SDK fails when Contract returns `String` in a `Struct` or `Tuple`

[pedronauck]

What version of fuels-ts are you using?

0.65.0

Steps to Reproduce

Hey guys, I was trying to run a small project yesterday and got into some issues related to decoding contract calls. What's happening is that it is not possible to return a Struct or a tuple that contains a String or Bytes inside. It seems it worked before 0.58.0, but things started to break since this PR.

Expected Behavior

This is the example of code in Sway

This is the example of usage on the SDK:

  static async getFirstMessage() {
    const contract = await getContract();
    const { value } = await contract.functions.get_first_msg().simulate();
    console.log(value);
  }

Actual Behavior

And that's the error I'm facing right now:

Seems that the problem is related to this part of the code:
https://github.com/FuelLabs/fuels-ts/blob/master/packages/abi-coder/src/coders/stdString.ts#L52-L58

I don't know, but I guess this toNumber() error when tryting to convert from bn will break other decoders as well.

[camsjams]

Relates to FuelLabs/sway#5044

[camsjams]

Hey @pedronauck after debugging, this looks to be an issue on Sway with the new String Slice changes that have been added.

Are you able to share more of the contract source code (as text, not image 😅 ). Currently, a storage map like StorageMap<String, u64> = StorageMap {} or similar heap types (Bytes/Strings/Vectors) will not function correctly.

[Torres-ssf]

This is currently blocked:
ref:

• Improving slice sway#5110