initialize the configuration store (#69)

* v3.0.2-rc.2

* initialize the configuration store

* add logging

* v3.0.2-rc.3

* remove console.log

* rc4

* return empty object

* enable strict null checks

* v3.0.2-rc.5

* fix getTestAssignments

* fix test

* ??

Author: leoromanovsky

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@eppo/js-client-sdk",
-  "version": "3.0.2-rc.1",
+  "version": "3.0.2-rc.5",
   "description": "Eppo SDK for client-side JavaScript applications",
   "main": "dist/index.js",
   "files": [
@@ -61,4 +61,4 @@
     "@eppo/js-client-sdk-common": "3.0.8",
     "md5": "^2.3.0"
   }
-}
+}

src/chrome.configuration-store.spec.ts

@@ -37,13 +37,13 @@ describe('ChromeStore', () => {
     expect(await chromeStore.isExpired()).toBe(true);
   });
 
-  it('should return null when no entries are found', async () => {
+  it('should return empty object when no entries are found', async () => {
     (extendedStorageLocal.get as jest.Mock).mockImplementation(() => {
       return Promise.resolve({});
     });
 
     const entries = await chromeStore.getEntries();
-    expect(entries).toBeNull();
+    expect(entries).toEqual({});
   });
 
   it('should be initialized after setting entries', async () => {

src/chrome.configuration-store.ts

@@ -14,12 +14,12 @@ export class ChromeStorageAsyncStore<T> implements IAsyncStore<T> {
     return Promise.resolve(true);
   }
 
-  public async getEntries(): Promise<Record<string, T> | null> {
+  public async getEntries(): Promise<Record<string, T>> {
     const configuration = await this.storageArea.get(this.chromeStorageKey);
     if (configuration?.[this.chromeStorageKey]) {
       return Promise.resolve(JSON.parse(configuration[this.chromeStorageKey]));
     }
-    return Promise.resolve(null);
+    return Promise.resolve({});
   }
 
   public async setEntries(entries: Record<string, T>): Promise<void> {

src/configuration-factory.ts

@@ -31,13 +31,13 @@ export function configurationStorageFactory(
     return new MemoryOnlyConfigurationStore();
   } else if (persistentStore) {
     return new HybridConfigurationStore(new MemoryStore<Flag>(), persistentStore);
-  } else if (hasChromeStorage) {
+  } else if (hasChromeStorage && chromeStorage) {
     // Chrome storage is available, use it as a fallback
     return new HybridConfigurationStore(
       new MemoryStore<Flag>(),
       new ChromeStorageAsyncStore<Flag>(chromeStorage),
     );
-  } else if (hasWindowLocalStorage) {
+  } else if (hasWindowLocalStorage && windowLocalStorage) {
     // window.localStorage is available, use it as a fallback
     return new HybridConfigurationStore(
       new MemoryStore<Flag>(),

src/index.ts

@@ -180,10 +180,11 @@ export async function init(config: IClientConfig): Promise<IEppoClient> {
         hasWindowLocalStorage: hasWindowLocalStorage(),
       },
       {
-        chromeStorage: hasChromeStorage() && chrome.storage.local,
-        windowLocalStorage: hasWindowLocalStorage() && window.localStorage,
+        chromeStorage: hasChromeStorage() ? chrome.storage.local : undefined,
+        windowLocalStorage: hasWindowLocalStorage() ? window.localStorage : undefined,
       },
     );
+    await configurationStore.init();
     EppoJSClient.instance.setConfigurationStore(configurationStore);
 
     const requestConfiguration: FlagConfigurationRequestParameters = {

src/local-storage-assignment-cache.ts

@@ -13,12 +13,12 @@ class LocalStorageAssignmentShim {
     return this.getCache().has(key);
   }
 
-  public get(key: string): string {
+  public get(key: string): string | undefined {
     if (!hasWindowLocalStorage()) {
-      return null;
+      return undefined;
     }
 
-    return this.getCache().get(key);
+    return this.getCache().get(key) ?? undefined;
   }
 
   public set(key: string, value: string) {

src/local-storage.spec.ts

@@ -22,8 +22,8 @@ describe('EppoLocalStorage', () => {
   });
 
   describe('get and set', () => {
-    it('returns null if entry is not present', async () => {
-      expect(await storage.getEntries()).toEqual(null);
+    it('returns empty object if entry is not present', async () => {
+      expect(await storage.getEntries()).toEqual({});
     });
 
     it('returns stored entries', async () => {

src/local-storage.ts

@@ -22,10 +22,10 @@ export class LocalStorageBackedAsyncStore<T> implements IAsyncStore<T> {
     return Promise.resolve(true);
   }
 
-  getEntries(): Promise<Record<string, T> | null> {
+  getEntries(): Promise<Record<string, T>> {
     const configuration = this.localStorage.getItem(this.localStorageKey);
     if (!configuration) {
-      return Promise.resolve(null);
+      return Promise.resolve({});
     }
     return Promise.resolve(JSON.parse(configuration));
   }

test/testHelpers.ts

@@ -52,16 +52,17 @@ export function getTestAssignments(
 ): { subject: SubjectTestCase; assignment: string | boolean | number | object }[] {
   const assignments: {
     subject: SubjectTestCase;
-    assignment: string | boolean | number | null | object;
+    assignment: string | boolean | number | object;
   }[] = [];
   for (const subject of testCase.subjects) {
-    const assignment = assignmentFn(
-      testCase.flag,
-      subject.subjectKey,
-      subject.subjectAttributes,
-      testCase.defaultValue,
-      obfuscated,
-    );
+    const assignment =
+      assignmentFn(
+        testCase.flag,
+        subject.subjectKey,
+        subject.subjectAttributes,
+        testCase.defaultValue,
+        obfuscated,
+      ) || testCase.defaultValue; // Fallback to defaultValue if null
     assignments.push({ subject: subject, assignment: assignment });
   }
   return assignments;

tsconfig.json

@@ -8,12 +8,15 @@
     "target": "es2017",
     "outDir": "dist",
     "noImplicitAny": true,
+    "strictNullChecks": true
   },
-  "include": ["src/**/*.ts"],
+  "include": [
+    "src/**/*.ts"
+  ],
   "exclude": [
     "node_modules",
     "dist",
     "src/**/*.spec.ts",
     "test/**/*"
   ]
-}
+}