remove max spread check for stableswap pool (#91)

dexter-zone · Apr 29, 2024 · 05a52c5 · 05a52c5
2 parents ead2662 + d91162d
commit 05a52c5
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Showing 5 changed files with 45 additions and 75 deletions.
diff --git a/contracts/pools/stable_pool/src/contract.rs b/contracts/pools/stable_pool/src/contract.rs
@@ -509,17 +509,16 @@ pub fn query(deps: Deps, env: Env, msg: QueryMsg) -> StdResult<Binary> {
             offer_asset,
             ask_asset,
             amount,
-            max_spread,
-            belief_price,
+            max_spread: _,
+            belief_price: _,
         } => to_json_binary(&query_on_swap(
             deps,
             env,
             swap_type,
             offer_asset,
             ask_asset,
             amount,
-            max_spread,
-            belief_price,
+
         )?),
         QueryMsg::CumulativePrice {
             offer_asset,
@@ -934,8 +933,6 @@ pub fn query_on_swap(
     offer_asset_info: AssetInfo,
     ask_asset_info: AssetInfo,
     amount: Uint128,
-    max_spread: Option<Decimal>,
-    belief_price: Option<Decimal>,
 ) -> StdResult<SwapResponse> {
     // Load the config and math config from the storage
     let config: Config = CONFIG.load(deps.storage)?;
@@ -970,7 +967,7 @@ pub fn query_on_swap(
 
     let offer_asset: Asset;
     let ask_asset: Asset;
-    let (calc_amount, spread_amount): (Uint128, Uint128);
+    let calc_amount: Uint128;
     let total_fee: Uint128;
 
     let ask_asset_scaling_factor = scaling_factors
@@ -1001,7 +998,7 @@ pub fn query_on_swap(
             .to_scaled_decimal_asset(offer_precision, offer_asset_scaling_factor)?;
 
             // Calculate the number of ask_asset tokens to be transferred to the recipient from the Vault contract
-            (calc_amount, spread_amount) = match compute_swap(
+            calc_amount = match compute_swap(
                 deps.storage,
                 &env,
                 &math_config,
@@ -1038,7 +1035,7 @@ pub fn query_on_swap(
             .to_scaled_decimal_asset(ask_precision, ask_asset_scaling_factor)?;
 
             // Calculate the number of offer_asset tokens to be transferred from the trader from the Vault contract
-            (calc_amount, spread_amount, total_fee) = match compute_offer_amount(
+            (calc_amount, total_fee) = match compute_offer_amount(
                 deps.storage,
                 &env,
                 &math_config,
@@ -1077,24 +1074,11 @@ pub fn query_on_swap(
         ));
     }
 
-    // Check the max spread limit (if it was specified)
-    let spread_check = assert_max_spread(
-        stableswap_config.max_allowed_spread,
-        belief_price,
-        max_spread,
-        offer_asset.amount - total_fee,
-        ask_asset.amount,
-        spread_amount,
-    );
-    if !spread_check.is_success() {
-        return Ok(return_swap_failure(spread_check.to_string()));
-    }
-
     Ok(SwapResponse {
         trade_params: Trade {
             amount_in: offer_asset.amount,
             amount_out: ask_asset.amount,
-            spread: spread_amount,
+            spread: Uint128::zero(),
         },
         response: ResponseType::Success {},
         fee: Some(Asset {

diff --git a/contracts/pools/stable_pool/src/utils.rs b/contracts/pools/stable_pool/src/utils.rs
@@ -31,7 +31,7 @@ pub(crate) fn compute_swap(
     ask_pool: &DecimalAsset,
     pools: &[DecimalAsset],
     ask_asset_scaling_factor: Decimal256,
-) -> StdResult<(Uint128, Uint128)> {
+) -> StdResult<Uint128> {
     // get ask asset precision
     let ask_asset_precision = get_precision(storage, &ask_pool.info)?;
 
@@ -49,19 +49,7 @@ pub(crate) fn compute_swap(
         .without_scaling_factor(ask_asset_scaling_factor)?
         .to_uint128_with_precision(ask_asset_precision)?;
 
-    let offer_asset_amount = offer_asset
-        .amount
-        .to_uint128_with_precision(ask_asset_precision)?;
-
-    // We consider swap rate 1:1 in stable swap thus any difference is considered as spread.
-    let spread_amount = offer_asset_amount.saturating_sub(return_amount);
-
-    // Spread amount must be scaled by the scaling factor of the ask asset to get the actual spread amount in the ask asset terms.
-    let spread_amount_without_scaling_factor = Decimal256::with_precision(spread_amount, ask_asset_precision as u32)?
-        .without_scaling_factor(ask_asset_scaling_factor)?
-        .to_uint128_with_precision(ask_asset_precision)?;
-
-    Ok((return_amount_without_scaling_factor, spread_amount_without_scaling_factor))
+    Ok(return_amount_without_scaling_factor)
 }
 
 /// ## Description
@@ -82,11 +70,10 @@ pub(crate) fn compute_offer_amount(
     ask_pool: &DecimalAsset,
     pools: &[DecimalAsset],
     commission_rate: u16,
-    ask_asset_scaling_factor: Decimal256,
+    _ask_asset_scaling_factor: Decimal256,
     offer_asset_scaling_factor: Decimal256,
-) -> StdResult<(Uint128, Uint128, Uint128)> {
+) -> StdResult<(Uint128, Uint128)> {
     let offer_precision = get_precision(storage, &offer_pool.info)?;
-    let ask_precision = get_precision(storage, &ask_asset.info)?;
 
     let one_minus_commission = Decimal256::one()
         - decimal2decimal256(Decimal::from_ratio(commission_rate, FEE_PRECISION))?;
@@ -121,16 +108,7 @@ pub(crate) fn compute_offer_amount(
     let fee = offer_amount_including_fee - offer_amount_without_scaling_factor;
     let fee_uint128 = fee.to_uint128_with_precision(offer_precision)?;
 
-    // We assume the assets should stay in a 1:1 ratio, so the true exchange rate is 1. Any exchange rate < 1 could be considered the spread
-    let ask_asset_with_scaling_factor_gp = ask_asset.amount.to_uint128_with_precision(Decimal256::DECIMAL_PLACES)?;
-    let offer_amount_with_scaling_factor_excluding_fee_gp = offer_amount_with_scaling_factor_gp;
-    let spread_amount_gp = offer_amount_with_scaling_factor_excluding_fee_gp.saturating_sub(ask_asset_with_scaling_factor_gp);
-
-    let spread_amount_without_scaling_factor = Decimal256::with_precision(spread_amount_gp, Decimal256::DECIMAL_PLACES as u32)?
-        .without_scaling_factor(ask_asset_scaling_factor)?
-        .to_uint128_with_precision(ask_precision)?;
-
-    Ok((offer_amount_including_fee_uint128, spread_amount_without_scaling_factor, fee_uint128))
+    Ok((offer_amount_including_fee_uint128, fee_uint128))
 }
 
 // --------x--------x--------x--------x--------x--------x--------
@@ -216,7 +194,7 @@ pub fn accumulate_prices(
         let offer_asset_scaled = offer_asset.with_scaling_factor(offer_asset_scaling_factor)?;
 
         let (offer_pool, ask_pool) = select_pools(from, to, pools).unwrap();
-        let (return_amount, _) = compute_swap(
+        let return_amount = compute_swap(
             deps.storage,
             &env,
             &math_config,

diff --git a/contracts/pools/stable_pool/tests/integration.rs b/contracts/pools/stable_pool/tests/integration.rs
@@ -2,7 +2,7 @@ use cosmwasm_std::{from_json, to_json_binary, Addr, Coin, Decimal, Timestamp, Ui
 use cw20::{BalanceResponse, Cw20ExecuteMsg, Cw20QueryMsg};
 use cw_multi_test::Executor;
 
-use dexter::asset::{Asset, AssetExchangeRate, AssetInfo};
+use dexter::asset::{native_asset_info, Asset, AssetExchangeRate, AssetInfo};
 use dexter::pool::{AfterExitResponse, AfterJoinResponse, ConfigResponse, CumulativePricesResponse, ExecuteMsg, ExitType, QueryMsg, ResponseType, SwapResponse};
 use dexter::vault;
 use dexter::vault::{
@@ -1896,7 +1896,7 @@ fn test_swap() {
     );
     assert_eq!(
         swap_offer_asset_res.trade_params.spread,
-        Uint128::from(5u128)
+        Uint128::from(0u128)
     );
     assert_eq!(
         swap_offer_asset_res.fee.clone().unwrap().info,
@@ -1965,7 +1965,7 @@ fn test_swap() {
     );
     assert_eq!(
         swap_offer_asset_res.trade_params.spread,
-        Uint128::from(5341176u128)
+        Uint128::from(0u128)
     );
     assert_eq!(
         swap_offer_asset_res.fee.clone().unwrap().info,
@@ -1998,25 +1998,30 @@ fn test_swap() {
             },
         )
         .unwrap();
+
+    // Success: since the max_spread field is ignored
     assert_eq!(
         swap_offer_asset_res.response,
-        ResponseType::Failure(
-            "error : Operation exceeds max spread limit. Current spread = 0.066984666048109965".to_string()
-        )
+        ResponseType::Success {}
     );
     assert_eq!(
         swap_offer_asset_res.trade_params.amount_in,
-        Uint128::from(0u128)
+        Uint128::from(30000_000000u128)
     );
     assert_eq!(
         swap_offer_asset_res.trade_params.amount_out,
-        Uint128::from(0u128)
+        Uint128::from(27150_746218u128)
     );
     assert_eq!(
         swap_offer_asset_res.trade_params.spread,
         Uint128::from(0u128)
     );
-    assert_eq!(swap_offer_asset_res.fee.clone(), None);
+    assert_eq!(swap_offer_asset_res.fee.clone(), Some(Asset {
+        info: AssetInfo::NativeToken {
+            denom: "axlusd".to_string()
+        },
+        amount: Uint128::from(900_000000u128)
+    }));
 
     // SwapType::GiveOut {},
     let swap_offer_asset_res: SwapResponse = app
@@ -2037,26 +2042,27 @@ fn test_swap() {
             },
         )
         .unwrap();
+    // Success: since we removed the check
     assert_eq!(
         swap_offer_asset_res.response,
-        ResponseType::Failure(
-            "error : Operation exceeds max spread limit. Current spread = 0.187679712517183249"
-                .to_string()
-        )
+        ResponseType::Success {  }
     );
     assert_eq!(
         swap_offer_asset_res.trade_params.amount_in,
-        Uint128::from(0u128)
+        Uint128::from(63455_748363u128)
     );
     assert_eq!(
         swap_offer_asset_res.trade_params.amount_out,
-        Uint128::from(0u128)
+        Uint128::from(50000_000000u128)
     );
     assert_eq!(
         swap_offer_asset_res.trade_params.spread,
         Uint128::from(0u128)
     );
-    assert_eq!(swap_offer_asset_res.fee.clone(), None);
+    assert_eq!(swap_offer_asset_res.fee.clone(), Some(Asset {
+        info: native_asset_info("axlusd".to_string()),
+        amount: Uint128::from(1903_672450u128)
+    }));
 
     //// -----x----- Check #3 :: EXECUTE Success :::  -----x----- ////
 

diff --git a/contracts/pools/stable_pool/tests/test_scaling_factor.rs b/contracts/pools/stable_pool/tests/test_scaling_factor.rs
@@ -377,7 +377,7 @@ fn test_swap() {
         },
         Some(Decimal::from_ratio(20u64, 100u64)),
         Uint128::from(1_017_336_487u128),
-        Uint128::from(10_451u128),
+        Uint128::from(0u128),
         Asset {
             info: AssetInfo::NativeToken {
                 denom: "ustkatom".to_string(),
@@ -405,7 +405,7 @@ fn test_swap() {
         },
         Some(Decimal::from_ratio(20u64, 100u64)),
         Uint128::from(982_978_603u128),
-        Uint128::from(30_273u128),
+        Uint128::from(0u128),
         Asset {
             info: AssetInfo::NativeToken {
                 denom: "ustkatom".to_string(),
@@ -533,7 +533,7 @@ fn test_swap_different_precision() {
         },
         Some(Decimal::from_ratio(20u64, 100u64)),
         Uint128::from(1_017_336_487u128),
-        Uint128::from(10_451u128),
+        Uint128::from(0u128),
         Asset {
             info: AssetInfo::NativeToken {
                 denom: "ustkatom".to_string(),
@@ -561,7 +561,7 @@ fn test_swap_different_precision() {
         },
         Some(Decimal::from_ratio(20u64, 100u64)),
         Uint128::from(982_978_603_388u128),
-        Uint128::from(30_273u128),
+        Uint128::from(0u128),
         Asset {
             info: AssetInfo::NativeToken {
                 denom: "ustkatom".to_string(),
@@ -755,7 +755,7 @@ fn test_swap_different_lsd_assets() {
         },
         Some(Decimal::from_ratio(20u64, 100u64)),
         Uint128::from(976_643_026u128),
-        Uint128::from(10_033u128),
+        Uint128::from(0u128),
         Asset {
             info: AssetInfo::NativeToken {
                 denom: "ustkatom".to_string(),
@@ -805,7 +805,7 @@ fn test_swap_different_lsd_assets() {
         },
         Some(Decimal::from_ratio(20u64, 100u64)),
         Uint128::from(1_023_936_467_628u128),
-        Uint128::from(30_685u128),
+        Uint128::from(0u128),
         Asset {
             info: AssetInfo::NativeToken {
                 denom: "ustkatom".to_string(),
@@ -984,7 +984,7 @@ fn test_5_asset_lsd_pool_with_different_precisions() {
         atom_asset.clone(),
         Some(Decimal::from_ratio(20u64, 100u64)),
         Uint128::from(1_038_125u128),
-        Uint128::from(416u128),
+        Uint128::from(0u128),
         Asset {
             info: statom_asset.clone(),
             amount: Uint128::from(3_000u128),
@@ -1009,7 +1009,7 @@ fn test_5_asset_lsd_pool_with_different_precisions() {
         qatom_asset.clone(),
         Some(Decimal::from_ratio(20u64, 100u64)),
         Uint128::from(10_277_441_665_935_813u128),
-        Uint128::from(4_120_834_064_186u128),
+        Uint128::from(0u128),
         Asset {
             info: statom_asset.clone(),
             amount: Uint128::from(30_000_000u128),

diff --git a/packages/dexter/src/pool.rs b/packages/dexter/src/pool.rs
@@ -169,7 +169,9 @@ pub enum QueryMsg {
         offer_asset: AssetInfo,
         ask_asset: AssetInfo,
         amount: Uint128,
+        // DEPRECATED: not used in any pool type. use min received for slippage protection
         max_spread: Option<Decimal>,
+        // DEPRECATED: not used in any pool type. use min received for slippage protection
         belief_price: Option<Decimal>,
     },
     /// ## Description - Returns information about the cumulative price of the asset in a [`CumulativePriceResponse`] object.