remove singleton for ddb client, add useragent in constructor

Author: Alexander Melnyk

packages/idempotency/src/persistence/DynamoDBPersistenceLayer.ts

@@ -2,21 +2,22 @@ import {
   IdempotencyItemAlreadyExistsError,
   IdempotencyItemNotFoundError,
 } from '../errors';
-import { IdempotencyRecordStatus } from '../types';
 import type { DynamoPersistenceOptions } from '../types';
+import { IdempotencyRecordStatus } from '../types';
 import {
+  AttributeValue,
+  DeleteItemCommand,
   DynamoDBClient,
   DynamoDBClientConfig,
   DynamoDBServiceException,
-  DeleteItemCommand,
   GetItemCommand,
   PutItemCommand,
   UpdateItemCommand,
-  AttributeValue,
 } from '@aws-sdk/client-dynamodb';
 import { marshall, unmarshall } from '@aws-sdk/util-dynamodb';
 import { IdempotencyRecord } from './IdempotencyRecord';
 import { BasePersistenceLayer } from './BasePersistenceLayer';
+import { addUserAgentMiddleware } from '@aws-lambda-powertools/commons';
 
 /**
  * DynamoDB persistence layer for idempotency records. This class will use the AWS SDK V3 to write and read idempotency records from DynamoDB.
@@ -28,7 +29,7 @@ import { BasePersistenceLayer } from './BasePersistenceLayer';
  * @implements {BasePersistenceLayer}
  */
 class DynamoDBPersistenceLayer extends BasePersistenceLayer {
-  private client?: DynamoDBClient;
+  private client!: DynamoDBClient;
   private clientConfig: DynamoDBClientConfig = {};
   private dataAttr: string;
   private expiryAttr: string;
@@ -64,18 +65,18 @@ class DynamoDBPersistenceLayer extends BasePersistenceLayer {
       if (config?.awsSdkV3Client instanceof DynamoDBClient) {
         this.client = config.awsSdkV3Client;
       } else {
-        console.warn(
-          'Invalid AWS SDK V3 client passed to DynamoDBPersistenceLayer. Using default client.'
-        );
+        throw Error('Not valid DynamoDBClient provided.');
       }
     } else {
       this.clientConfig = config?.clientConfig ?? {};
+      this.client = new DynamoDBClient(this.clientConfig);
     }
+
+    addUserAgentMiddleware(this.client, 'idempotency');
   }
 
   protected async _deleteRecord(record: IdempotencyRecord): Promise<void> {
-    const client = this.getClient();
-    await client.send(
+    await this.client.send(
       new DeleteItemCommand({
         TableName: this.tableName,
         Key: this.getKey(record.idempotencyKey),
@@ -86,8 +87,7 @@ class DynamoDBPersistenceLayer extends BasePersistenceLayer {
   protected async _getRecord(
     idempotencyKey: string
   ): Promise<IdempotencyRecord> {
-    const client = this.getClient();
-    const result = await client.send(
+    const result = await this.client.send(
       new GetItemCommand({
         TableName: this.tableName,
         Key: this.getKey(idempotencyKey),
@@ -111,8 +111,6 @@ class DynamoDBPersistenceLayer extends BasePersistenceLayer {
   }
 
   protected async _putRecord(record: IdempotencyRecord): Promise<void> {
-    const client = this.getClient();
-
     const item = {
       ...this.getKey(record.idempotencyKey),
       ...marshall({
@@ -163,7 +161,7 @@ class DynamoDBPersistenceLayer extends BasePersistenceLayer {
       ].join(' OR ');
 
       const now = Date.now();
-      await client.send(
+      await this.client.send(
         new PutItemCommand({
           TableName: this.tableName,
           Item: item,
@@ -195,8 +193,6 @@ class DynamoDBPersistenceLayer extends BasePersistenceLayer {
   }
 
   protected async _updateRecord(record: IdempotencyRecord): Promise<void> {
-    const client = this.getClient();
-
     const updateExpressionFields: string[] = [
       '#response_data = :response_data',
       '#expiry = :expiry',
@@ -219,7 +215,7 @@ class DynamoDBPersistenceLayer extends BasePersistenceLayer {
       expressionAttributeValues[':validation_key'] = record.payloadHash;
     }
 
-    await client.send(
+    await this.client.send(
       new UpdateItemCommand({
         TableName: this.tableName,
         Key: this.getKey(record.idempotencyKey),
@@ -230,14 +226,6 @@ class DynamoDBPersistenceLayer extends BasePersistenceLayer {
     );
   }
 
-  private getClient(): DynamoDBClient {
-    if (!this.client) {
-      this.client = new DynamoDBClient(this.clientConfig);
-    }
-
-    return this.client;
-  }
-
   /**
    * Build primary key attribute simple or composite based on params.
    *

packages/idempotency/tests/unit/persistence/DynamoDbPersistenceLayer.test.ts

@@ -163,20 +163,14 @@ describe('Class: DynamoDBPersistenceLayer', () => {
       );
     });
 
-    test('when passed an invalid AWS SDK client it logs a warning', () => {
-      // Prepare
-      const consoleWarnSpy = jest.spyOn(console, 'warn').mockImplementation();
-
-      // Act
-      new TestDynamoDBPersistenceLayer({
-        tableName: dummyTableName,
-        awsSdkV3Client: {} as DynamoDBClient,
-      });
-
-      // Assess
-      expect(consoleWarnSpy).toHaveBeenCalledWith(
-        'Invalid AWS SDK V3 client passed to DynamoDBPersistenceLayer. Using default client.'
-      );
+    test('when passed an invalid AWS SDK client, it throws an error', () => {
+      // Act & Assess
+      expect(() => {
+        new TestDynamoDBPersistenceLayer({
+          tableName: dummyTableName,
+          awsSdkV3Client: {} as DynamoDBClient,
+        });
+      }).toThrow();
     });
 
     test('when passed a client config it stores it for later use', () => {