docs(batch): review API docs & README

docs/utilities/batch.md

@@ -113,11 +113,11 @@ Processing batches from SQS works in three stages:
 
 === "index.ts"
 
-    ```typescript hl_lines="1-5 14 17 29-31"
+    ```typescript hl_lines="1-5 9 12 21-23"
     --8<--
-     examples/snippets/batch/gettingStartedSQS.ts::16
-     examples/snippets/batch/gettingStartedSQS.ts:18:29
-     examples/snippets/batch/gettingStartedSQS.ts:31:34
+     examples/snippets/batch/gettingStartedSQS.ts::11
+     examples/snippets/batch/gettingStartedSQS.ts:13:21
+     examples/snippets/batch/gettingStartedSQS.ts:23:25
     --8<--
     ```
 
@@ -144,7 +144,7 @@ Processing batches from SQS works in three stages:
 When using [SQS FIFO queues](https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/FIFO-queues.html){target="_blank"}, we will stop processing messages after the first failure, and return all failed and unprocessed messages in `batchItemFailures`.
 This helps preserve the ordering of messages in your queue.
 
-```typescript hl_lines="1-4 13 28-30"
+```typescript hl_lines="1-4 8 20-22"
 --8<-- "examples/snippets/batch/gettingStartedSQSFifo.ts"
 ```
 
@@ -167,11 +167,11 @@ Processing batches from Kinesis works in three stages:
 
 === "index.ts"
 
-    ```typescript hl_lines="1-5 14 17 27-29"
+    ```typescript hl_lines="1-5 9 12 19-21"
     --8<-- "examples/snippets/batch/gettingStartedKinesis.ts"
     ```
 
-    1.  **Step 1**. Creates a partial failure batch processor for Kinesis Data Streams. See [partial failure mechanics for details](#partial-failure-mechanics)
+    1.  Creates a partial failure batch processor for Kinesis Data Streams. See [partial failure mechanics for details](#partial-failure-mechanics)
 
 === "Sample response"
 
@@ -200,11 +200,11 @@ Processing batches from DynamoDB Streams works in three stages:
 
 === "index.ts"
 
-    ```typescript hl_lines="1-5 14 17 32-34"
+    ```typescript hl_lines="1-5 9 12 24-26"
     --8<-- "examples/snippets/batch/gettingStartedDynamoDBStreams.ts"
     ```
 
-    1.  **Step 1**. Creates a partial failure batch processor for DynamoDB Streams. See [partial failure mechanics for details](#partial-failure-mechanics)
+    1.  Creates a partial failure batch processor for DynamoDB Streams. See [partial failure mechanics for details](#partial-failure-mechanics)
 
 === "Sample response"
 
@@ -226,17 +226,17 @@ By default, we catch any exception raised by your record handler function. This
 
 === "Sample error handling with custom exception"
 
-    ```typescript hl_lines="30"
+    ```typescript hl_lines="25"
     --8<--
-     examples/snippets/batch/gettingStartedErrorHandling.ts::29
-     examples/snippets/batch/gettingStartedErrorHandling.ts:31:38
-     examples/snippets/batch/gettingStartedErrorHandling.ts:40:43
+     examples/snippets/batch/gettingStartedErrorHandling.ts::24
+     examples/snippets/batch/gettingStartedErrorHandling.ts:26:30
+     examples/snippets/batch/gettingStartedErrorHandling.ts:32:
     --8<--
     ```
 
     1. Any exception works here. See [extending BatchProcessorSync section, if you want to override this behavior.](#extending-batchprocessor)
 
-    2. Exceptions raised in `record_handler` will propagate to `process_partial_response`. <br/><br/> We catch them and include each failed batch item identifier in the response dictionary (see `Sample response` tab).
+    2. Exceptions raised in `recordHandler` will propagate to `process_partial_response`. <br/><br/> We catch them and include each failed batch item identifier in the response dictionary (see `Sample response` tab).
 
 === "Sample response"
 
@@ -397,7 +397,7 @@ Use the `BatchProcessor` directly in your function to access a list of all retur
 * **When successful**. We will include a tuple with `success`, the result of `recordHandler`, and the batch record
 * **When failed**. We will include a tuple with `fail`, exception as a string, and the batch record
 
-```typescript hl_lines="25 27-28 30-33 38" title="Accessing processed messages"
+```typescript hl_lines="17 19-20 23 28" title="Accessing processed messages"
 --8<-- "examples/snippets/batch/accessProcessedMessages.ts"
 ```
 
@@ -410,7 +410,7 @@ Within your `recordHandler` function, you might need access to the Lambda contex
 
 We can automatically inject the [Lambda context](https://docs.aws.amazon.com/lambda/latest/dg/typescript-context.html){target="_blank"} into your `recordHandler` as optional second argument if you register it when using `BatchProcessorSync` or the `processPartialResponseSync` function.
 
-```typescript hl_lines="17 35"
+```typescript hl_lines="12 27"
 --8<-- "examples/snippets/batch/accessLambdaContext.ts"
 ```
 
@@ -425,7 +425,7 @@ For these scenarios, you can subclass `BatchProcessor` and quickly override `suc
 
 Let's suppose you'd like to add a metric named `BatchRecordFailures` for each batch record that failed processing
 
-```typescript hl_lines="3 20 24 31 37" title="Extending failure handling mechanism in BatchProcessor"
+```typescript hl_lines="3 15 19 26 32" title="Extending failure handling mechanism in BatchProcessor"
 --8<-- "examples/snippets/batch/extendingFailure.ts"
 ```
 

examples/snippets/batch/accessLambdaContext.ts

@@ -4,12 +4,7 @@ import {
   processPartialResponse,
 } from '@aws-lambda-powertools/batch';
 import { Logger } from '@aws-lambda-powertools/logger';
-import type {
-  SQSEvent,
-  SQSRecord,
-  Context,
-  SQSBatchResponse,
-} from 'aws-lambda';
+import type { SQSRecord, Context, SQSHandler } from 'aws-lambda';
 
 const processor = new BatchProcessor(EventType.SQS);
 const logger = new Logger();
@@ -27,11 +22,7 @@ const recordHandler = (record: SQSRecord, lambdaContext?: Context): void => {
   }
 };
 
-export const handler = async (
-  event: SQSEvent,
-  context: Context
-): Promise<SQSBatchResponse> => {
-  return processPartialResponse(event, recordHandler, processor, {
+export const handler: SQSHandler = async (event, context) =>
+  processPartialResponse(event, recordHandler, processor, {
     context,
   });
-};

examples/snippets/batch/accessProcessedMessages.ts

@@ -1,11 +1,6 @@
 import { BatchProcessor, EventType } from '@aws-lambda-powertools/batch';
 import { Logger } from '@aws-lambda-powertools/logger';
-import type {
-  SQSEvent,
-  SQSRecord,
-  Context,
-  SQSBatchResponse,
-} from 'aws-lambda';
+import type { SQSRecord, SQSHandler } from 'aws-lambda';
 
 const processor = new BatchProcessor(EventType.SQS);
 const logger = new Logger();
@@ -18,19 +13,14 @@ const recordHandler = (record: SQSRecord): void => {
   }
 };
 
-export const handler = async (
-  event: SQSEvent,
-  context: Context
-): Promise<SQSBatchResponse> => {
+export const handler: SQSHandler = async (event, context) => {
   const batch = event.Records; // (1)!
 
   processor.register(batch, recordHandler, { context }); // (2)!
   const processedMessages = await processor.process();
 
   for (const message of processedMessages) {
-    const status: 'success' | 'fail' = message[0];
-    const error = message[1];
-    const record = message[2];
+    const [status, error, record] = message;
 
     logger.info('Processed record', { status, record, error });
   }

examples/snippets/batch/advancedTracingRecordHandler.ts

@@ -6,12 +6,7 @@ import {
 import { Tracer } from '@aws-lambda-powertools/tracer';
 import { captureLambdaHandler } from '@aws-lambda-powertools/tracer/middleware';
 import middy from '@middy/core';
-import type {
-  SQSEvent,
-  SQSRecord,
-  Context,
-  SQSBatchResponse,
-} from 'aws-lambda';
+import type { SQSRecord, SQSHandler, SQSEvent } from 'aws-lambda';
 
 const processor = new BatchProcessor(EventType.SQS);
 const tracer = new Tracer({ serviceName: 'serverlessAirline' });
@@ -35,10 +30,8 @@ const recordHandler = async (record: SQSRecord): Promise<void> => {
   subsegment?.close(); // (3)!
 };
 
-export const handler = middy(
-  async (event: SQSEvent, context: Context): Promise<SQSBatchResponse> => {
-    return processPartialResponse(event, recordHandler, processor, {
-      context,
-    });
-  }
+export const handler: SQSHandler = middy(async (event: SQSEvent, context) =>
+  processPartialResponse(event, recordHandler, processor, {
+    context,
+  })
 ).use(captureLambdaHandler(tracer));

examples/snippets/batch/customPartialProcessor.ts

@@ -14,7 +14,7 @@ import type {
   FailureResponse,
   BaseRecord,
 } from '@aws-lambda-powertools/batch/types';
-import type { SQSEvent, Context, SQSBatchResponse } from 'aws-lambda';
+import type { SQSHandler } from 'aws-lambda';
 
 const tableName = process.env.TABLE_NAME || 'table-not-found';
 
@@ -89,11 +89,7 @@ const recordHandler = (): number => {
   return Math.floor(randomInt(1, 10));
 };
 
-export const handler = async (
-  event: SQSEvent,
-  context: Context
-): Promise<SQSBatchResponse> => {
-  return processPartialResponse(event, recordHandler, processor, {
+export const handler: SQSHandler = async (event, context) =>
+  processPartialResponse(event, recordHandler, processor, {
     context,
   });
-};

examples/snippets/batch/extendingFailure.ts

@@ -9,12 +9,7 @@ import type {
   EventSourceDataClassTypes,
 } from '@aws-lambda-powertools/batch/types';
 import { Logger } from '@aws-lambda-powertools/logger';
-import type {
-  SQSEvent,
-  SQSRecord,
-  Context,
-  SQSBatchResponse,
-} from 'aws-lambda';
+import type { SQSRecord, SQSHandler } from 'aws-lambda';
 
 class MyProcessor extends BatchProcessor {
   #metrics: Metrics;
@@ -45,11 +40,7 @@ const recordHandler = (record: SQSRecord): void => {
   }
 };
 
-export const handler = async (
-  event: SQSEvent,
-  context: Context
-): Promise<SQSBatchResponse> => {
-  return processPartialResponse(event, recordHandler, processor, {
+export const handler: SQSHandler = async (event, context) =>
+  processPartialResponse(event, recordHandler, processor, {
     context,
   });
-};

examples/snippets/batch/gettingStartedDynamoDBStreams.ts

@@ -4,12 +4,7 @@ import {
   processPartialResponse,
 } from '@aws-lambda-powertools/batch';
 import { Logger } from '@aws-lambda-powertools/logger';
-import type {
-  DynamoDBStreamEvent,
-  DynamoDBRecord,
-  Context,
-  DynamoDBBatchResponse,
-} from 'aws-lambda';
+import type { DynamoDBRecord, DynamoDBStreamHandler } from 'aws-lambda';
 
 const processor = new BatchProcessor(EventType.DynamoDBStreams); // (1)!
 const logger = new Logger();
@@ -25,11 +20,7 @@ const recordHandler = async (record: DynamoDBRecord): Promise<void> => {
   }
 };
 
-export const handler = async (
-  event: DynamoDBStreamEvent,
-  context: Context
-): Promise<DynamoDBBatchResponse> => {
-  return processPartialResponse(event, recordHandler, processor, {
+export const handler: DynamoDBStreamHandler = async (event, context) =>
+  processPartialResponse(event, recordHandler, processor, {
     context,
   });
-};

examples/snippets/batch/gettingStartedErrorHandling.ts

@@ -4,12 +4,7 @@ import {
   processPartialResponse,
 } from '@aws-lambda-powertools/batch';
 import { Logger } from '@aws-lambda-powertools/logger';
-import type {
-  SQSEvent,
-  SQSRecord,
-  Context,
-  SQSBatchResponse,
-} from 'aws-lambda';
+import type { SQSRecord, SQSHandler } from 'aws-lambda';
 
 const processor = new BatchProcessor(EventType.SQS);
 const logger = new Logger();
@@ -32,12 +27,8 @@ const recordHandler = async (record: SQSRecord): Promise<void> => {
   }
 };
 
-export const handler = async (
-  event: SQSEvent,
-  context: Context
-): Promise<SQSBatchResponse> => {
+export const handler: SQSHandler = async (event, context) =>
   // prettier-ignore
-  return processPartialResponse(event, recordHandler, processor, { // (2)!
+  processPartialResponse(event, recordHandler, processor, { // (2)!
     context,
   });
-};

examples/snippets/batch/gettingStartedKinesis.ts

@@ -4,12 +4,7 @@ import {
   processPartialResponse,
 } from '@aws-lambda-powertools/batch';
 import { Logger } from '@aws-lambda-powertools/logger';
-import type {
-  KinesisStreamEvent,
-  KinesisStreamRecord,
-  Context,
-  KinesisStreamBatchResponse,
-} from 'aws-lambda';
+import type { KinesisStreamHandler, KinesisStreamRecord } from 'aws-lambda';
 
 const processor = new BatchProcessor(EventType.KinesisDataStreams); // (1)!
 const logger = new Logger();
@@ -20,11 +15,7 @@ const recordHandler = async (record: KinesisStreamRecord): Promise<void> => {
   logger.info('Processed item', { item: payload });
 };
 
-export const handler = async (
-  event: KinesisStreamEvent,
-  context: Context
-): Promise<KinesisStreamBatchResponse> => {
-  return processPartialResponse(event, recordHandler, processor, {
+export const handler: KinesisStreamHandler = async (event, context) =>
+  processPartialResponse(event, recordHandler, processor, {
     context,
   });
-};

examples/snippets/batch/gettingStartedSQS.ts

@@ -4,12 +4,7 @@ import {
   processPartialResponse,
 } from '@aws-lambda-powertools/batch';
 import { Logger } from '@aws-lambda-powertools/logger';
-import type {
-  SQSEvent,
-  SQSRecord,
-  Context,
-  SQSBatchResponse,
-} from 'aws-lambda';
+import type { SQSRecord, SQSHandler } from 'aws-lambda';
 
 const processor = new BatchProcessor(EventType.SQS); // (1)!
 const logger = new Logger();
@@ -23,13 +18,10 @@ const recordHandler = async (record: SQSRecord): Promise<void> => { // (2)!
   }
 };
 
-export const handler = async (
-  event: SQSEvent,
-  context: Context
-): Promise<SQSBatchResponse> => {
+export const handler: SQSHandler = async (event, context) =>
   // prettier-ignore
-  return processPartialResponse(event, recordHandler, processor, { // (3)!
+  processPartialResponse(event, recordHandler, processor, { // (3)!
     context,
   });
-};
+
 export { processor };

examples/snippets/batch/gettingStartedSQSFifo.ts

@@ -3,12 +3,7 @@ import {
   processPartialResponseSync,
 } from '@aws-lambda-powertools/batch';
 import { Logger } from '@aws-lambda-powertools/logger';
-import type {
-  SQSEvent,
-  SQSRecord,
-  Context,
-  SQSBatchResponse,
-} from 'aws-lambda';
+import type { SQSHandler, SQSRecord } from 'aws-lambda';
 
 const processor = new SqsFifoPartialProcessor(); // (1)!
 const logger = new Logger();
@@ -21,11 +16,7 @@ const recordHandler = (record: SQSRecord): void => {
   }
 };
 
-export const handler = async (
-  event: SQSEvent,
-  context: Context
-): Promise<SQSBatchResponse> => {
-  return processPartialResponseSync(event, recordHandler, processor, {
+export const handler: SQSHandler = async (event, context) =>
+  processPartialResponseSync(event, recordHandler, processor, {
     context,
   });
-};

examples/snippets/batch/testingYourCode.ts

@@ -36,7 +36,7 @@ describe('Function tests', () => {
     };
 
     // Act
-    const response = await handler(sqsEvent, context);
+    const response = await handler(sqsEvent, context, () => {});
 
     // Assess
     expect(response).toEqual(expectedResponse);