fix swap unit test

KomodoPlatform · Jan 14, 2025 · 450ced6 · 450ced6
1 parent 9059f93
commit 450ced6
Show file tree

Hide file tree

Showing 2 changed files with 21 additions and 10 deletions.
diff --git a/mm2src/mm2_main/src/lp_swap.rs b/mm2src/mm2_main/src/lp_swap.rs
@@ -800,6 +800,7 @@ fn dex_fee_rate(base: &str, rel: &str) -> MmNumber {
     } else {
         &["KMD"]
     };
+
     if fee_discount_tickers.contains(&base) || fee_discount_tickers.contains(&rel) {
         // 1/777 - 10%
         BigRational::new(9.into(), 7770.into()).into()
@@ -816,7 +817,6 @@ pub fn dex_fee_amount(base: &str, rel: &str, trade_amount: &MmNumber, min_tx_amo
 
     let rate = dex_fee_rate(base, rel);
     let fee = trade_amount * &rate;
-
     if &fee <= min_tx_amount {
         return DexFee::Standard(min_tx_amount.clone());
     }
@@ -2418,7 +2418,7 @@ mod lp_swap_tests {
         };
 
         let testcoin = coins::TestCoin::default();
- q       let testcoin_taker_fee = match dex_fee_amount_from_taker_coin(&testcoin, "", &MmNumber::from(6150)) {
+        let testcoin_taker_fee = match dex_fee_amount_from_taker_coin(&testcoin, "", &MmNumber::from(6150)) {
             DexFee::Standard(t) => t,
             DexFee::WithBurn { .. } | DexFee::Zero => {
                 panic!("Wrong variant returned for TEST coin from `dex_fee_amount_from_taker_coin`.")

diff --git a/mm2src/mm2_main/src/lp_swap/taker_swap.rs b/mm2src/mm2_main/src/lp_swap/taker_swap.rs
@@ -2735,12 +2735,16 @@ pub fn max_taker_vol_from_available(
     rel: &str,
     min_tx_amount: &MmNumber,
 ) -> Result<MmNumber, MmError<MaxTakerVolumeLessThanDust>> {
-    let dex_fee_rate = dex_fee_rate(base, rel);
-    let threshold_coef = &(&MmNumber::from(1) + &dex_fee_rate) / &dex_fee_rate;
-    let max_vol = if available > min_tx_amount * &threshold_coef {
-        available / (MmNumber::from(1) + dex_fee_rate)
-    } else {
+    let max_vol = if base == "KMD" || rel == "KMD" {
         &available - min_tx_amount
+    } else {
+        let dex_fee_rate = dex_fee_rate(base, rel);
+        let threshold_coef = &(&MmNumber::from(1) + &dex_fee_rate) / &dex_fee_rate;
+        if available > min_tx_amount * &threshold_coef {
+            available / (MmNumber::from(1) + dex_fee_rate)
+        } else {
+            &available - min_tx_amount
+        }
     };
 
     if &max_vol <= min_tx_amount {
@@ -3162,6 +3166,7 @@ mod taker_swap_tests {
         let min_tx_amount = MmNumber::from("0.00001");
 
         // For these `availables` the dex_fee must be greater than min_tx_amount
+        // For these `availables` the dex_fee must be lesser than min_tx_amount
         let source = vec![
             ("0.00779", false),
             ("0.01", false),
@@ -3186,7 +3191,8 @@ mod taker_swap_tests {
             assert_eq!(max_taker_vol + dex_fee, available);
         }
 
-        // for these `availables` the dex_fee must be the same as min_tx_amount
+        // KMD pairs: for these `availables` the dex_fee must be 0
+        // Non KMD pairs: for these `availables` the dex_fee must be the same as min_tx_amount
         let source = vec![
             ("0.00863333333333333333333333333333333333333333333333332", true),
             ("0.00863333333333333333333333333333333333333333333333331", true),
@@ -3207,9 +3213,14 @@ mod taker_swap_tests {
                 max_taker_vol.to_decimal(),
                 dex_fee.to_decimal()
             );
-            assert_eq!(min_tx_amount, dex_fee);
             assert!(min_tx_amount <= max_taker_vol);
-            assert_eq!(max_taker_vol + dex_fee, available);
+            if is_kmd {
+                assert_eq!(MmNumber::default(), dex_fee);
+                assert_eq!(&max_taker_vol + &min_tx_amount, available);
+            } else {
+                assert!(min_tx_amount <= max_taker_vol);
+                assert_eq!(max_taker_vol + dex_fee, available);
+            }
         }
 
         // these `availables` must return an error