Simplification and doc comments

programs/voter-stake-registry/src/instructions/create_exchange_rate.rs

@@ -5,20 +5,22 @@ use anchor_spl::associated_token::AssociatedToken;
 use anchor_spl::token::{Mint, Token, TokenAccount};
 
 #[derive(Accounts)]
-#[instruction(idx: u16, mint: Pubkey, rate: u64, decimals: u8)]
+#[instruction(idx: u16, rate: u64, decimals: u8)]
 pub struct CreateExchangeRate<'info> {
     #[account(mut, has_one = realm_authority)]
     pub registrar: Box<Account<'info, Registrar>>,
     pub realm_authority: Signer<'info>,
 
+    /// Token account that all funds for this mint will be stored in
     #[account(
         init,
         payer = payer,
         associated_token::authority = registrar,
-        associated_token::mint = deposit_mint,
+        associated_token::mint = mint,
     )]
-    pub exchange_vault: Account<'info, TokenAccount>,
+    pub vault: Account<'info, TokenAccount>,
-    pub deposit_mint: Account<'info, Mint>,
+    /// Tokens of this mint will produce vote weight
+    pub mint: Account<'info, Mint>,
 
     #[account(mut)]
     pub payer: Signer<'info>,
@@ -30,15 +32,20 @@ pub struct CreateExchangeRate<'info> {
 }
 
 /// Creates a new exchange rate for a given mint. This allows a voter to
-/// deposit the mint in exchange for vTokens. There can only be a single
+/// deposit the mint in exchange for vote weight. There can only be a single
 /// exchange rate per mint.
 ///
-/// WARNING: This can be freely called when any of the rates are empty.
+/// `idx`: index of the rate to be set
-///          This should be called immediately upon creation of a Registrar.
+/// `rate`: multiplier to apply for converting tokens to vote weight
+/// `decimals`: number of decimals of mint that make one unit of token
+///
+/// The vote weight for one native token will be:
+/// ```
+/// rate * 10^vote_weight_decimals / 10^decimals
+/// ```
 pub fn create_exchange_rate(
     ctx: Context<CreateExchangeRate>,
     idx: u16,
-    mint: Pubkey,
     rate: u64,
     decimals: u8,
 ) -> Result<()> {
@@ -47,6 +54,6 @@ pub fn create_exchange_rate(
     let registrar = &mut ctx.accounts.registrar;
     require!((idx as usize) < registrar.rates.len(), InvalidIndex);
     require!(registrar.rates[idx as usize].rate == 0, RateNotZero);
-    registrar.rates[idx as usize] = registrar.new_rate(mint, decimals, rate)?;
+    registrar.rates[idx as usize] = registrar.new_rate(ctx.accounts.mint.key(), decimals, rate)?;
     Ok(())
 }

programs/voter-stake-registry/src/instructions/create_registrar.rs

@@ -8,7 +8,7 @@ use std::mem::size_of;
 #[derive(Accounts)]
 #[instruction(vote_weight_decimals: u8, registrar_bump: u8)]
 pub struct CreateRegistrar<'info> {
-    /// a voting registrar. There can only be a single registrar
+    /// The voting registrar. There can only be a single registrar
     /// per governance realm and governing mint.
     #[account(
         init,
@@ -19,16 +19,22 @@ pub struct CreateRegistrar<'info> {
     )]
     pub registrar: Box<Account<'info, Registrar>>,
 
-    // realm is validated in the instruction:
+    /// An spl-governance realm
-    // - realm is owned by the governance_program_id
+    ///
-    // - realm_governing_token_mint must be the community or council mint
+    /// realm is validated in the instruction:
-    // - realm_authority is realm.authority
+    /// - realm is owned by the governance_program_id
+    /// - realm_governing_token_mint must be the community or council mint
+    /// - realm_authority is realm.authority
     pub realm: UncheckedAccount<'info>,
 
+    /// The program id of the spl-governance program the realm belongs to.
     pub governance_program_id: UncheckedAccount<'info>,
+    /// Either the realm community mint or the council mint.
     pub realm_governing_token_mint: Account<'info, Mint>,
     pub realm_authority: Signer<'info>,
 
+    /// The authority that may use the clawback() instruction
+    // TODO: Just use the realm_authority?
     pub clawback_authority: UncheckedAccount<'info>,
 
     #[account(mut)]
@@ -39,8 +45,13 @@ pub struct CreateRegistrar<'info> {
     pub rent: Sysvar<'info, Rent>,
 }
 
-/// Creates a new voting registrar. There can only be a single registrar
+/// Creates a new voting registrar.
-/// per governance realm.
+///
+/// `vote_weight_decimals` is the number of decimals used on the vote weight. It must be
+/// larger or equal to all token mints used for voting.
+///
+/// To use the registrar, call CreateExchangeRate to register token mints that may be
+/// used for voting.
 pub fn create_registrar(
     ctx: Context<CreateRegistrar>,
     vote_weight_decimals: u8,

programs/voter-stake-registry/src/instructions/create_voter.rs

@@ -36,8 +36,6 @@ pub struct CreateVoter<'info> {
     #[account(mut)]
     pub payer: Signer<'info>,
 
-    pub token_program: Program<'info, Token>,
-    pub associated_token_program: Program<'info, AssociatedToken>,
     pub system_program: Program<'info, System>,
     pub rent: Sysvar<'info, Rent>,
 

programs/voter-stake-registry/src/instructions/deposit.rs

@@ -17,19 +17,18 @@ pub struct Deposit<'info> {
         associated_token::authority = registrar,
         associated_token::mint = deposit_mint,
     )]
-    pub exchange_vault: Box<Account<'info, TokenAccount>>,
+    pub vault: Box<Account<'info, TokenAccount>>,
     pub deposit_mint: Box<Account<'info, Mint>>,
-    #[account(mut)]
+
-    pub deposit_authority: Signer<'info>,
     #[account(
         mut,
         constraint = deposit_token.mint == deposit_mint.key(),
         constraint = deposit_token.owner == deposit_authority.key(),
     )]
     pub deposit_token: Box<Account<'info, TokenAccount>>,
+    pub deposit_authority: Signer<'info>,
 
     pub token_program: Program<'info, Token>,
-    pub associated_token_program: Program<'info, AssociatedToken>,
     pub system_program: Program<'info, System>,
     pub rent: Sysvar<'info, Rent>,
 }
@@ -39,7 +38,7 @@ impl<'info> Deposit<'info> {
         let program = self.token_program.to_account_info();
         let accounts = token::Transfer {
             from: self.deposit_token.to_account_info(),
-            to: self.exchange_vault.to_account_info(),
+            to: self.vault.to_account_info(),
             authority: self.deposit_authority.to_account_info(),
         };
         CpiContext::new(program, accounts)

programs/voter-stake-registry/src/instructions/withdraw.rs

@@ -28,7 +28,7 @@ pub struct WithdrawOrClawback<'info> {
         associated_token::authority = registrar,
         associated_token::mint = withdraw_mint,
     )]
-    pub exchange_vault: Box<Account<'info, TokenAccount>>,
+    pub vault: Box<Account<'info, TokenAccount>>,
     pub withdraw_mint: Box<Account<'info, Mint>>,
 
     #[account(mut)]
@@ -41,7 +41,7 @@ impl<'info> WithdrawOrClawback<'info> {
     pub fn transfer_ctx(&self) -> CpiContext<'_, '_, '_, 'info, token::Transfer<'info>> {
         let program = self.token_program.to_account_info();
         let accounts = token::Transfer {
-            from: self.exchange_vault.to_account_info(),
+            from: self.vault.to_account_info(),
             to: self.destination.to_account_info(),
             authority: self.registrar.to_account_info(),
         };

programs/voter-stake-registry/src/lib.rs

@@ -70,11 +70,10 @@ pub mod voter_stake_registry {
     pub fn create_exchange_rate(
         ctx: Context<CreateExchangeRate>,
         idx: u16,
-        mint: Pubkey,
         rate: u64,
         decimals: u8,
     ) -> Result<()> {
-        instructions::create_exchange_rate(ctx, idx, mint, rate, decimals)
+        instructions::create_exchange_rate(ctx, idx, rate, decimals)
     }
 
     pub fn create_voter(

programs/voter-stake-registry/tests/program_test/addin.rs

@@ -23,8 +23,8 @@ pub struct RegistrarCookie {
 
 #[derive(Clone, Copy)]
 pub struct ExchangeRateCookie {
-    pub deposit_mint: MintCookie,
+    pub mint: MintCookie,
-    pub exchange_vault: Pubkey,
+    pub vault: Pubkey,
 }
 
 pub struct VoterCookie {
@@ -107,7 +107,7 @@ impl AddinCookie {
         rate: u64,
     ) -> ExchangeRateCookie {
         let deposit_mint = mint.pubkey.unwrap();
-        let exchange_vault = spl_associated_token_account::get_associated_token_address(
+        let vault = spl_associated_token_account::get_associated_token_address(
             &registrar.address,
             &deposit_mint,
         );
@@ -115,7 +115,6 @@ impl AddinCookie {
         let data = anchor_lang::InstructionData::data(
             &voter_stake_registry::instruction::CreateExchangeRate {
                 idx: index,
-                mint: deposit_mint,
                 rate,
                 decimals: mint.decimals,
             },
@@ -123,8 +122,8 @@ impl AddinCookie {
 
         let accounts = anchor_lang::ToAccountMetas::to_account_metas(
             &voter_stake_registry::accounts::CreateExchangeRate {
-                exchange_vault,
+                vault,
-                deposit_mint,
+                mint: deposit_mint,
                 registrar: registrar.address,
                 realm_authority: authority.pubkey(),
                 payer: payer.pubkey(),
@@ -152,8 +151,8 @@ impl AddinCookie {
             .unwrap();
 
         ExchangeRateCookie {
-            deposit_mint: mint.clone(),
+            mint: mint.clone(),
-            exchange_vault,
+            vault,
         }
     }
 
@@ -193,8 +192,6 @@ impl AddinCookie {
                 registrar: registrar.address,
                 voter_authority: authority.pubkey(),
                 payer: payer.pubkey(),
-                token_program: spl_token::id(),
-                associated_token_program: spl_associated_token_account::id(),
                 system_program: solana_sdk::system_program::id(),
                 rent: solana_program::sysvar::rent::id(),
                 instructions: solana_program::sysvar::instructions::id(),
@@ -247,7 +244,7 @@ impl AddinCookie {
                 registrar: registrar.address,
                 voter: voter.address,
                 voter_authority: voter_authority.pubkey(),
-                deposit_mint: exchange_rate.deposit_mint.pubkey.unwrap(),
+                deposit_mint: exchange_rate.mint.pubkey.unwrap(),
             },
             None,
         );
@@ -286,12 +283,11 @@ impl AddinCookie {
             &voter_stake_registry::accounts::Deposit {
                 registrar: registrar.address,
                 voter: voter.address,
-                exchange_vault: exchange_rate.exchange_vault,
+                vault: exchange_rate.vault,
                 deposit_token: token_address,
                 deposit_authority: authority.pubkey(),
-                deposit_mint: exchange_rate.deposit_mint.pubkey.unwrap(),
+                deposit_mint: exchange_rate.mint.pubkey.unwrap(),
                 token_program: spl_token::id(),
-                associated_token_program: spl_associated_token_account::id(),
                 system_program: solana_sdk::system_program::id(),
                 rent: solana_program::sysvar::rent::id(),
             },
@@ -333,8 +329,8 @@ impl AddinCookie {
                 registrar: registrar.address,
                 voter: voter.address,
                 token_owner_record: token_owner_record.address,
-                exchange_vault: exchange_rate.exchange_vault,
+                vault: exchange_rate.vault,
-                withdraw_mint: exchange_rate.deposit_mint.pubkey.unwrap(),
+                withdraw_mint: exchange_rate.mint.pubkey.unwrap(),
                 destination: token_address,
                 authority: clawback_authority.pubkey(),
                 token_program: spl_token::id(),
@@ -378,8 +374,8 @@ impl AddinCookie {
                 registrar: registrar.address,
                 voter: voter.address,
                 token_owner_record: token_owner_record.address,
-                exchange_vault: exchange_rate.exchange_vault,
+                vault: exchange_rate.vault,
-                withdraw_mint: exchange_rate.deposit_mint.pubkey.unwrap(),
+                withdraw_mint: exchange_rate.mint.pubkey.unwrap(),
                 destination: token_address,
                 authority: authority.pubkey(),
                 token_program: spl_token::id(),
@@ -508,10 +504,7 @@ impl AddinCookie {
 
 impl ExchangeRateCookie {
     pub async fn vault_balance(&self, solana: &SolanaCookie) -> u64 {
-        solana
+        solana.get_account::<TokenAccount>(self.vault).await.amount
-            .get_account::<TokenAccount>(self.exchange_vault)
-            .await
-            .amount
     }
 }