swap tip consensus fix

src/verifications/async_funcs/verify_swap.rs

@@ -17,6 +17,23 @@ use crate::verifications::async_funcs::checks::verify_db::{
 use crate::wallets::structures::Wallet;
 use crate::Utc;
 
+fn validate_swap_tip(value: u64, tip: u64, is_nft: bool, sender: &str) -> Result<(), String> {
+    if is_nft {
+        if tip != 0 {
+            return Err(format!("Swap {sender} NFT tip must be zero."));
+        }
+        return Ok(());
+    }
+
+    let minimum_tip = value.div_ceil(100);
+    if tip < minimum_tip {
+        return Err(format!(
+            "Swap {sender} tip must be at least 1% of the offered amount."
+        ));
+    }
+    Ok(())
+}
+
 impl SwapTransaction {
     pub async fn verify(&self, db: &Db) -> Result<String, String> {
         // Transactions already present in the mempool can short-circuit
@@ -77,12 +94,13 @@ impl SwapTransaction {
             );
         }
         let network_base_coin_padded = block_extension_and_paths().1;
-        if !is_canonical_padded_asset_or_base(&self.unsigned_swap.ticker1, &network_base_coin_padded)
-            || !is_canonical_padded_asset_or_base(
+        if !is_canonical_padded_asset_or_base(
+            &self.unsigned_swap.ticker1,
+            &network_base_coin_padded,
+        ) || !is_canonical_padded_asset_or_base(
             &self.unsigned_swap.ticker2,
             &network_base_coin_padded,
-            )
-        {
+        ) {
             return Err(
                 "Swap assets must be the base coin or canonical alphanumeric asset ids."
                     .to_string(),
@@ -100,33 +118,43 @@ impl SwapTransaction {
 
         // Numbered NFT swaps are single-item transfers, while non-series
         // assets must already exist as a token, NFT, or base coin.
-        if self.unsigned_swap.nft_series1 > 0 {
+        let ticker1_is_nft = if self.unsigned_swap.nft_series1 > 0 {
             if self.unsigned_swap.value1 != 1 {
                 return Err("Series NFTs must swap exactly 1 item.".to_string());
             }
             if !db_bytes_verification(db, "nfts", &asset1).await {
                 return Err("Ticker1 NFT item does not exist.".to_string());
             }
-        } else if !(self.unsigned_swap.ticker1.trim().to_lowercase() == network_base_coin
-            || db_bytes_verification(db, "tokens", &self.unsigned_swap.ticker1).await
-            || db_bytes_verification(db, "nfts", &self.unsigned_swap.ticker1).await)
-        {
+            true
+        } else {
+            let is_base_coin =
+                self.unsigned_swap.ticker1.trim().to_lowercase() == network_base_coin;
+            let is_token = db_bytes_verification(db, "tokens", &self.unsigned_swap.ticker1).await;
+            let is_nft = db_bytes_verification(db, "nfts", &self.unsigned_swap.ticker1).await;
+            if !(is_base_coin || is_token || is_nft) {
                 return Err("Ticker1 does not exist.".to_string());
             }
+            is_nft
+        };
 
-        if self.unsigned_swap.nft_series2 > 0 {
+        let ticker2_is_nft = if self.unsigned_swap.nft_series2 > 0 {
             if self.unsigned_swap.value2 != 1 {
                 return Err("Series NFTs must swap exactly 1 item.".to_string());
             }
             if !db_bytes_verification(db, "nfts", &asset2).await {
                 return Err("Ticker2 NFT item does not exist.".to_string());
             }
-        } else if !(self.unsigned_swap.ticker2.trim().to_lowercase() == network_base_coin
-            || db_bytes_verification(db, "tokens", &self.unsigned_swap.ticker2).await
-            || db_bytes_verification(db, "nfts", &self.unsigned_swap.ticker2).await)
-        {
+            true
+        } else {
+            let is_base_coin =
+                self.unsigned_swap.ticker2.trim().to_lowercase() == network_base_coin;
+            let is_token = db_bytes_verification(db, "tokens", &self.unsigned_swap.ticker2).await;
+            let is_nft = db_bytes_verification(db, "nfts", &self.unsigned_swap.ticker2).await;
+            if !(is_base_coin || is_token || is_nft) {
                 return Err("Ticker2 does not exist.".to_string());
             }
+            is_nft
+        };
 
         // Each signer pays the fixed swap fee for their side of the trade.
         if self.unsigned_swap.txfee1 < SWAP_FEE {
@@ -141,6 +169,22 @@ impl SwapTransaction {
             ));
         }
 
+        // Fungible swap sides pay an asset-denominated miner tip of at
+        // least 1% of the offered amount. NFT sides cannot pay a
+        // fractional NFT tip, so their tip must be zero.
+        validate_swap_tip(
+            self.unsigned_swap.value1,
+            self.unsigned_swap.tip1,
+            ticker1_is_nft,
+            "sender1",
+        )?;
+        validate_swap_tip(
+            self.unsigned_swap.value2,
+            self.unsigned_swap.tip2,
+            ticker2_is_nft,
+            "sender2",
+        )?;
+
         // Each side must be able to cover the offered amount plus any
         // asset-denominated tip and the base-coin transaction fee.
         let full_value1 = self.unsigned_swap.value1 + self.unsigned_swap.tip1;
@@ -211,3 +255,21 @@ impl SwapTransaction {
         Ok(sign.to_string())
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::validate_swap_tip;
+
+    #[test]
+    fn fungible_swap_tip_requires_one_percent_rounded_up() {
+        assert!(validate_swap_tip(100, 1, false, "sender1").is_ok());
+        assert!(validate_swap_tip(101, 2, false, "sender1").is_ok());
+        assert!(validate_swap_tip(101, 1, false, "sender1").is_err());
+    }
+
+    #[test]
+    fn nft_swap_tip_must_be_zero() {
+        assert!(validate_swap_tip(1, 0, true, "sender1").is_ok());
+        assert!(validate_swap_tip(1, 1, true, "sender1").is_err());
+    }
+}