Error: AnchorError occurred. Error Code: InstructionDidNotDeserialize. Error Number: 102. The program could not deserialize the given instruction

Question

Hi I am creating a split bill and pay smart contract. I have written a small piece of code to begin with here it is:

use anchor_lang::prelude::*;

declare_id!("BpvN4cCL5RxjxQk2ikVbXAA2bskMZgH4eveiy41Wg3FV");

#[program]
pub mod split_bill {
    use super::*;

    pub fn initialize_split(ctx: Context<InitializeSplit>, name: String, total_amount: u64,) -> Result<()> {

        let split_bill = &mut ctx.accounts.bill;
        split_bill.authority = ctx.accounts.initializer.key();
        split_bill.bill_name = name;
        split_bill.total_amount = total_amount;
        split_bill.contributors = Vec::new();
        Ok(())
    }
}

#[account]
#[derive(InitSpace)]
pub struct SplitBill {
    pub authority: Pubkey,

    #[max_len(50)]
    pub bill_name: String,
    pub total_amount: u64,

    #[max_len(10, 40)]
    pub contributors: Vec<Contributor>,
}

#[derive(AnchorSerialize, AnchorDeserialize, Clone, InitSpace)]
pub struct Contributor{
    pub address: Pubkey,
    pub amount: u64,
}

#[derive(Accounts)]
#[instruction(authority:Pubkey, bill_name: String)]
pub struct InitializeSplit<'info> {
    #[account(mut)]
    pub initializer: Signer<'info>,

    #[account(
        init,
        space = 8 + SplitBill::INIT_SPACE,
        payer = initializer,
        seeds = [authority.key().as_ref(), bill_name.as_ref(), ],
        bump,    
    )]
    pub bill: Account<'info, SplitBill>,

    /// CHECK: This account is not loaded in this instruction and serves only as a destination for the final transfer.
    pub receiver: AccountInfo<'info>,
    pub system_program: Program<'info, System>,
}

I wrote a test script to test it:

import * as anchor from "@coral-xyz/anchor";
import { Program } from "@coral-xyz/anchor";
import { SplitBill } from "../target/types/split_bill";
import { startAnchor } from "solana-bankrun";
import { BankrunProvider } from "anchor-bankrun";
import {PublicKey} from '@solana/web3.js';
import { expect } from "chai";

const IDL = require("../target/idl/split_bill.json");
const programId = new PublicKey("BpvN4cCL5RxjxQk2ikVbXAA2bskMZgH4eveiy41Wg3FV");

describe("split-bill", () => {
  
  let context;
  let provider;
  let program: Program<SplitBill>;

  before(async () => {
    context = await startAnchor("", [{name:"split_bill", programId: programId}], []);
    provider = new BankrunProvider(context);
    program = new Program<SplitBill>(IDL, provider);
  });

  it("Initialize a split bill", async () => {

    console.log("initialize split");

    const [splitBillAddress] = await PublicKey.findProgramAddressSync(
      [provider.wallet.publicKey.toBuffer(), Buffer.from("test"), ],
      programId);

    console.log("splitBillAddress", splitBillAddress.toBase58());

    const tx = await program.methods.initializeSplit("test", new anchor.BN(1000)).accountsPartial({
      bill: splitBillAddress,
      receiver: provider.wallet.publicKey,
    }).rpc();

    console.log("initialize split done");
  });
});

And I am getting this error:

1) split-bill
       Initialize a split bill:
     Error: AnchorError occurred. Error Code: InstructionDidNotDeserialize. Error Number: 102. Error Message: The program could not deserialize the given instruction.
      at Function.parse (node_modules/@coral-xyz/anchor/src/error.ts:136:14)
      at translateError (node_modules/@coral-xyz/anchor/src/error.ts:277:35)
      at MethodsBuilder.rpc [as _rpcFn] (node_modules/@coral-xyz/anchor/src/program/namespace/rpc.ts:35:29)

Please Help Thanks.

Answer 1

In your instruction macro, #[instruction(authority: Pubkey, bill_name: String)] you are using authority but aren't passing in this address in your initialize_split function.

initialize_split(ctx: Context<InitializeSplit>, authority: Pubkey, name: String, total_amount: u64,)