fix: disable idempotency doesn't disable dynamodb client creation in persistent store (#796)

* do not create DynamoDbClient when idempotency is disabled

* ignoring case for idempotency disable env

Author: jeromevdl

powertools-idempotency/src/main/java/software/amazon/lambda/powertools/idempotency/internal/IdempotentAspect.java

@@ -47,7 +47,7 @@ public Object around(ProceedingJoinPoint pjp,
                          Idempotent idempotent) throws Throwable {
 
         String idempotencyDisabledEnv = System.getenv().get(Constants.IDEMPOTENCY_DISABLED_ENV);
-        if (idempotencyDisabledEnv != null && !idempotencyDisabledEnv.equals("false")) {
+        if (idempotencyDisabledEnv != null && !idempotencyDisabledEnv.equalsIgnoreCase("false")) {
             return pjp.proceed(pjp.getArgs());
         }
 

powertools-idempotency/src/main/java/software/amazon/lambda/powertools/idempotency/persistence/DynamoDBPersistenceStore.java

@@ -78,11 +78,18 @@ private DynamoDBPersistenceStore(String tableName,
         if (client != null) {
             this.dynamoDbClient = client;
         } else {
-            DynamoDbClientBuilder ddbBuilder = DynamoDbClient.builder()
-                    .credentialsProvider(EnvironmentVariableCredentialsProvider.create())
-                    .httpClient(UrlConnectionHttpClient.builder().build())
-                    .region(Region.of(System.getenv(AWS_REGION_ENV)));
-            this.dynamoDbClient = ddbBuilder.build();
+            String idempotencyDisabledEnv = System.getenv().get(Constants.IDEMPOTENCY_DISABLED_ENV);
+            if (idempotencyDisabledEnv == null || idempotencyDisabledEnv.equalsIgnoreCase("false")) {
+                DynamoDbClientBuilder ddbBuilder = DynamoDbClient.builder()
+                        .credentialsProvider(EnvironmentVariableCredentialsProvider.create())
+                        .httpClient(UrlConnectionHttpClient.builder().build())
+                        .region(Region.of(System.getenv(AWS_REGION_ENV)));
+                this.dynamoDbClient = ddbBuilder.build();
+            } else {
+                // we do not want to create a DynamoDbClient if idempotency is disabled
+                // null is ok as idempotency won't be called
+                this.dynamoDbClient = null;
+            }
         }
     }
 

powertools-idempotency/src/test/java/software/amazon/lambda/powertools/idempotency/persistence/DynamoDBPersistenceStoreTest.java

@@ -16,7 +16,9 @@
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.junitpioneer.jupiter.SetEnvironmentVariable;
 import software.amazon.awssdk.services.dynamodb.model.*;
+import software.amazon.lambda.powertools.idempotency.Constants;
 import software.amazon.lambda.powertools.idempotency.DynamoDBConfig;
 import software.amazon.lambda.powertools.idempotency.IdempotencyConfig;
 import software.amazon.lambda.powertools.idempotency.exceptions.IdempotencyItemAlreadyExistsException;
@@ -260,6 +262,13 @@ public void endToEndWithCustomAttrNamesAndSortKey() throws IdempotencyItemNotFou
         }
     }
 
+    @Test
+    @SetEnvironmentVariable(key = Constants.IDEMPOTENCY_DISABLED_ENV, value = "true")
+    public void idempotencyDisabled_noClientShouldBeCreated() {
+        DynamoDBPersistenceStore store = DynamoDBPersistenceStore.builder().withTableName(TABLE_NAME).build();
+        assertThatThrownBy(() -> store.getRecord("fake")).isInstanceOf(NullPointerException.class);
+    }
+
     @BeforeEach
     public void setup() {
         dynamoDBPersistenceStore = DynamoDBPersistenceStore.builder()