token-swap: Add version to state (#985)

* Add version to token swap state

* Fix fuzz

* Cargo fmt

* Revert solana localnet version

* Update enum dispatch

Author: joncinque

Cargo.lock

@@ -58,6 +58,7 @@ export class Numberu64 extends BN {
  */
 export const TokenSwapLayout: typeof BufferLayout.Structure = BufferLayout.struct(
   [
+    BufferLayout.u8('version'),
     BufferLayout.u8('isInitialized'),
     BufferLayout.u8('nonce'),
     Layout.publicKey('tokenProgramId'),

token-swap/js/client/token-swap.js

@@ -14,6 +14,7 @@ fuzz = ["arbitrary"]
 
 [dependencies]
 arrayref = "0.3.6"
+enum_dispatch = "0.3.4"
 num-derive = "0.3"
 num-traits = "0.2"
 solana-program = "1.5.1"

token-swap/program/Cargo.toml

@@ -10,14 +10,12 @@ use spl_token_swap::{
         self, DepositAllTokenTypes, DepositSingleTokenTypeExactAmountIn, Swap,
         WithdrawAllTokenTypes, WithdrawSingleTokenTypeExactAmountOut,
     },
-    state::SwapInfo,
+    state::SwapVersion,
 };
 
 use spl_token::instruction::approve;
 
-use solana_program::{
-    bpf_loader, entrypoint::ProgramResult, program_pack::Pack, pubkey::Pubkey, system_program,
-};
+use solana_program::{bpf_loader, entrypoint::ProgramResult, pubkey::Pubkey, system_program};
 
 pub struct NativeTokenSwap {
     pub user_account: NativeAccountData,
@@ -51,7 +49,8 @@ impl NativeTokenSwap {
     ) -> Self {
         let mut user_account = NativeAccountData::new(0, system_program::id());
         user_account.is_signer = true;
-        let mut swap_account = NativeAccountData::new(SwapInfo::LEN, spl_token_swap::id());
+        let mut swap_account =
+            NativeAccountData::new(SwapVersion::LATEST_LEN, spl_token_swap::id());
         let (authority_key, nonce) = Pubkey::find_program_address(
             &[&swap_account.key.to_bytes()[..]],
             &spl_token_swap::id(),

token-swap/program/fuzz/src/native_token_swap.rs

@@ -92,11 +92,11 @@ pub struct WithdrawSingleTokenTypeExactAmountOut {
     pub maximum_pool_token_amount: u64,
 }
 
-/// Instructions supported by the SwapInfo program.
+/// Instructions supported by the token swap program.
 #[repr(C)]
 #[derive(Debug, PartialEq)]
 pub enum SwapInstruction {
-    ///   Initializes a new SwapInfo.
+    ///   Initializes a new swap
     ///
     ///   0. `[writable, signer]` New Token-swap to create.
     ///   1. `[]` swap authority derived from `create_program_address(&[Token-swap account])`