instruction macro and simplification

utils/src/loaders.rs

@@ -146,6 +146,30 @@ pub fn load_mint(
     Ok(())
 }
 
+/// Errors if:
+/// - Owner is not SPL token program.
+/// - Data is empty.
+/// - Data cannot deserialize into a mint account.
+/// - Expected to be writable, but is not.
+#[cfg(feature = "spl")]
+pub fn load_any_mint(info: &AccountInfo<'_>, is_writable: bool) -> Result<(), ProgramError> {
+    if info.owner.ne(&spl_token::id()) {
+        return Err(ProgramError::InvalidAccountOwner);
+    }
+
+    if info.data_is_empty() {
+        return Err(ProgramError::UninitializedAccount);
+    }
+
+    Mint::unpack(&info.data.borrow())?;
+
+    if is_writable && !info.is_writable {
+        return Err(ProgramError::InvalidAccountData);
+    }
+
+    Ok(())
+}
+
 /// Errors if:
 /// - Owner is not SPL token program.
 /// - Data is empty.
@@ -187,3 +211,39 @@ pub fn load_token_account(
 
     Ok(())
 }
+
+/// Errors if:
+/// - Owner is not SPL token program.
+/// - Data is empty.
+/// - Data cannot deserialize into a token account.
+/// - Address does not match the expected associated token address.
+/// - Expected to be writable, but is not.
+#[cfg(feature = "spl")]
+pub fn load_associated_token_account(
+    info: &AccountInfo<'_>,
+    owner: &Pubkey,
+    mint: &Pubkey,
+    is_writable: bool,
+) -> Result<(), ProgramError> {
+    if info.owner.ne(&spl_token::id()) {
+        return Err(ProgramError::InvalidAccountOwner);
+    }
+
+    if info.data_is_empty() {
+        return Err(ProgramError::UninitializedAccount);
+    }
+
+    let account_data = info.data.borrow();
+    let _ = spl_token::state::Account::unpack(&account_data)?;
+
+    let address = spl_associated_token_account::get_associated_token_address(owner, mint);
+    if info.key.ne(&address) {
+        return Err(ProgramError::InvalidSeeds);
+    }
+
+    if is_writable && !info.is_writable {
+        return Err(ProgramError::InvalidAccountData);
+    }
+
+    Ok(())
+}

utils/src/macros.rs

@@ -98,8 +98,23 @@ macro_rules! event {
 
 #[macro_export]
 macro_rules! instruction {
-    ($struct_name:ident) => {
-        $crate::impl_to_bytes!($struct_name);
+    ($discriminator_name:ident, $struct_name:ident) => {
         $crate::impl_instruction_from_bytes!($struct_name);
+
+        impl $crate::Discriminator for $struct_name {
+            fn discriminator() -> u8 {
+                $discriminator_name::$struct_name as u8
+            }
+        }
+
+        impl $struct_name {
+            pub fn to_bytes(&self) -> Vec<u8> {
+                [
+                    [$discriminator_name::$struct_name as u8].to_vec(),
+                    bytemuck::bytes_of(self).to_vec(),
+                ]
+                .concat()
+            }
+        }
     };
 }

utils/src/traits.rs

@@ -1,10 +1,10 @@
 use solana_program::program_error::ProgramError;
 
-pub trait Discriminator {
-    fn discriminator() -> u8;
-}
-
 pub trait AccountDeserialize {
     fn try_from_bytes(data: &[u8]) -> Result<&Self, ProgramError>;
     fn try_from_bytes_mut(data: &mut [u8]) -> Result<&mut Self, ProgramError>;
 }
+
+pub trait Discriminator {
+    fn discriminator() -> u8;
+}