Add a helper for the conversion: bytecode file contents -> `Vec<u8>`

[Dhaiwat10]

We need a helper function to read bytecode from a file and convert that to a bytearray that users can pass into our sway-libs functions related to bytecode: https://github.com/FuelLabs/sway-libs/tree/master/libs/bytecode

This conversion is required because the bytecode from a file is a string, but the type that these Sway functions accept for the bytecode is a Vec<u8> - which in JavaScript-land is a Vec<BigNumberish>.

This helper would convert the string to the proper type and ensure all the data is correctly packed.

Possible API

const bytecodeFromFile = readFile(pathToBytecode); // string

const bytecodeVec = generateBytecodeVecFromString(bytecodeFromFile); // our helper -> returns `Vec<BigNumberish>`

await contract.functions.verify_bytecode(bytecodeVec);

Incoming from feedback from the development work being done on the Fuelnaut project: FuelLabs/docs-hub#203

The Fuelnaut project is blocked for now until we figure this out.

[Dhaiwat10]

cc @sarahschwartz

[arboleya]

@Dhaiwat10 You mean the contract bytecode needs to be sent as an argument to another contract/function call?

[Dhaiwat10]

@arboleya precisely

[nedsalk]

If we were to treat Vec<u8> as number[] | Uint8Array then we can do simply do this:

import { arrayify } from 'fuels';

const bytecodeFromFile = readFile(pathToBytecode); // string

await contract.functions.verify_bytecode(arrayify(bytecodeFromFile));

---

On first look, it seems to me that this wouldn't even require any change to the runtime behavior in VecCoder:

pointer.dynamicData = {
  0: concatWithDynamicData(Array.from(value).map((v) => this.coder.encode(v))),
};

Array.from can accept Uint8Array out of the box the same way it'd accept a regular number[]:

Array.from(new Uint8Array([1,2,3]));
// Array(3) [1, 2, 3]

Array.from([1,2,3]);
// Array(3) [1, 2, 3]

[nedsalk]

@sarahschwartz Could you try my proposal from above? You'd have to do something like this:

await contract.functions.verify_bytecode(arrayify(bytecodeFromFile) as unknown as number[]);

[sarahschwartz]

@sarahschwartz Could you try my proposal from above? You'd have to do something like this:

await contract.functions.verify_bytecode(arrayify(bytecodeFromFile) as unknown as number[]);

I tried this, but i get this error:

FuelnautLevel.tsx:136 Error deploying new instance: FuelError: Expected array value.
    at VecCoder.encode (index.mjs:723:13)
    at eval (index.mjs:687:31)
    at Array.map (<anonymous>)
    at TupleCoder.encode (index.mjs:686:19)
    at FunctionFragment.encodeArguments (index.mjs:1226:27)
    at createContractCall (index.mjs:805:21)

Here is my code for reference:

Sway Contract:

  fn verify_bytecode_test(bytecode_input: Vec<u8>){
        let mut bytecode = bytecode_input;
        let root = compute_bytecode_root(bytecode);
        log(root);
    }

Next.js app:

// server side
const byteCodePath = join(
      fuelnautPath,
      `${levelKey}/out/debug/${levelKey}.bin`,
    );
const bytecode = readFileSync(byteCodePath);
const base64Bytecode = bytecode.toString('base64');

// client side
const bytecodeBuffer = Buffer.from(base64Bytecode, 'base64');
const input = arrayify(bytecodeBuffer) as unknown as number[];
console.log("INPUT:", input)
await contract.functions
    .verify_bytecode_test(input)
    .txParams({ gasPrice: 1, gasLimit: 1_000_000 })
    .call();

I can log the input though:

INPUT: Uint8Array(1260) [116, 0, 0, 3, 71, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 100, 93, 252, 192, 1, 16, 255, 243, 0, 93, 64, 96, 73, 93, 71, 240, 14, 19, 73, 4, 64, 118, 72, 0, 5, 93, 71, 240, 15, 19, 73, 4, 64, 118, 72, 0, 123, 114, 240, 0, 123, 54, 240, 0, 0, 26, 236, 80, 0, 145, 0, 2, 24, 93, 67, 240, 16, 16, 65, 3, 0, 93, 71, 240, 16, 16, 69, 19, 0, 114, 72, 0, 32, 40, 237, 4, 128, 95, 236, 0, 4, 80, 75, 176, 40, …]