } catch (error) {
-    console.warn(`Failed to stringify and set JSON in ${storageType}:`, error);
+    console.warn(`Failed to persist data for key ${key}:`, error);
   }
 };
 
@@ -59,7 +70,7 @@ export const removeStorageItem = (
   }
 };
 
-export const getStorage = (storageType: StorageType): Storage | null => {
+const getStorage = (storageType: StorageType): Storage | null => {
   const globalScope = getGlobalScope();
   if (!globalScope) {
     return null;
diff --git a/packages/experiment-tag/src/util/messenger.ts b/packages/experiment-tag/src/util/messenger.ts
index 1cf0bb19..8e754a51 100644
--- a/packages/experiment-tag/src/util/messenger.ts
+++ b/packages/experiment-tag/src/util/messenger.ts
@@ -1,6 +1,6 @@
 import { getGlobalScope } from '@amplitude/experiment-core';
 
-import { getStorageItem } from '../storage/storage';
+import { getAndParseStorageItem } from '../storage/storage';
 
 interface VisualEditorSession {
   injectSrc: string;
@@ -73,10 +73,11 @@ export class WindowMessenger {
    * Retrieve stored session data (read-only)
    */
   private static getStoredSession(): VisualEditorSession | null {
-    const sessionData = getStorageItem<VisualEditorSession>(
+    const sessionData = getAndParseStorageItem<VisualEditorSession>(
       'sessionStorage',
       VISUAL_EDITOR_SESSION_KEY,
-    );
+    ) as VisualEditorSession;
+
     if (!sessionData) {
       return null;
     }
diff --git a/packages/experiment-tag/src/util/url.ts b/packages/experiment-tag/src/util/url.ts
index 12089f27..e03c4789 100644
--- a/packages/experiment-tag/src/util/url.ts
+++ b/packages/experiment-tag/src/util/url.ts
@@ -1,7 +1,7 @@
 import { getGlobalScope } from '@amplitude/experiment-core';
 
 import { PREVIEW_MODE_PARAM, PREVIEW_MODE_SESSION_KEY } from '../experiment';
-import { getStorageItem } from '../storage/storage';
+import { getAndParseStorageItem, getRawStorageItem } from '../storage/storage';
 import { PreviewState } from '../types';
 
 export const getUrlParams = (): Record<string, string> => {
@@ -88,15 +88,12 @@ export const isPreviewMode = (): boolean => {
   if (getUrlParams()[PREVIEW_MODE_PARAM] === 'true') {
     return true;
   }
-  const previewState = getStorageItem(
+  const previewState = getAndParseStorageItem<PreviewState>(
     'sessionStorage',
     PREVIEW_MODE_SESSION_KEY,
-  ) as PreviewState;
-  if (
+  );
+  return !!(
     previewState?.previewFlags &&
     Object.keys(previewState.previewFlags).length > 0
-  ) {
-    return true;
-  }
-  return false;
+  );
 };
diff --git a/packages/experiment-tag/test/experiment.test.ts b/packages/experiment-tag/test/experiment.test.ts
index 1cdc7263..b546f44a 100644
--- a/packages/experiment-tag/test/experiment.test.ts
+++ b/packages/experiment-tag/test/experiment.test.ts
@@ -1507,28 +1507,18 @@ describe('initializeExperiment', () => {
   });
 
   describe('remote evaluation - flag already stored in session storage', () => {
-    const sessionStorageMock = () => {
-      let store = {};
-      return {
-        getItem: jest.fn((key) => store[key] || null),
-        setItem: jest.fn((key, value) => {
-          store[key] = value;
-        }),
-        removeItem: jest.fn((key) => {
-          delete store[key];
-        }),
-        clear: jest.fn(() => {
-          store = {};
-        }),
-      };
-    };
+    let testMockGlobal: any;
+
     beforeEach(() => {
-      Object.defineProperty(safeGlobal, 'sessionStorage', {
-        value: sessionStorageMock(),
+      // Create fresh mock global for each test in this describe block
+      testMockGlobal = newMockGlobal({
+        experimentConfig: {
+          consentOptions: {
+            status: ConsentStatus.GRANTED,
+          },
+        },
       });
-    });
-    afterEach(() => {
-      safeGlobal.sessionStorage.clear();
+      mockGetGlobalScope.mockReturnValue(testMockGlobal);
     });
     test('evaluated, applied, and impression tracked, start updates flag in storage, applied, impression deduped', async () => {
       const apiKey = 'api1';
@@ -1545,7 +1535,7 @@ describe('initializeExperiment', () => {
           flagVersion: 2,
         },
       );
-      safeGlobal.sessionStorage.setItem(
+      testMockGlobal.sessionStorage.setItem(
         storageKey,
         JSON.stringify({ test: storedFlag }),
       );
@@ -1592,7 +1582,7 @@ describe('initializeExperiment', () => {
       expect(mockExposure).toHaveBeenCalledTimes(1);
       // Check remote flag store in storage
       const flags = JSON.parse(
-        safeGlobal.sessionStorage.getItem(storageKey) as string,
+        testMockGlobal.sessionStorage.getItem(storageKey) as string,
       );
       expect(flags['test'].metadata.flagVersion).toEqual(4);
       expect(flags['test'].metadata.evaluationMode).toEqual('local');
@@ -1619,7 +1609,7 @@ describe('initializeExperiment', () => {
           flagVersion: 2,
         },
       );
-      safeGlobal.sessionStorage.setItem(
+      testMockGlobal.sessionStorage.setItem(
         storageKey,
         JSON.stringify({ test: storedFlag }),
       );
@@ -1674,7 +1664,7 @@ describe('initializeExperiment', () => {
       expect(mockExposure).toHaveBeenCalledTimes(2);
       // Check remote flag store in storage
       const flags = JSON.parse(
-        safeGlobal.sessionStorage.getItem(storageKey) as string,
+        testMockGlobal.sessionStorage.getItem(storageKey) as string,
       );
       expect(flags['test'].metadata.flagVersion).toEqual(4);
       expect(flags['test'].metadata.evaluationMode).toEqual('local');

From f923423bbe0eaf50bb00a901016115265813ca1a Mon Sep 17 00:00:00 2001
From: Tim Yiu <137842098+tyiuhc@users.noreply.github.com>
Date: Wed, 8 Oct 2025 13:49:42 -0700
Subject: [PATCH 10/14] simplify

---
 packages/experiment-tag/src/storage/storage.ts  | 6 +++---
 packages/experiment-tag/test/experiment.test.ts | 1 -
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/packages/experiment-tag/src/storage/storage.ts b/packages/experiment-tag/src/storage/storage.ts
index 0c05433f..e18948a7 100644
--- a/packages/experiment-tag/src/storage/storage.ts
+++ b/packages/experiment-tag/src/storage/storage.ts
@@ -3,7 +3,7 @@ import { getGlobalScope } from '@amplitude/experiment-core';
 export type StorageType = 'localStorage' | 'sessionStorage';
 
 /**
- * Get a JSON value from storage
+ * Get a JSON string value from storage
  * @param storageType - The type of storage to use ('localStorage' or 'sessionStorage')
  * @param key - The key to retrieve the value for
  * @returns The JSON string value, or null if not found
@@ -16,10 +16,10 @@ export const getRawStorageItem = <T>(
 };
 
 /**
- * Set a JSON value in storage
+ * Set a JSON string value in storage
  * @param storageType - The type of storage to use ('localStorage' or 'sessionStorage')
  * @param key - The key to set the value for
- * @param value - The value to set
+ * @param value - The JSON string value to set
  */
 export const setRawStorageItem = (
   storageType: StorageType,
diff --git a/packages/experiment-tag/test/experiment.test.ts b/packages/experiment-tag/test/experiment.test.ts
index b546f44a..35ec7536 100644
--- a/packages/experiment-tag/test/experiment.test.ts
+++ b/packages/experiment-tag/test/experiment.test.ts
@@ -1510,7 +1510,6 @@ describe('initializeExperiment', () => {
     let testMockGlobal: any;
 
     beforeEach(() => {
-      // Create fresh mock global for each test in this describe block
       testMockGlobal = newMockGlobal({
         experimentConfig: {
           consentOptions: {

From 36cbe46b7e62fd6ce94336c11347b49a828609a8 Mon Sep 17 00:00:00 2001
From: Tim Yiu <137842098+tyiuhc@users.noreply.github.com>
Date: Tue, 14 Oct 2025 14:25:57 -0700
Subject: [PATCH 11/14] simplify factory

---
 packages/experiment-browser/src/factory.ts | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/packages/experiment-browser/src/factory.ts b/packages/experiment-browser/src/factory.ts
index e9de00fa..9edcb308 100644
--- a/packages/experiment-browser/src/factory.ts
+++ b/packages/experiment-browser/src/factory.ts
@@ -71,18 +71,14 @@ const newExperimentClient = (
 ): ExperimentClient => {
   return new ExperimentClient(apiKey, {
     ...config,
-    userProvider:
-      // @ts-expect-error - consentAwareStorage not in type definition
-      config?.consentAwareStorage
-        ? new DefaultUserProvider(
-            config?.userProvider,
-            apiKey,
-            // @ts-expect-error - consentAwareStorage not in type definition
-            config?.consentAwareStorage.localStorage,
-            // @ts-expect-error - consentAwareStorage not in type definition
-            config?.consentAwareStorage.sessionStorage,
-          )
-        : new DefaultUserProvider(config?.userProvider, apiKey),
+    userProvider: config?.['consentAwareStorage']
+      ? new DefaultUserProvider(
+          config?.userProvider,
+          apiKey,
+          config?.['consentAwareStorage']?.['localStorage'],
+          config?.['consentAwareStorage']?.['sessionStorage'],
+        )
+      : new DefaultUserProvider(config?.userProvider, apiKey),
   });
 };
 

From b69b86298cb469a9afa5f6ea4662d3c12db5c1be Mon Sep 17 00:00:00 2001
From: Tim Yiu <137842098+tyiuhc@users.noreply.github.com>
Date: Tue, 14 Oct 2025 14:41:30 -0700
Subject: [PATCH 12/14] simplify init

---
 packages/experiment-browser/src/experimentClient.ts | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/packages/experiment-browser/src/experimentClient.ts b/packages/experiment-browser/src/experimentClient.ts
index 2ddff2a7..ff079b4c 100644
--- a/packages/experiment-browser/src/experimentClient.ts
+++ b/packages/experiment-browser/src/experimentClient.ts
@@ -176,8 +176,7 @@ export class ExperimentClient implements Client {
       ? `${this.config.instanceName}-${internalInstanceName}`
       : this.config.instanceName;
     if (this.isWebExperiment) {
-      // @ts-expect-error - consentAwareStorage not in type definition
-      storage = config.consentAwareStorage.sessionStorage;
+      storage = config?.['consentAwareStorage']?.['sessionStorage'];
     } else {
       storage = new LocalStorage();
     }

From 7c31cdc3a3b61f3370a2c172cdb23fd2903d51ac Mon Sep 17 00:00:00 2001
From: Tim Yiu <137842098+tyiuhc@users.noreply.github.com>
Date: Wed, 15 Oct 2025 15:03:25 -0700
Subject: [PATCH 13/14] Update packages/experiment-browser/src/factory.ts

Co-authored-by: Stephen Choi <106711294+stephen-choi-amplitude@users.noreply.github.com>
---
 packages/experiment-browser/src/factory.ts | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/packages/experiment-browser/src/factory.ts b/packages/experiment-browser/src/factory.ts
index 9edcb308..2cd61f4a 100644
--- a/packages/experiment-browser/src/factory.ts
+++ b/packages/experiment-browser/src/factory.ts
@@ -71,14 +71,12 @@ const newExperimentClient = (
 ): ExperimentClient => {
   return new ExperimentClient(apiKey, {
     ...config,
-    userProvider: config?.['consentAwareStorage']
-      ? new DefaultUserProvider(
-          config?.userProvider,
-          apiKey,
-          config?.['consentAwareStorage']?.['localStorage'],
-          config?.['consentAwareStorage']?.['sessionStorage'],
-        )
-      : new DefaultUserProvider(config?.userProvider, apiKey),
+    userProvider: new DefaultUserProvider(
+      config?.userProvider,
+      apiKey,
+      config?.['consentAwareStorage']?.localStorage,
+      config?.['consentAwareStorage']?.sessionStorage,
+    ),
   });
 };
 

From 64fa6e6ea3df9de4ed54467deb882202cfb1e88c Mon Sep 17 00:00:00 2001
From: Tim Yiu <137842098+tyiuhc@users.noreply.github.com>
Date: Wed, 15 Oct 2025 15:29:55 -0700
Subject: [PATCH 14/14] simplify per comments

---
 packages/experiment-tag/src/util/url.ts | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/packages/experiment-tag/src/util/url.ts b/packages/experiment-tag/src/util/url.ts
index e03c4789..5d5bd66b 100644
--- a/packages/experiment-tag/src/util/url.ts
+++ b/packages/experiment-tag/src/util/url.ts
@@ -1,7 +1,7 @@
 import { getGlobalScope } from '@amplitude/experiment-core';
 
 import { PREVIEW_MODE_PARAM, PREVIEW_MODE_SESSION_KEY } from '../experiment';
-import { getAndParseStorageItem, getRawStorageItem } from '../storage/storage';
+import { getAndParseStorageItem } from '../storage/storage';
 import { PreviewState } from '../types';
 
 export const getUrlParams = (): Record<string, string> => {
@@ -92,8 +92,11 @@ export const isPreviewMode = (): boolean => {
     'sessionStorage',
     PREVIEW_MODE_SESSION_KEY,
   );
-  return !!(
-    previewState?.previewFlags &&
+  if (!previewState) {
+    return false;
+  }
+  return (
+    previewState.previewFlags &&
     Object.keys(previewState.previewFlags).length > 0
   );
 };