@vercel/blob: pagination with limit: N, N <1000

[gheorghemolnar]

I'm currently evaluating the @vercel/storage blob in my project and I came across this pottential issue while using list with pagination.

Context:

• I've set up the token
• a total of 6 files uploaded on my project storage
• using the list with limit of 2

Problem Description:

• i'm issuing the first request with no cursor

  • I get the first 2 results, with: 'cursor' populated with a string and 'hasMore': true

• on the 2nd request, I put the cursor and its previously received value, in query

  • I get the same first results il 'files', with 'cursor' populated with a different string and 'hasMore': true

The behaviour of the 2nd request is happening for the followings request:
- cursor populated every time with a differrent string value
- hasMore is polpulated with true, event if it should return hasMore: false (ex. on the 4th time call of the 'limit' function).

I can get all the results (6 of them), only if I don't specify the limit in the optional parameters of the limit function.
Can you give me some insights on this ?
Thank you !

[vvo]

Hey there @gheorghemolnar I just tested your setup and could not generate the same issues.

Here's my script:

import { list } from "@vercel/blob";

async function listFilesTwoByTwo() {
  let hasMore = true;
  let cursor;
  const limit = 2;

  while (hasMore) {
    const {
      blobs,
      cursor: newCursor,
      hasMore: newHasMore,
    } = await list({ limit, cursor });

    console.log(blobs.length, typeof newCursor, newHasMore);

    cursor = newCursor;
    hasMore = newHasMore;
  }
}

listFilesTwoByTwo();

And the result:

> BLOB_READ_WRITE_TOKEN="xxx" node test.js
2 string true # Good
2 string true
2 string true
2 string true
2 string true
2 string true
2 string true
2 string true
1 undefined false # Good

Can you confirm my script output is the one you would expect? And check why you're getting a different result, thanks!

[gheorghemolnar]

Hi @vvo , thank you for your quick response.
Indeed, I've tested the example, and it's working properly.

But in my case, i'm not using it in one loop, that gets all the results.

import { list } from "@vercel/blob";

let cursorPrevious = ""

async function listFilesTwoByTwo(cursor = "") {
    const limit = 2;
    const {
      blobs,
      cursor: newCursor,
      hasMore: newHasMore,
    } = await list({ limit, cursor });

    return {
        cursor:newCursor,
        hasMore:newHasMore
    }
}


listFilesTwoByTwo(cursorPrevious);            // here I get {cursor: 'new value 01', hasMore: true}
listFilesTwoByTwo(cursorPrevious);            // here I get {cursor: 'new value 02', hasMore: true}
... 
4th times
....
listFilesTwoByTwo(cursorPrevious);             // here I get {cursor: 'new value 0X', hasMore: true}     
                                                                    // I would expect hasMore: false, and maybe cursor: ""

Thank you again