Je eerste Solana-programma implementeren

use anchor_lang::prelude::*;

// This is your program's public key and it will update
// automatically when you build the project.
declare_id!("11111111111111111111111111111111");

#[program]
mod hello_anchor {
    use super::*;
    pub fn initialize(ctx: Context<Initialize>, data: u64) -> Result<()> {
        ctx.accounts.new_account.data = data;
        msg!("Changed data to: {}!", data); // Message will show up in the tx logs
        Ok(())
    }
}

#[derive(Accounts)]
pub struct Initialize<'info> {
    // We must specify the space in order to initialize an account.
    // First 8 bytes are default account discriminator,
    // next 8 bytes come from NewAccount.data being type u64.
    // (u64 = 64 bits unsigned integer = 8 bytes)
    #[account(
      init,
      payer = signer,
      space = 8 + 8
    )]
    pub new_account: Account<'info, NewAccount>,
    #[account(mut)]
    pub signer: Signer<'info>,
    pub system_program: Program<'info, System>,
}

#[account]
pub struct NewAccount {
    data: u64
}

// No imports needed: web3, anchor, pg and more are globally available

describe("Test", () => {
  it("initialize", async () => {
    // Generate keypair for the new account
    const newAccountKp = new web3.Keypair();

    // Send transaction
    const data = new BN(42);
    const txHash = await pg.program.methods
      .initialize(data)
      .accounts({
        newAccount: newAccountKp.publicKey,
        signer: pg.wallet.publicKey,
        systemProgram: web3.SystemProgram.programId
      })
      .signers([newAccountKp])
      .rpc();
    console.log(`Use 'solana confirm -v ${txHash}' to see the logs`);

    // Confirm transaction
    await pg.connection.confirmTransaction(txHash);

    // Fetch the created account
    const newAccount = await pg.program.account.newAccount.fetch(
      newAccountKp.publicKey
    );

    console.log("On-chain data is:", newAccount.data.toString());

    // Check whether the data on-chain is equal to local 'data'
    assert(data.eq(newAccount.data));
  });
});