Fix: return response from callback

src/AsyncStore.ts

@@ -4,7 +4,7 @@ import AsyncStoreParams from './AsyncStoreParams';
  * Async Store implementation contract.
  */
 interface AsyncStore {
-  initialize: (callback: (err?: any) => void, params?: AsyncStoreParams) => void;
+  initialize: (callback: (err?: any) => void, params?: AsyncStoreParams) => any;
   set: (properties: any) => void;
   get: (key: string) => any;
   getAll: () => any;

src/impl/domain.ts

@@ -28,7 +28,7 @@ export function initialize(callback: (err?: any) => void, params?: AsyncStorePar
   d[STORE_KEY] = Object.create(null);
   d[ID_KEY] = randomUUID();
 
-  d.run(callback);
+  return d.run(callback);
 }
 
 /**

src/index.ts

@@ -99,7 +99,7 @@ export function initializeFastifyPlugin(adapter: AsyncStoreAdapter = AsyncStoreA
  * Initialize the async store based on the adapter provided.
  *
  * @param {AsyncStoreAdapter} [adapter=AsyncStoreAdapter.DOMAIN]
- * @returns {(params: AsyncStoreParams) => void}
+ * @returns {(callback: (err?: any) => void, params?: AsyncStoreParams) => any }
  */
 export function initialize(adapter: AsyncStoreAdapter = AsyncStoreAdapter.DOMAIN) {
   if (isInitialized()) {
@@ -111,7 +111,7 @@ export function initialize(adapter: AsyncStoreAdapter = AsyncStoreAdapter.DOMAIN
   return (callback: (err?: any) => void, params?: AsyncStoreParams) => {
     initializedAdapter = adapter;
 
-    instance.initialize(callback, params);
+    return instance.initialize(callback, params);
   };
 }
 

test/domain.test.ts

@@ -839,5 +839,88 @@ describe('store: [adapter=DOMAIN]', () => {
         globalStore.initialize(adapter)(callback);
       });
     });
+
+    it('should return the response from callback function.', (done) => {
+      const callback = () => {
+        globalStore.set({ foo: 'foo' });
+
+        return functionAccessingStore();
+      };
+
+      const functionAccessingStore = () => {
+        return globalStore.get('foo');
+      };
+
+      const response = globalStore.initialize(adapter)(callback);
+      expect(response).to.equal('foo');
+
+      done();
+    });
+
+    it('should return the response from async callback function.', async () => {
+      const callback = async () => {
+        globalStore.set({ foo: 'foo' });
+
+        functionAccessingStore();
+        const response = await asyncTask();
+
+        return response;
+      };
+
+      const functionAccessingStore = () => {
+        expect(globalStore.get('foo')).to.equal('foo');
+      };
+
+      const asyncTask = () => {
+        return new Promise((resolve) => {
+          setTimeout(() => {
+            resolve(globalStore.get('foo'));
+          }, 1);
+        });
+      };
+
+      const response = await globalStore.initialize(adapter)(callback);
+      expect(response).to.equal('foo');
+    });
+  });
+
+  describe('Error Handling:', () => {
+    it('should bubble up the promise rejection from the callback.', async () => {
+      const callback = () => {
+        globalStore.set({ foo: 'foo' });
+
+        return new Promise((resolve, reject) => {
+          setTimeout(() => {
+            reject('Hello world');
+          }, 1);
+        });
+      };
+
+      try {
+        await globalStore.initialize(adapter)(callback);
+        expect.fail('Should not reach here.');
+      } catch (e) {
+        expect(e).to.equal('Hello world');
+      }
+    });
+
+    it('should bubble up the error thrown from the callback.', (done) => {
+      const callback = () => {
+        globalStore.set({ foo: 'foo' });
+
+        throw new Error('Hello world');
+      };
+
+      try {
+        globalStore.initialize(adapter)(callback);
+        expect.fail('Should not reach here.');
+      } catch (e) {
+        if (e instanceof Error) {
+          expect(e.message).to.equal('Hello world');
+        }
+      }
+
+      done();
+    });
   });
 });