SQS Message Queue Adapter

DRY Castore MessageQueue definition using AWS SQS.

📥 Installation

# npm
npm install @castore/sqs-message-queue-adapter

# yarn
yarn add @castore/sqs-message-queue-adapter

This package has @castore/core and @aws-sdk/client-sqs (above v3) as peer dependencies, so you will have to install them as well:

# npm
npm install @castore/core @aws-sdk/client-sqs

# yarn
yarn add @castore/core @aws-sdk/client-sqs

👩‍💻 Usage

import { SQSClient } from '@aws-sdk/client-sqs';

import { SQSMessageQueueAdapter } from '@castore/sqs-message-queue-adapter';

const sqsClient = new SQSClient({});

const messageQueueAdapter = new SQSMessageQueueAdapter({
  queueUrl: 'https://sqs.us-east-1.amazonaws.com/111122223333/my-super-queue',
  sqsClient,
});

// 👇 Alternatively, provide a getter
const messageQueueAdapter = new SQSMessageQueueAdapter({
  queueUrl: () => process.env.MY_SQS_QUEUE_URL,
  sqsClient,
});

const appMessageQueue = new NotificationMessageQueue({
  ...
  messageQueueAdapter
})

This will directly plug your MessageQueue to SQS 🙌

If your queue is of type FIFO, don't forget to specify it in the constructor:

const messageQueueAdapter = new SQSMessageQueueAdapter({
  queueUrl: 'https://sqs.us-east-1.amazonaws.com/111122223333/my-super-queue',
  sqsClient,
  fifo: true,
});

🤔 How it works

When publishing a message, it is JSON stringified and passed as the record body.

// 👇 Aggregate exists
const message = {
  body: '{
    \"eventStoreId\": \"POKEMONS\",
    \"aggregateId\": \"123\",
  }',
  ... // <= Other technical SQS properties
}

// 👇 Notification
const message = {
  body: '{
    \"eventStoreId\": \"POKEMONS\",
    \"event\": {
      \"aggregateId\": \"123\",
      \"version\": 1,
      \"type\": \"POKEMON_APPEARED\",
      \"timestamp\": ...
      ...
    },
  }',
  ...
}

// 👇 State-carrying
const message = {
  body: '{
    \"eventStoreId\": \"POKEMONS\",
    \"event\": {
      \"aggregateId\": \"123\",
      ...
    },
    \"aggregate\": ...,
  }',
  ...
};

If your queue is of type FIFO, the messageGroupId and messageDeduplicationId will be derived from a combination of the eventStoreId, aggregateId and version:

// 👇 Fifo message
const message = {
  messageBody: ...,
  messageGroupId: "POKEMONS#123",
  messageDeduplicationId: "POKEMONS#123#1", // <= Or "POKEMONS#123" for AggregateExistsMessageQueues
  ... // <= Other technical SQS properties
};

If the replay option is set to true, a replay metadata attribute is included in the message:

// 👇 Replayed notification message
const message = {
  body:  '{
    \"eventStoreId\": \"POKEMONS\",
    \"event\": {
      \"aggregateId\": \"123\",
      ...
    },
  }',
  messageAttributes: {
    replay: {
      // 👇 boolean type is not available in SQS 🤷‍♂️
      dataType: 'Number',
      // 👇 numberValue is not available in SQS 🤷‍♂️
      stringValue: '1',
    },
  },
  ...
};

On the worker side, you can use the SQSMessageQueueMessage and SQSMessageQueueMessageBody TS types to type your argument:

import type {
  SQSMessageQueueMessage,
  SQSMessageQueueMessageBody,
} from '@castore/sqs-message-queue-adapter';

const appMessagesWorker = async ({ Records }: SQSMessageQueueMessage) => {
  Records.forEach(({ body }) => {
    // 👇 Correctly typed!
    const recordBody: SQSMessageQueueMessageBody<typeof appMessageQueue> =
      JSON.parse(body);
  });
};

🔑 IAM

The publishMessage method requires the sqs:SendMessage IAM permission on the provided SQS queue.