CD
Cloudflare Developers•4w ago
Json 🧈

How to correctly type the batch?

async queue(batch: MessageBatch<{ bucket: string }>, env): Promise<void> {
        // A queue consumer can make requests to other endpoints on the Internet,
        // write to R2 object storage, query a D1 Database, and much more.
        for (let message of batch.messages) {
            const { body } = message;

            const bucket = body.bucket;

            // Process each message (we'll just log these)
            console.log('Received queue', batch.queue);
            console.log('Received messages', batch.messages);

            console.log(`message ${message.id} processed: ${JSON.stringify(message.body)}`);
        }
    },
async queue(batch: MessageBatch<{ bucket: string }>, env): Promise<void> {
        // A queue consumer can make requests to other endpoints on the Internet,
        // write to R2 object storage, query a D1 Database, and much more.
        for (let message of batch.messages) {
            const { body } = message;

            const bucket = body.bucket;

            // Process each message (we'll just log these)
            console.log('Received queue', batch.queue);
            console.log('Received messages', batch.messages);

            console.log(`message ${message.id} processed: ${JSON.stringify(message.body)}`);
        }
    },
For whatever reason, batch is typed as MessageBatch<Error>. Do I have to configure this type myself, it would be nice if Workers had defined types for different event notifications. I only expect queue messages that come from created object notifications out of R2, so maybe this type should exist for ease of use. I also can't find where in the docs this topic is explored.
1 Reply
Json 🧈
Json 🧈OP•4w ago
I can explicitly specify the type by modifying the use of satisfies, but this is not ideal since they type isn't generate by wrangler. 
satisfies ExportedHandler<Env,
  {
    account: string;
    bucket: string;
    eventTime: string;
    action: string;
    object: {
      key: string;
      eTag: string;
      size: number;
    };
  }
>
satisfies ExportedHandler<Env,
  {
    account: string;
    bucket: string;
    eventTime: string;
    action: string;
    object: {
      key: string;
      eTag: string;
      size: number;
    };
  }
>

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