SQS trigger script with preprocessor template

/**

 * General Trigger Preprocessor

 *

 * ⚠️ This function runs BEFORE the main function.

 *

 * It processes raw trigger data (e.g., MQTT, HTTP, SQS) before passing it to main().

 * Common tasks:

 * - Convert binary payloads to string/JSON

 * - Extract metadata

 * - Filter messages

 * - Add timestamps/context

 *

 * The returned object determines main() parameters:

 * - {a: 1, b: 2} → main(a, b)

 * - {msg} → main(msg)

 *

 * @param wm_trigger - Trigger details (e.g., MQTT, HTTP, SQS)

 * @param msg - Raw trigger data (format varies by trigger type)

 * @returns Processed data for main()

 */

export async function preprocessor(

  wm_trigger: {

    kind: 'http' | 'email' | 'webhook' | 'websocket' | 'kafka' | 'nats' | 'postgres' | 'sqs' | 'mqtt',

    sqs?: {

      queue_url: string,

      message_id?: string,

      receipt_handle?: string,

      attributes: Record<string, string>,

      message_attributes?: Record<string, {

        string_value?: string,

        data_type: string

      }>

    }

  },

  msg: string

) {

  if (wm_trigger.kind === 'sqs' && wm_trigger.sqs) {

    return {

      queueUrl: wm_trigger.sqs.queue_url,

      messageId: wm_trigger.sqs.message_id,

      receiptHandle: wm_trigger.sqs.receipt_handle,

      attributes: wm_trigger.sqs.attributes,

      messageAttributes: wm_trigger.sqs.message_attributes,

      msg

    };

  }

  throw new Error(`Expected sqs trigger kind, got: ${wm_trigger.kind}`);

}

/**

 * Main Function - Handles processed trigger events

 *

 * ⚠️ Called AFTER preprocessor(), with its return values.

 *

 * @param queueUrl - URL of the SQS queue

 * @param messageId - Unique message identifier (if available)

 * @param receiptHandle - Receipt handle for message deletion (if available)

 * @param attributes - Message attributes from SQS

 * @param messageAttributes - Custom message attributes (if any)

 * @param msg - Raw message content

 */

export async function main(

  queueUrl: string,

  messageId: string | undefined,

  receiptHandle: string | undefined,

  attributes: Record<string, string>,

  messageAttributes: Record<string, { string_value?: string; data_type: string }> | undefined,

  msg: string

) {

  // Implement the main function logic here

}