solana: add counter to dummy transfer hook

to be able to test if it was executed

Author: kcsongor

solana/programs/dummy-transfer-hook/src/lib.rs

@@ -17,7 +17,7 @@ pub const DESTINATION_TOKEN_ACCOUNT_INDEX: u8 = 2;
 pub const AUTHORITY_ACCOUNT_INDEX: u8 = 3;
 
 /// Number of extra accounts in the ExtraAccountMetaList account
-pub const EXTRA_ACCOUNTS_LEN: u8 = 1;
+pub const EXTRA_ACCOUNTS_LEN: u8 = 2;
 
 #[program]
 pub mod dummy_transfer_hook {
@@ -31,21 +31,30 @@ pub mod dummy_transfer_hook {
     pub fn initialize_extra_account_meta_list(
         ctx: Context<InitializeExtraAccountMetaList>,
     ) -> Result<()> {
-        let account_metas = vec![ExtraAccountMeta::new_with_seeds(
-            &[
-                Seed::Literal {
-                    bytes: "dummy_account".as_bytes().to_vec(),
-                },
-                // owner field of the sender token account
-                Seed::AccountData {
-                    account_index: SENDER_TOKEN_ACCOUNT_INDEX,
-                    data_index: 32,
-                    length: 32,
-                },
-            ],
-            false, // is_signer
-            false, // is_writable
-        )?];
+        let account_metas = vec![
+            ExtraAccountMeta::new_with_seeds(
+                &[
+                    Seed::Literal {
+                        bytes: "dummy_account".as_bytes().to_vec(),
+                    },
+                    // owner field of the sender token account
+                    Seed::AccountData {
+                        account_index: SENDER_TOKEN_ACCOUNT_INDEX,
+                        data_index: 32,
+                        length: 32,
+                    },
+                ],
+                false, // is_signer
+                false, // is_writable
+            )?,
+            ExtraAccountMeta::new_with_seeds(
+                &[Seed::Literal {
+                    bytes: "counter".as_bytes().to_vec(),
+                }],
+                false, // is_signer
+                true,  // is_writable
+            )?,
+        ];
 
         assert_eq!(EXTRA_ACCOUNTS_LEN as usize, account_metas.len());
 
@@ -58,8 +67,8 @@ pub mod dummy_transfer_hook {
         Ok(())
     }
 
-    pub fn transfer_hook(_ctx: Context<TransferHook>, _amount: u64) -> Result<()> {
-        // NOTE: for now, the account constraints implement all the restrictions.
+    pub fn transfer_hook(ctx: Context<TransferHook>, _amount: u64) -> Result<()> {
+        ctx.accounts.counter.count += 1;
         Ok(())
     }
 
@@ -87,6 +96,12 @@ pub mod dummy_transfer_hook {
     }
 }
 
+#[account]
+#[derive(InitSpace)]
+pub struct Counter {
+    pub count: u64,
+}
+
 #[derive(Accounts)]
 pub struct InitializeExtraAccountMetaList<'info> {
     #[account(mut)]
@@ -104,6 +119,16 @@ pub struct InitializeExtraAccountMetaList<'info> {
     pub mint: InterfaceAccount<'info, Mint>,
     pub token_program: Interface<'info, TokenInterface>,
     pub associated_token_program: Program<'info, AssociatedToken>,
+
+    #[account(
+        init,
+        payer = payer,
+        space = 8 + Counter::INIT_SPACE,
+        seeds = [b"counter"],
+        bump
+    )]
+    pub counter: Account<'info, Counter>,
+
     pub system_program: Program<'info, System>,
 }
 
@@ -136,4 +161,11 @@ pub struct TransferHook<'info> {
     /// CHECK: dummy account. It just tests that the off-chain code correctly
     /// computes and the on-chain code correctly passes on the PDA.
     pub dummy_account: AccountInfo<'info>,
+
+    #[account(
+        mut,
+        seeds = [b"counter"],
+        bump
+    )]
+    pub counter: Account<'info, Counter>,
 }

solana/tests/example-native-token-transfer.ts

@@ -61,6 +61,16 @@ describe("example-native-token-transfers", () => {
     dummyTransferHook.programId
   );
 
+  const [counterPDA] = PublicKey.findProgramAddressSync(
+    [Buffer.from("counter")],
+    dummyTransferHook.programId
+  );
+
+  async function counterValue(): Promise<anchor.BN> {
+    const counter = await dummyTransferHook.account.counter.fetch(counterPDA);
+    return counter.count
+  }
+
   it("Initialize mint", async () => {
     const extensions = [spl.ExtensionType.TransferHook];
     const mintLen = spl.getMintLen(extensions);
@@ -128,6 +138,7 @@ describe("example-native-token-transfers", () => {
         .accountsStrict({
           payer: payer.publicKey,
           mint: mint.publicKey,
+          counter: counterPDA,
           extraAccountMetaList: extraAccountMetaListPDA,
           tokenProgram: spl.TOKEN_2022_PROGRAM_ID,
           associatedTokenProgram: spl.ASSOCIATED_TOKEN_PROGRAM_ID,
@@ -243,6 +254,7 @@ describe("example-native-token-transfers", () => {
 
       // TODO: assert other stuff in the message
       // console.log(nttManagerMessage);
+      expect((await counterValue()).toString()).to.be.eq("1")
     });
 
     it("Can receive tokens", async () => {
@@ -300,6 +312,8 @@ describe("example-native-token-transfers", () => {
       });
 
       expect(released).to.equal(true);
+
+      expect((await counterValue()).toString()).to.be.eq("2")
     });
   });