token-js: Added support for transfer hook instructions

[wjthieme]

resolves: #4337

[wjthieme]

@joncinque is it currently possible to update the transfer hook authority (optionally set it to null)? If so where would I find the spec for that?

[joncinque]

Really great work! Nothing big, just a few nits to sort out. After looking through this, I'm thinking the TransferHookAccount extension can get added separately, since this is very neatly contained.

Regarding your question:

is it currently possible to update the transfer hook authority (optionally set it to null)? If so where would I find the spec for that?

It certainly is, you can find the program source code doing it at

solana-program-library/token/program-2022/src/processor.rs

Lines 810 to 822 in 47f09c9

	AuthorityType::TransferHookProgramId => {
	let extension = mint.get_extension_mut::<TransferHook>()?;
	let maybe_authority: Option<Pubkey> = extension.authority.into();
	let authority = maybe_authority.ok_or(TokenError::AuthorityTypeNotSupported)?;
	Self::validate_owner(
	program_id,
	&authority,
	authority_info,
	authority_info_data_len,
	account_info_iter.as_slice(),
	)?;
	extension.authority = new_authority.try_into()?;
	}

The concept is that you can reuse set-authority and pass in the correct authority. Given the disparity between the Rust side:

solana-program-library/token/program-2022/src/instruction.rs

Lines 1042 to 1070 in 47f09c9

	pub enum AuthorityType {
	/// Authority to mint new tokens
	MintTokens,
	/// Authority to freeze any account associated with the Mint
	FreezeAccount,
	/// Owner of a given token account
	AccountOwner,
	/// Authority to close a token account
	CloseAccount,
	/// Authority to set the transfer fee
	TransferFeeConfig,
	/// Authority to withdraw withheld tokens from a mint
	WithheldWithdraw,
	/// Authority to close a mint account
	CloseMint,
	/// Authority to set the interest rate
	InterestRate,
	/// Authority to transfer or burn any tokens for a mint
	PermanentDelegate,
	/// Authority to update confidential transfer mint and aprove accounts for confidential
	/// transfers
	ConfidentialTransferMint,
	/// Authority to set the transfer hook program id
	TransferHookProgramId,
	/// Authority to set the withdraw withheld authority encryption key
	ConfidentialTransferFeeConfig,
	/// Authority to set the metadata address
	MetadataPointer,
	}

and the JS side

solana-program-library/token/js/src/instructions/setAuthority.ts

Lines 16 to 21 in 47f09c9

	export enum AuthorityType {
	MintTokens = 0,
	FreezeAccount = 1,
	AccountOwner = 2,
	CloseAccount = 3,
	}

We have a bit of work to do there 😅 I put in #5100 to address that

[wjthieme]

Will do the changes!

The concept is that you can reuse set-authority and pass in the correct authority

That is what I figured. Just didn't see it for other extension authorities like the transfer fee extension.

[joncinque]

Great job, thanks for the contribution!