fix(browser-sdk): use noop storage fallback on server

Author: roncohen

packages/browser-sdk/src/storage.ts

@@ -1,20 +1,16 @@
+import { IS_SERVER } from "./config";
+
 export type StorageAdapter = {
   getItem(key: string): Promise<string | null>;
   setItem(key: string, value: string): Promise<void>;
   removeItem?(key: string): Promise<void>;
 };
 
-export function createMemoryStorageAdapter(): StorageAdapter {
-  const memoryStorage = new Map<string, string>();
-
+export function createNoopStorageAdapter(): StorageAdapter {
   return {
-    getItem: async (key) => memoryStorage.get(key) ?? null,
-    setItem: async (key, value) => {
-      memoryStorage.set(key, value);
-    },
-    removeItem: async (key) => {
-      memoryStorage.delete(key);
-    },
+    getItem: async () => null,
+    setItem: async () => undefined,
+    removeItem: async () => undefined,
   };
 }
 
@@ -40,9 +36,6 @@ export function getLocalStorageAdapter(): StorageAdapter {
 }
 
 export function getDefaultStorageAdapter(): StorageAdapter {
-  try {
-    return getLocalStorageAdapter();
-  } catch {
-    return createMemoryStorageAdapter();
-  }
+  if (IS_SERVER) return createNoopStorageAdapter();
+  return getLocalStorageAdapter();
 }

packages/browser-sdk/test/client.test.ts

@@ -27,21 +27,6 @@ describe("ReflagClient", () => {
     vi.unstubAllGlobals();
   });
 
-  describe("storage runtime compatibility", () => {
-    it("can be constructed without localStorage", () => {
-      vi.stubGlobal("localStorage", undefined);
-
-      expect(
-        () =>
-          new ReflagClient({
-            publishableKey: "test-key",
-            user: { id: "user1" },
-            company: { id: "company1" },
-          }),
-      ).not.toThrow();
-    });
-  });
-
   describe("updateUser", () => {
     it("should update the user context", async () => {
       // and send new user data and trigger flag update

packages/browser-sdk/test/storage.test.ts

@@ -1,39 +1,45 @@
 import { afterEach, describe, expect, it, vi } from "vitest";
 
-import {
-  createMemoryStorageAdapter,
-  getDefaultStorageAdapter,
-  getLocalStorageAdapter,
-} from "../src/storage";
+async function loadStorageModule() {
+  vi.resetModules();
+  return import("../src/storage");
+}
 
 describe("storage adapters", () => {
   afterEach(() => {
     vi.unstubAllGlobals();
   });
 
-  it("memory adapter stores and retrieves values", async () => {
-    const adapter = createMemoryStorageAdapter();
+  it("noop adapter ignores writes", async () => {
+    const { createNoopStorageAdapter } = await loadStorageModule();
+    const adapter = createNoopStorageAdapter();
 
     expect(await adapter.getItem("key")).toBeNull();
     await adapter.setItem("key", "value");
-    expect(await adapter.getItem("key")).toBe("value");
+    expect(await adapter.getItem("key")).toBeNull();
 
     await adapter.removeItem?.("key");
     expect(await adapter.getItem("key")).toBeNull();
   });
 
-  it("localStorage adapter throws when localStorage is unavailable", () => {
+  it("localStorage adapter throws when localStorage is unavailable", async () => {
+    const { getLocalStorageAdapter } = await loadStorageModule();
     vi.stubGlobal("localStorage", undefined);
     expect(() => getLocalStorageAdapter()).toThrowError(
       "localStorage is not available. Provide a custom storage adapter.",
     );
   });
 
-  it("default adapter falls back when localStorage is unavailable", async () => {
+  it("default adapter falls back to noop on server runtimes", async () => {
+    vi.resetModules();
+    vi.stubGlobal("window", undefined);
+    vi.stubGlobal("document", undefined);
     vi.stubGlobal("localStorage", undefined);
+
+    const { getDefaultStorageAdapter } = await import("../src/storage");
     const adapter = getDefaultStorageAdapter();
 
     await adapter.setItem("fallback", "ok");
-    expect(await adapter.getItem("fallback")).toBe("ok");
+    expect(await adapter.getItem("fallback")).toBeNull();
   });
 });