improv(batch): improve errors (#1648)

* improv(batch): improve errors

* tests: updated tests with assertions

Author: dreamorosi

packages/batch/src/AsyncBatchProcessor.ts

@@ -1,4 +1,5 @@
 import { BasePartialBatchProcessor } from './BasePartialBatchProcessor';
+import { BatchProcessingError } from './errors';
 import type { BaseRecord, FailureResponse, SuccessResponse } from './types';
 
 /**
@@ -24,7 +25,9 @@ class AsyncBatchProcessor extends BasePartialBatchProcessor {
    * @returns response of success or failure
    */
   public processRecord(_record: BaseRecord): SuccessResponse | FailureResponse {
-    throw new Error('Not implemented. Use asyncProcess() instead.');
+    throw new BatchProcessingError(
+      'Not implemented. Use asyncProcess() instead.'
+    );
   }
 }
 

packages/batch/src/BasePartialBatchProcessor.ts

@@ -5,7 +5,7 @@ import type {
 } from 'aws-lambda';
 import { BasePartialProcessor } from './BasePartialProcessor';
 import { DATA_CLASS_MAPPING, DEFAULT_RESPONSE, EventType } from './constants';
-import { BatchProcessingError } from './errors';
+import { FullBatchFailureError } from './errors';
 import type {
   EventSourceDataClassTypes,
   PartialItemFailureResponse,
@@ -46,12 +46,7 @@ abstract class BasePartialBatchProcessor extends BasePartialProcessor {
     }
 
     if (this.entireBatchFailed()) {
-      throw new BatchProcessingError(
-        'All records failed processing. ' +
-          this.exceptions.length +
-          ' individual errors logged separately below.',
-        this.exceptions
-      );
+      throw new FullBatchFailureError(this.errors);
     }
 
     const messages: PartialItemFailures[] = this.getMessagesToReport();
@@ -110,7 +105,7 @@ abstract class BasePartialBatchProcessor extends BasePartialProcessor {
    * @returns true if all records resulted in exception results
    */
   public entireBatchFailed(): boolean {
-    return this.exceptions.length == this.records.length;
+    return this.errors.length == this.records.length;
   }
 
   /**
@@ -135,7 +130,7 @@ abstract class BasePartialBatchProcessor extends BasePartialProcessor {
   public prepare(): void {
     this.successMessages.length = 0;
     this.failureMessages.length = 0;
-    this.exceptions.length = 0;
+    this.errors.length = 0;
     this.batchResponse = DEFAULT_RESPONSE;
   }
 

packages/batch/src/BasePartialProcessor.ts

@@ -11,7 +11,7 @@ import type {
  * Abstract class for batch processors.
  */
 abstract class BasePartialProcessor {
-  public exceptions: Error[];
+  public errors: Error[];
 
   public failureMessages: EventSourceDataClassTypes[];
 
@@ -29,7 +29,7 @@ abstract class BasePartialProcessor {
   public constructor() {
     this.successMessages = [];
     this.failureMessages = [];
-    this.exceptions = [];
+    this.errors = [];
     this.records = [];
     this.handler = new Function();
   }
@@ -84,7 +84,7 @@ abstract class BasePartialProcessor {
     exception: Error
   ): FailureResponse {
     const entry: FailureResponse = ['fail', exception.message, record];
-    this.exceptions.push(exception);
+    this.errors.push(exception);
     this.failureMessages.push(record);
 
     return entry;

packages/batch/src/BatchProcessor.ts

@@ -1,4 +1,5 @@
 import { BasePartialBatchProcessor } from './BasePartialBatchProcessor';
+import { BatchProcessingError } from './errors';
 import type { BaseRecord, FailureResponse, SuccessResponse } from './types';
 
 /**
@@ -8,7 +9,7 @@ class BatchProcessor extends BasePartialBatchProcessor {
   public async asyncProcessRecord(
     _record: BaseRecord
   ): Promise<SuccessResponse | FailureResponse> {
-    throw new Error('Not implemented. Use process() instead.');
+    throw new BatchProcessingError('Not implemented. Use process() instead.');
   }
 
   /**

packages/batch/src/SqsFifoPartialProcessor.ts

@@ -1,5 +1,6 @@
 import { BatchProcessor } from './BatchProcessor';
 import { EventType } from './constants';
+import { SqsFifoShortCircuitError } from './errors';
 import type { FailureResponse, SuccessResponse } from './types';
 
 /**
@@ -52,10 +53,7 @@ class SqsFifoPartialProcessor extends BatchProcessor {
     for (const record of remainingRecords) {
       const data = this.toBatchType(record, this.eventType);
       processedRecords.push(
-        this.failureHandler(
-          data,
-          new Error('A previous record failed processing')
-        )
+        this.failureHandler(data, new SqsFifoShortCircuitError())
       );
     }
 

packages/batch/src/asyncProcessPartialResponse.ts

@@ -1,5 +1,5 @@
 import { BasePartialBatchProcessor } from './BasePartialBatchProcessor';
-import { EventType } from './constants';
+import { UnexpectedBatchTypeError } from './errors';
 import type {
   BaseRecord,
   BatchProcessingOptions,
@@ -19,13 +19,8 @@ const asyncProcessPartialResponse = async (
   processor: BasePartialBatchProcessor,
   options?: BatchProcessingOptions
 ): Promise<PartialItemFailureResponse> => {
-  if (!event.Records) {
-    const eventTypes: string = Object.values(EventType).toString();
-    throw new Error(
-      'Failed to convert event to record batch for processing.\nPlease ensure batch event is a valid ' +
-        eventTypes +
-        ' event.'
-    );
+  if (!event.Records || !Array.isArray(event.Records)) {
+    throw new UnexpectedBatchTypeError();
   }
 
   processor.register(event.Records, recordHandler, options);

packages/batch/src/errors.ts

@@ -1,49 +1,59 @@
+import { EventType } from './constants';
+
 /**
- * Base error type for batch processing
- * All errors thrown by major failures extend this base class
+ * Base error thrown by the Batch Processing utility
  */
-class BaseBatchProcessingError extends Error {
-  public childErrors: Error[];
-
-  public msg: string;
-
-  public constructor(msg: string, childErrors: Error[]) {
-    super(msg);
-    this.msg = msg;
-    this.childErrors = childErrors;
+class BatchProcessingError extends Error {
+  public constructor(message: string) {
+    super(message);
+    this.name = 'BatchProcessingError';
   }
+}
 
-  /**
-   * Generates a list of errors that were generated by the major failure
-   * @returns Formatted string listing all the errors that occurred
-   *
-   * @example
-   * When all batch records fail to be processed, this will generate a string like:
-   * All records failed processing. 3 individual errors logged separately below.
-   * ,Failed to process record.
-   * ,Failed to process record.
-   * ,Failed to process record.
-   */
-  public formatErrors(parentErrorString: string): string {
-    const errorList: string[] = [parentErrorString + '\n'];
-
-    for (const error of this.childErrors) {
-      errorList.push(error.message + '\n');
-    }
+/**
+ * Error thrown by the Batch Processing utility when all batch records failed to be processed
+ */
+class FullBatchFailureError extends BatchProcessingError {
+  public recordErrors: Error[];
 
-    return '\n' + errorList;
+  public constructor(childErrors: Error[]) {
+    super('All records failed processing. See individual errors below.');
+    this.recordErrors = childErrors;
+    this.name = 'FullBatchFailureError';
   }
 }
 
 /**
- * When all batch records failed to be processed
+ * Error thrown by the Batch Processing utility when a SQS FIFO queue is short-circuited.
+ * This happens when a record fails processing and the remaining records are not processed
+ * to avoid out-of-order delivery.
  */
-class BatchProcessingError extends BaseBatchProcessingError {
-  public constructor(msg: string, childErrors: Error[]) {
-    super(msg, childErrors);
-    const parentErrorString: string = this.message;
-    this.message = this.formatErrors(parentErrorString);
+class SqsFifoShortCircuitError extends BatchProcessingError {
+  public constructor() {
+    super(
+      'A previous record failed processing. The remaining records were not processed to avoid out-of-order delivery.'
+    );
+    this.name = 'SqsFifoShortCircuitError';
   }
 }
 
-export { BaseBatchProcessingError, BatchProcessingError };
+/**
+ * Error thrown by the Batch Processing utility when a partial processor receives an unexpected
+ * batch type.
+ */
+class UnexpectedBatchTypeError extends BatchProcessingError {
+  public constructor() {
+    super(
+      `Unexpected batch type. Possible values are: ${Object.values(
+        EventType
+      ).join(', ')}`
+    );
+    this.name = 'UnexpectedBatchTypeError';
+  }
+}
+export {
+  BatchProcessingError,
+  FullBatchFailureError,
+  SqsFifoShortCircuitError,
+  UnexpectedBatchTypeError,
+};

packages/batch/src/processPartialResponse.ts

@@ -1,5 +1,5 @@
 import { BasePartialBatchProcessor } from './BasePartialBatchProcessor';
-import { EventType } from './constants';
+import { UnexpectedBatchTypeError } from './errors';
 import type {
   BaseRecord,
   BatchProcessingOptions,
@@ -19,13 +19,8 @@ const processPartialResponse = (
   processor: BasePartialBatchProcessor,
   options?: BatchProcessingOptions
 ): PartialItemFailureResponse => {
-  if (!event.Records) {
-    const eventTypes: string = Object.values(EventType).toString();
-    throw new Error(
-      'Failed to convert event to record batch for processing.\nPlease ensure batch event is a valid ' +
-        eventTypes +
-        ' event.'
-    );
+  if (!event.Records || !Array.isArray(event.Records)) {
+    throw new UnexpectedBatchTypeError();
   }
 
   processor.register(event.Records, recordHandler, options);

packages/batch/tests/unit/AsyncBatchProcessor.test.ts

@@ -7,7 +7,7 @@ import type { Context } from 'aws-lambda';
 import { helloworldContext as dummyContext } from '../../../commons/src/samples/resources/contexts';
 import { AsyncBatchProcessor } from '../../src/AsyncBatchProcessor';
 import { EventType } from '../../src/constants';
-import { BatchProcessingError } from '../../src/errors';
+import { BatchProcessingError, FullBatchFailureError } from '../../src/errors';
 import type { BatchProcessingOptions } from '../../src/types';
 import {
   dynamodbRecordFactory,
@@ -95,7 +95,7 @@ describe('Class: AsyncBatchProcessor', () => {
 
       // Assess
       await expect(processor.asyncProcess()).rejects.toThrowError(
-        BatchProcessingError
+        FullBatchFailureError
       );
     });
   });
@@ -160,7 +160,7 @@ describe('Class: AsyncBatchProcessor', () => {
 
       // Assess
       await expect(processor.asyncProcess()).rejects.toThrowError(
-        BatchProcessingError
+        FullBatchFailureError
       );
     });
   });
@@ -225,7 +225,7 @@ describe('Class: AsyncBatchProcessor', () => {
 
       // Assess
       await expect(processor.asyncProcess()).rejects.toThrowError(
-        BatchProcessingError
+        FullBatchFailureError
       );
     });
   });
@@ -279,7 +279,7 @@ describe('Class: AsyncBatchProcessor', () => {
       // Act
       processor.register(records, asyncHandlerWithContext, badOptions);
       await expect(() => processor.asyncProcess()).rejects.toThrowError(
-        BatchProcessingError
+        FullBatchFailureError
       );
     });
   });
@@ -289,8 +289,6 @@ describe('Class: AsyncBatchProcessor', () => {
     const processor = new AsyncBatchProcessor(EventType.SQS);
 
     // Act & Assess
-    expect(() => processor.process()).toThrowError(
-      'Not implemented. Use asyncProcess() instead.'
-    );
+    expect(() => processor.process()).toThrowError(BatchProcessingError);
   });
 });

packages/batch/tests/unit/BatchProcessor.test.ts

@@ -7,7 +7,7 @@ import type { Context } from 'aws-lambda';
 import { helloworldContext as dummyContext } from '../../../commons/src/samples/resources/contexts';
 import { BatchProcessor } from '../../src/BatchProcessor';
 import { EventType } from '../../src/constants';
-import { BatchProcessingError } from '../../src/errors';
+import { BatchProcessingError, FullBatchFailureError } from '../../src/errors';
 import type { BatchProcessingOptions } from '../../src/types';
 import {
   dynamodbRecordFactory,
@@ -92,7 +92,7 @@ describe('Class: BatchProcessor', () => {
 
       // Act & Assess
       processor.register(records, sqsRecordHandler);
-      expect(() => processor.process()).toThrowError(BatchProcessingError);
+      expect(() => processor.process()).toThrowError(FullBatchFailureError);
     });
   });
 
@@ -154,7 +154,7 @@ describe('Class: BatchProcessor', () => {
       processor.register(records, kinesisRecordHandler);
 
       // Assess
-      expect(() => processor.process()).toThrowError(BatchProcessingError);
+      expect(() => processor.process()).toThrowError(FullBatchFailureError);
     });
   });
 
@@ -217,7 +217,7 @@ describe('Class: BatchProcessor', () => {
       processor.register(records, dynamodbRecordHandler);
 
       // Assess
-      expect(() => processor.process()).toThrowError(BatchProcessingError);
+      expect(() => processor.process()).toThrowError(FullBatchFailureError);
     });
   });
 
@@ -269,7 +269,7 @@ describe('Class: BatchProcessor', () => {
 
       // Act
       processor.register(records, handlerWithContext, badOptions);
-      expect(() => processor.process()).toThrowError(BatchProcessingError);
+      expect(() => processor.process()).toThrowError(FullBatchFailureError);
     });
   });
 
@@ -278,8 +278,8 @@ describe('Class: BatchProcessor', () => {
     const processor = new BatchProcessor(EventType.SQS);
 
     // Act & Assess
-    await expect(() => processor.asyncProcess()).rejects.toThrow(
-      'Not implemented. Use process() instead.'
+    await expect(() => processor.asyncProcess()).rejects.toThrowError(
+      BatchProcessingError
     );
   });
 });