transfer hook: add new offchain helper

token/program-2022/src/offchain.rs

@@ -1,6 +1,7 @@
 //! Offchain helper for fetching required accounts to build instructions
 
 pub use spl_transfer_hook_interface::offchain::{AccountDataResult, AccountFetchError};
+#[allow(deprecated)]
 use {
     crate::{
         extension::{transfer_hook, StateWithExtensions},
@@ -33,6 +34,7 @@ use {
 ///     &mint,
 /// ).await?;
 /// ```
+#[allow(deprecated)]
 pub async fn resolve_extra_transfer_account_metas<F, Fut>(
     instruction: &mut Instruction,
     fetch_account_data_fn: F,

token/transfer-hook/interface/Cargo.toml

@@ -20,5 +20,8 @@ spl-pod = { version = "0.1", path = "../../../libraries/pod" }
 [lib]
 crate-type = ["cdylib", "lib"]
 
+[dev-dependencies]
+tokio = { version = "1.35.1", features = ["full"] }
+
 [package.metadata.docs.rs]
 targets = ["x86_64-unknown-linux-gnu"]

token/transfer-hook/interface/src/offchain.rs

@@ -2,7 +2,11 @@
 
 pub use spl_tlv_account_resolution::state::{AccountDataResult, AccountFetchError};
 use {
-    crate::{get_extra_account_metas_address, instruction::ExecuteInstruction},
+    crate::{
+        error::TransferHookError,
+        get_extra_account_metas_address,
+        instruction::{execute, ExecuteInstruction},
+    },
     solana_program::{
         instruction::{AccountMeta, Instruction},
         program_error::ProgramError,
@@ -35,6 +39,10 @@ use {
 ///     &program_id,
 /// ).await?;
 /// ```
+#[deprecated(
+    since = "0.5.0",
+    note = "Please use `add_extra_account_metas_for_execute` instead"
+)]
 pub async fn resolve_extra_account_metas<F, Fut>(
     instruction: &mut Instruction,
     fetch_account_data_fn: F,
@@ -68,3 +76,236 @@ where
 
     Ok(())
 }
+
+/// Offchain helper to get all additional required account metas for an execute
+/// instruction, based on a validation state account.
+///
+/// To be client-agnostic and to avoid pulling in the full solana-sdk, this
+/// simply takes a function that will return its data as `Future<Vec<u8>>` for
+/// the given address. Can be called in the following way:
+///
+/// ```rust,ignore
+/// add_extra_account_metas_for_execute(
+///     &mut instruction,
+///     &program_id,
+///     &source,
+///     &mint,
+///     &destination,
+///     &authority,
+///     amount,
+///     |address| self.client.get_account(&address).map_ok(|opt| opt.map(|acc| acc.data)),
+/// )
+/// .await?;
+/// ```
+#[allow(clippy::too_many_arguments)]
+pub async fn add_extra_account_metas_for_execute<F, Fut>(
+    instruction: &mut Instruction,
+    program_id: &Pubkey,
+    source_pubkey: &Pubkey,
+    mint_pubkey: &Pubkey,
+    destination_pubkey: &Pubkey,
+    authority_pubkey: &Pubkey,
+    amount: u64,
+    fetch_account_data_fn: F,
+) -> Result<(), AccountFetchError>
+where
+    F: Fn(Pubkey) -> Fut,
+    Fut: Future<Output = AccountDataResult>,
+{
+    let validate_state_pubkey = get_extra_account_metas_address(mint_pubkey, program_id);
+    let validate_state_data = fetch_account_data_fn(validate_state_pubkey)
+        .await?
+        .ok_or(ProgramError::InvalidAccountData)?;
+
+    // Check to make sure the provided keys are in the instruction
+    if [
+        source_pubkey,
+        mint_pubkey,
+        destination_pubkey,
+        authority_pubkey,
+    ]
+    .iter()
+    .any(|&key| !instruction.accounts.iter().any(|meta| meta.pubkey == *key))
+    {
+        Err(TransferHookError::IncorrectAccount)?;
+    }
+
+    let mut execute_instruction = execute(
+        program_id,
+        source_pubkey,
+        mint_pubkey,
+        destination_pubkey,
+        authority_pubkey,
+        &validate_state_pubkey,
+        amount,
+    );
+
+    ExtraAccountMetaList::add_to_instruction::<ExecuteInstruction, _, _>(
+        &mut execute_instruction,
+        fetch_account_data_fn,
+        &validate_state_data,
+    )
+    .await?;
+
+    // Add only the extra accounts resolved from the validation state
+    instruction
+        .accounts
+        .extend_from_slice(&execute_instruction.accounts[5..]);
+
+    // Add the program id and validation state account
+    instruction
+        .accounts
+        .push(AccountMeta::new_readonly(*program_id, false));
+    instruction
+        .accounts
+        .push(AccountMeta::new_readonly(validate_state_pubkey, false));
+
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use {
+        super::*,
+        spl_tlv_account_resolution::{account::ExtraAccountMeta, seeds::Seed},
+        tokio,
+    };
+
+    const PROGRAM_ID: Pubkey = Pubkey::new_from_array([1u8; 32]);
+    const EXTRA_META_1: Pubkey = Pubkey::new_from_array([2u8; 32]);
+    const EXTRA_META_2: Pubkey = Pubkey::new_from_array([3u8; 32]);
+
+    // Mock to return the validation state account data
+    async fn mock_fetch_account_data_fn(_address: Pubkey) -> AccountDataResult {
+        let extra_metas = vec![
+            ExtraAccountMeta::new_with_pubkey(&EXTRA_META_1, true, false).unwrap(),
+            ExtraAccountMeta::new_with_pubkey(&EXTRA_META_2, true, false).unwrap(),
+            ExtraAccountMeta::new_with_seeds(
+                &[
+                    Seed::AccountKey { index: 0 }, // source
+                    Seed::AccountKey { index: 2 }, // destination
+                    Seed::AccountKey { index: 4 }, // validation state
+                ],
+                false,
+                true,
+            )
+            .unwrap(),
+            ExtraAccountMeta::new_with_seeds(
+                &[
+                    Seed::InstructionData {
+                        index: 8,
+                        length: 8,
+                    }, // amount
+                    Seed::AccountKey { index: 2 }, // destination
+                    Seed::AccountKey { index: 5 }, // extra meta 1
+                    Seed::AccountKey { index: 7 }, // extra meta 3 (PDA)
+                ],
+                false,
+                true,
+            )
+            .unwrap(),
+        ];
+        let account_size = ExtraAccountMetaList::size_of(extra_metas.len()).unwrap();
+        let mut data = vec![0u8; account_size];
+        ExtraAccountMetaList::init::<ExecuteInstruction>(&mut data, &extra_metas)?;
+        Ok(Some(data))
+    }
+
+    #[tokio::test]
+    async fn test_add_extra_account_metas_for_execute() {
+        let source = Pubkey::new_unique();
+        let mint = Pubkey::new_unique();
+        let destination = Pubkey::new_unique();
+        let authority = Pubkey::new_unique();
+        let amount = 100u64;
+
+        let validate_state_pubkey = get_extra_account_metas_address(&mint, &PROGRAM_ID);
+        let extra_meta_3_pubkey = Pubkey::find_program_address(
+            &[
+                source.as_ref(),
+                destination.as_ref(),
+                validate_state_pubkey.as_ref(),
+            ],
+            &PROGRAM_ID,
+        )
+        .0;
+        let extra_meta_4_pubkey = Pubkey::find_program_address(
+            &[
+                amount.to_le_bytes().as_ref(),
+                destination.as_ref(),
+                EXTRA_META_1.as_ref(),
+                extra_meta_3_pubkey.as_ref(),
+            ],
+            &PROGRAM_ID,
+        )
+        .0;
+
+        // Fail missing key
+        let mut instruction = Instruction::new_with_bytes(
+            PROGRAM_ID,
+            &[],
+            vec![
+                // source missing
+                AccountMeta::new_readonly(mint, false),
+                AccountMeta::new(destination, false),
+                AccountMeta::new_readonly(authority, true),
+            ],
+        );
+        assert_eq!(
+            add_extra_account_metas_for_execute(
+                &mut instruction,
+                &PROGRAM_ID,
+                &source,
+                &mint,
+                &destination,
+                &authority,
+                amount,
+                mock_fetch_account_data_fn,
+            )
+            .await
+            .unwrap_err()
+            .downcast::<TransferHookError>()
+            .unwrap(),
+            Box::new(TransferHookError::IncorrectAccount)
+        );
+
+        // Success
+        let mut instruction = Instruction::new_with_bytes(
+            PROGRAM_ID,
+            &[],
+            vec![
+                AccountMeta::new(source, false),
+                AccountMeta::new_readonly(mint, false),
+                AccountMeta::new(destination, false),
+                AccountMeta::new_readonly(authority, true),
+            ],
+        );
+        add_extra_account_metas_for_execute(
+            &mut instruction,
+            &PROGRAM_ID,
+            &source,
+            &mint,
+            &destination,
+            &authority,
+            amount,
+            mock_fetch_account_data_fn,
+        )
+        .await
+        .unwrap();
+
+        let check_metas = [
+            AccountMeta::new(source, false),
+            AccountMeta::new_readonly(mint, false),
+            AccountMeta::new(destination, false),
+            AccountMeta::new_readonly(authority, true),
+            AccountMeta::new_readonly(EXTRA_META_1, true),
+            AccountMeta::new_readonly(EXTRA_META_2, true),
+            AccountMeta::new(extra_meta_3_pubkey, false),
+            AccountMeta::new(extra_meta_4_pubkey, false),
+            AccountMeta::new_readonly(PROGRAM_ID, false),
+            AccountMeta::new_readonly(validate_state_pubkey, false),
+        ];
+
+        assert_eq!(instruction.accounts, check_metas);
+    }
+}