Create Token extension mint results in "invalid account data for instruction"

Question

I am trying to create a token mint with extension in anchor. This works fine until I try to to add an additional extension to the mint. When I call:

let space =
    ExtensionType::try_calculate_account_len::<Mint>(&[ExtensionType::MetadataPointer]).unwrap();

The size output for the mint is: "Mint Space: 234 lamports: 2519520"

The error is:

Error: InvalidAccountData

So i assume the space calculation for the mint is wrong.

When I try to change it to

let space =
    ExtensionType::try_calculate_account_len::<Mint>(&[ExtensionType::TokenMetadata]).unwrap();

the error turns into:

"panicked at 'called `Result::unwrap()` on an `Err` value: InvalidArgument', programs/extension_nft/src/instructions/mint_nft.rs:19:91"

Is that because TokenMetadata has variable length?

ExtensionType::TokenMetadata => unreachable!(),

How can I create a Mint with Token meta data in anchor/rust?

Here is the code:

let space = ExtensionType::try_calculate_account_len::<Mint>(&[ExtensionType::MetadataPointer])
        .unwrap();

let lamports_required = (Rent::get()?).minimum_balance(space);
msg!(
    "Meta data Space: {} lamports: {}",
    space as u64,
    lamports_required
);

system_program::create_account(
    CpiContext::new(
        ctx.accounts.token_program.to_account_info(),
        system_program::CreateAccount {
            from: ctx.accounts.signer.to_account_info(),
            to: ctx.accounts.mint.to_account_info(),
        },
    ),
    lamports_required,
    space as u64,
    &ctx.accounts.token_program.key(),
)?;

system_program::assign(
    CpiContext::new(
        ctx.accounts.token_program.to_account_info(),
        system_program::Assign {
            account_to_assign: ctx.accounts.mint.to_account_info(),
        },
    ),
    &token_2022::ID,
)?;

msg!("Created mint account");

let mint_cpi = CpiContext::new(
    ctx.accounts.token_program.to_account_info(),
    token_2022::InitializeMint2 {
        mint: ctx.accounts.mint.to_account_info(),
    },
);
msg!("Init mint");

token_2022::initialize_mint2(mint_cpi, 0, &ctx.accounts.signer.key(), None).unwrap();

Answer 1

Ohhh i figured the first part out!

I need to initialize the metadata pointer before initializing the mint:

let instruction = spl_token_2022::extension::metadata_pointer::instruction::initialize(
    &Token2022::id(),
    &ctx.accounts.mint.key(),
    Some(ctx.accounts.signer.key()),
    Some(ctx.accounts.signer.key()),
)
.unwrap();
invoke(
    &instruction,
    &[
        ctx.accounts.mint.to_account_info(),
        ctx.accounts.signer.to_account_info(),
        ctx.accounts.signer.to_account_info(),
    ],
)?;
token_2022::initialize_mint2(mint_cpi, 0, &ctx.accounts.signer.key(), None).unwrap();

The second part of creating the meta data looks like this:

invoke(
    &spl_token_metadata_interface::instruction::initialize(
        &spl_token_2022::id(),
        ctx.accounts.mint.key,
        ctx.accounts.signer.key,
        ctx.accounts.mint.key,
        ctx.accounts.signer.key,
         "Epic Fish".to_string(),
         "EPC".to_string(),
         "https://shdw-drive.genesysgo.net/AzjHvXgqUJortnr5fXDG2aPkp2PfFMvu4Egr57fdiite/PirateCoinMeta".to_string(),

    ),
    &[ctx.accounts.mint.to_account_info().clone(), ctx.accounts.signer.to_account_info().clone()],
)?;

Also the pointer extension needs to be initialized before the mint and the meta data itself after the mint.

For that you also need to add

spl-token-metadata-interface = { version = "0.2.1"}

to your cargo.toml