Converting BigInt to Bytes Issues

[rolandsaven]

So I'm having issues converting a BigInt to Bytes. What am I doing wrong?

let oneString = BigInt.fromString('1');
let one = BigInt.fromI32(1 as i32);

log.info("Bytes.fromBigInt(oneString).toHexString() {}", [Bytes.fromBigInt(oneString).toHexString()]);
log.info("Bytes.fromBigInt(one).toHexString() {}", [Bytes.fromBigInt(one).toHexString()]);    

log.info("oneString.toI32().toString() {}", [oneString.toI32().toString()]);
log.info("one.toI32().toString() {}", [one.toI32().toString()]);

The result in MatchStick is

💬 Bytes.fromBigInt(oneString).toHexString() 0x01
💬 Bytes.fromBigInt(one).toHexString() 0x01000000
💬 oneString.toI32().toString() 1
💬 one.toI32().toString() 1

So, the BigInt that was creates from i32 has appending zeros when converted to Bytes. Why?

[maoueh]

Seems to me that there is a problem indeed and I think it's again an endianess problem. I think the problem is maybe BigInt.fromI32(1 as i32);, implementation is:

  static fromI32(x: i32): BigInt {
    const byteArray = ByteArray.fromI32(x);
    return BigInt.fromByteArray(byteArray);
  }

While Bytes.fromBigInt simply case the BigInt into Bytes directly. I would need more checks. Could you share a sample to reproduce your tests?

I would like to try:

let oneBytes = ByteArray.fromI32(1 as i32);
let oneReversed = BigInt.fromByteArray(oneBytes.reverse());

log.info("Bytes.fromBigInt(oneReversed).toHexString() {}", [Bytes.fromBigInt(oneReversed).toHexString()]);    

Note Untested code

[rolandsaven]

@maoueh It's basically an empty subgraph with matchstick and running the script that I pasted above.

I've run your code: (I had to change type though)

let oneBytes = ByteArray.fromI32(1 as i32);
let oneReversed = BigInt.fromByteArray(changetype<ByteArray>(oneBytes.reverse()));

log.info("Bytes.fromBigInt(oneReversed).toHexString() {}", [Bytes.fromBigInt(oneReversed).toHexString()]); 

💬 Bytes.fromBigInt(oneReversed).toHexString() 0x00000001

[maoueh]

Ok so definitely again an endianness problem, not quite sure how we are going to fix that. I say how because I think this will be a breaking change and quite silent.