Function makeIdempotent

Example

// this is your processing function with an example record { transactionId: '123', foo: 'bar' }
const processRecord = (record: Record<string, unknown>): any => {
  // you custom processing logic
  return result;
};

// we use wrapper to make processing function idempotent with DynamoDBPersistenceLayer
const processIdempotently = makeIdempotent(processRecord, {
  persistenceStore: new DynamoDBPersistenceLayer()
  dataKeywordArgument: 'transactionId', // keyword argument to hash the payload and the result
});

export const handler = async (
  _event: EventRecords,
  _context: Context
): Promise<void> => {
  for (const record of _event.records) {
    const result = await processIdempotently(record);
    // do something with the result
  }

  return Promise.resolve();
};

@param fn - the function to make idempotent
@param options - the options to configure the idempotency behavior
Copy