How to use account data in a Solana program test

serum_account.rs

#![cfg(feature = "test-bpf")]

// first, grab some account data, e.g.
// ```shell
// solana account -u m SRMuApVNdxXokk5GT7XD5cUUgXMBCoAz2LHeuAoKWRt --output-file account.bin
// ```

mod helpers;

use helpers::*;
use solana_program::{
    account_info::AccountInfo,
    pubkey::Pubkey,
    program_error::ProgramError,
    program_pack::{Pack, IsInitialized}
};
use solana_program_test::*;
use solana_sdk::{
    account::Account,
    account_info::IntoAccountInfo,
};
use std::str::FromStr;

#[tokio::test]
async fn test_success() {
    // construct Pubkey
    let pubkey = Pubkey::from_str("SRMuApVNdxXokk5GT7XD5cUUgXMBCoAz2LHeuAoKWRt").unwrap();

    // construct Account with the data
    let mut account = Account {
        lamports: u32::MAX as u64,
        data: read_file(find_file("account.bin").unwrap()),
        owner: Pubkey::new(&[0; 32]),
        executable: false,
        rent_epoch: 0,
    };

    // construct AccountInfo from tuple (key, is_signer, account)
    let account_info = (&pubkey, false, &mut account).into_account_info();

    // unpack AccountInfo into a known type (in this case, an SPL Token Mint)
    let srm_mint = unpack::<spl_token::state::Mint>(&account_info).unwrap();

    // ...
}

fn unpack<T: Pack + IsInitialized>(
    account_info: &AccountInfo,
) -> Result<T, ProgramError> {
    T::unpack(&account_info.data.borrow())
}