save dev state

mm2src/coins/eth.rs

@@ -5896,7 +5896,7 @@ impl MmCoin for EthCoin {
             EthCoinType::Erc20 { platform, .. } => platform.to_owned(),
             EthCoinType::Nft { .. } => return MmError::err(TradePreimageError::NftProtocolNotSupported),
         };
-        if DexFee::Zero == dex_fee_amount {
+        if dex_fee_amount.no_fee() {
             return Ok(TradeFee {
                 coin: fee_coin,
                 amount: MmNumber::default(),

mm2src/coins/lp_coins.rs

@@ -3680,6 +3680,9 @@ impl DexFee {
             Ok(None)
         }
     }
+
+    /// Check and return true if DexFee is not required to trade otherwise return false.
+    pub fn no_fee(&self) -> bool { matches!(self, Self::Zero) }
 }
 
 pub struct CoinsContext {

mm2src/coins/qrc20.rs

@@ -1418,7 +1418,7 @@ impl MmCoin for Qrc20Coin {
         dex_fee_amount: DexFee,
         stage: FeeApproxStage,
     ) -> TradePreimageResult<TradeFee> {
-        if DexFee::Zero == dex_fee_amount {
+        if dex_fee_amount.no_fee() {
             return Ok(TradeFee {
                 coin: self.platform.clone(),
                 amount: MmNumber::default(),

mm2src/coins/tendermint/tendermint_coin.rs

@@ -2478,7 +2478,7 @@ impl MmCoin for TendermintCoin {
         dex_fee_amount: DexFee,
         _stage: FeeApproxStage,
     ) -> TradePreimageResult<TradeFee> {
-        if DexFee::Zero == dex_fee_amount {
+        if dex_fee_amount.no_fee() {
             return Ok(TradeFee {
                 coin: self.ticker.clone(),
                 amount: MmNumber::default(),

mm2src/coins/utxo/slp.rs

@@ -1844,7 +1844,7 @@ impl MmCoin for SlpToken {
         dex_fee_amount: DexFee,
         stage: FeeApproxStage,
     ) -> TradePreimageResult<TradeFee> {
-        if DexFee::Zero == dex_fee_amount {
+        if dex_fee_amount.no_fee() {
             return Ok(TradeFee {
                 coin: self.platform_coin.ticker().into(),
                 amount: MmNumber::default(),

mm2src/coins/utxo/utxo_common.rs

@@ -1498,7 +1498,7 @@ fn generate_taker_fee_tx_outputs(
     dex_fee: &DexFee,
 ) -> Result<Vec<TransactionOutput>, MmError<NumConversError>> {
     // Don't add outputs for Zero DexFee.
-    if let DexFee::Zero = dex_fee {
+    if dex_fee.no_fee() {
         return Ok(vec![]);
     }
 
@@ -3989,7 +3989,7 @@ pub async fn get_fee_to_send_taker_fee<T>(
 where
     T: MarketCoinOps + UtxoCommonOps,
 {
-    if DexFee::Zero == dex_fee {
+    if dex_fee.no_fee() {
         return Ok(TradeFee {
             coin: coin.ticker().to_owned(),
             amount: MmNumber::default(),

mm2src/coins/z_coin.rs

@@ -1753,7 +1753,7 @@ impl MmCoin for ZCoin {
         dex_fee_amount: DexFee,
         _stage: FeeApproxStage,
     ) -> TradePreimageResult<TradeFee> {
-        if DexFee::Zero == dex_fee_amount {
+        if dex_fee_amount.no_fee() {
             return Ok(TradeFee {
                 coin: self.ticker().to_owned(),
                 amount: MmNumber::default(),

mm2src/mm2_main/src/lp_swap.rs

@@ -969,7 +969,7 @@ impl SwapTxDataMsg {
     }
 }
 
-#[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
+#[derive(Clone, Debug, Default, Deserialize, PartialEq, Serialize)]
 pub struct TransactionIdentifier {
     /// Raw bytes of signed transaction in hexadecimal string, this should be sent as is to send_raw_transaction RPC to broadcast the transaction.
     /// Some payments like lightning payments don't have a tx_hex, for such payments tx_hex will be equal to tx_hash.

mm2src/mm2_main/src/lp_swap/maker_swap.rs

@@ -742,13 +742,9 @@ impl MakerSwap {
         let taker_amount = MmNumber::from(self.taker_amount.clone());
         let dex_fee = dex_fee_amount_from_taker_coin(self.taker_coin.deref(), &self.r().data.maker_coin, &taker_amount);
 
-        if coins::DexFee::Zero == dex_fee {
+        if dex_fee.no_fee() {
             info!("Zero Dex Fee: Skipping taker fee");
-            let fee_ident = TransactionIdentifier {
-                tx_hex: BytesJson::from(vec![]),
-                tx_hash: BytesJson::from(vec![]),
-            };
-            swap_events.push(MakerSwapEvent::TakerFeeValidated(fee_ident));
+            swap_events.push(MakerSwapEvent::TakerFeeValidated(TransactionIdentifier::default()));
             return Ok((Some(MakerSwapCommand::SendPayment), swap_events));
         }
 

mm2src/mm2_main/src/lp_swap/taker_swap.rs

@@ -1304,6 +1304,13 @@ impl TakerSwap {
 
         let fee_amount =
             dex_fee_amount_from_taker_coin(self.taker_coin.deref(), &self.r().data.maker_coin, &self.taker_amount);
+        if fee_amount.no_fee() {
+            debug!("zero-dex-fee: skipping send taker fee");
+            return Ok((Some(TakerSwapCommand::WaitForMakerPayment), vec![
+                TakerSwapEvent::TakerFeeSent(TransactionIdentifier::default()),
+            ]));
+        }
+
         let fee_tx = self
             .taker_coin
             .send_taker_fee(&DEX_FEE_ADDR_RAW_PUBKEY, fee_amount, self.uuid.as_bytes(), expire_at)