how to make a proper schema for the arguments

Question

there are arguments

      "args": [
        {
          "name": "decimals",
          "type": "u8"
        },
        {
          "name": "mintAuthority",
          "type": "publicKey"
        },
        {
          "name": "freezeAuthority",
          "type": {
            "defined": "COption<Pubkey>"
          }
        }
      ]

How to make the correct schema to be used in borsh.js?

I tried something like this

const schema = {
  struct: {
    decimals: "u8",
    mintAuthority: "string",
    freezeAuthority: "string",
  },
};

or

class MyArgs {
  decimals: u8;
  mintAuthority: PublicKey;
  freezeAuthority: COption<Pubkey> | null;

  constructor(decimals: u8, mintAuthority: PublicKey, freezeAuthority: COption<Pubkey> | null) {
    this.decimals = decimals;
    this.mintAuthority = mintAuthority;
    this.freezeAuthority = freezeAuthority;
  }
}

const MyArgsSchema = new Map([
  [
    MyArgs,
    {
      kind: 'struct',
      fields: [
        ['decimals', 'u8'],
        ['mintAuthority', 'publicKey'],
        ['freezeAuthority', { kind: 'option', type: 'publicKey' }],
      ],
    },
  ],
]);

const data = "bT1LdJiCtzLAHMaiFmacn9H5oEZbRNsD6un3YxFXLYX6aixPPcaebNgLjwnMxzsEQ7uHaVmG3f5MPax7VEPAbJXYY1Q";

const resultDecode = deserialize(
  MyArgsSchema, // MyArgsSchema or schema
  Buffer.from(bs58.decode(data)),
);
console.log(resultDecode); // Error Invalid schema....

but it threw an error

Error: Invalid schema: {} expected option, enum, array, set, map, struct or u8, u16, u32, u64, u128, i8, i16, i32, i64, i128, f32, f64, bool, string

How to correctly specify the type for publicKey and

"type": {
   "defined": "COption<Pubkey>"
 }

i`m use "borsh": "^2.0.0" version, "bs58": "^5.0.0",

Answer 1

Pubkey is not part of the borsh specification. It can be represented as a [u8; 32] instead. Should look something like:

class MyArgs {
  decimals: u8;
  mintAuthority: PublicKey;
  freezeAuthority: Pubkey | null;

  constructor(decimals: u8, mintAuthority: Uint8Array, freezeAuthority: Uint8Array | null) {
    this.decimals = decimals;
    this.mintAuthority = new PublicKey(mintAuthority);
    this.freezeAuthority = freezeAuthority !== null ? new PublicKey(mintAuthority) : null ;
  }
}

const MyArgsSchema = new Map([
  [
    MyArgs,
    {
      kind: 'struct',
      fields: [
        ['decimals', 'u8'],
        ['mintAuthority', '[32]'],
        ['freezeAuthority', { kind: 'option', type: '[32]' }],
      ],
    },
  ],
]);