feat(fee_share): implement swap fee sharing on all pool types (#90)

* feat(fee_share): Implement fee sharing in swap
* feat(fee_share): Implement fee sharing for stableswap
* feat(fee_share): Emit shared amount in swap response
* feat(fee_share): Implement fee sharing for PCL
* fix(fee_sharing): Bump PCL version
* fix(fee_share): Output full correct amount
* fix(fee_share): Bump versions of pairs
* fix(fee_share): Bump migration version
* fix(fee_share): Bump cosmwasm-check to 1.4.0

.github/workflows/check_artifacts.yml

@@ -112,7 +112,7 @@ jobs:
           fail-on-cache-miss: true
       - name: Install cosmwasm-check
         # Uses --debug for compilation speed
-        run: cargo install --debug --version 1.3.1 cosmwasm-check
+        run: cargo install --debug --version 1.4.0 cosmwasm-check
       - name: Cosmwasm check
         run: |
           cosmwasm-check $GITHUB_WORKSPACE/artifacts/*.wasm --available-capabilities staking,cosmwasm_1_1,injective,iterator,stargate

contracts/pair/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "astroport-pair"
-version = "1.4.0"
+version = "1.5.0"
 authors = ["Astroport"]
 edition = "2021"
 description = "The Astroport constant product pool contract implementation"

contracts/pair/src/contract.rs

@@ -19,8 +19,8 @@ use astroport::asset::{
 use astroport::factory::PairType;
 use astroport::generator::Cw20HookMsg as GeneratorHookMsg;
 use astroport::pair::{
-    ConfigResponse, XYKPoolConfig, XYKPoolParams, XYKPoolUpdateParams, DEFAULT_SLIPPAGE,
-    MAX_ALLOWED_SLIPPAGE,
+    ConfigResponse, FeeShareConfig, XYKPoolConfig, XYKPoolParams, XYKPoolUpdateParams,
+    DEFAULT_SLIPPAGE, MAX_ALLOWED_SLIPPAGE, MAX_FEE_SHARE_BPS,
 };
 use astroport::pair::{
     CumulativePricesResponse, Cw20HookMsg, ExecuteMsg, InstantiateMsg, MigrateMsg, PoolResponse,
@@ -80,6 +80,7 @@ pub fn instantiate(
         price0_cumulative_last: Uint128::zero(),
         price1_cumulative_last: Uint128::zero(),
         track_asset_balances,
+        fee_share: None,
     };
 
     if track_asset_balances {
@@ -691,12 +692,39 @@ pub fn swap(
         messages.push(return_asset.into_msg(receiver.clone())?)
     }
 
+    // If this pool is configured to share fees, calculate the amount to send
+    // to the receiver and add the transfer message
+    // The calculation works as follows: We take the share percentage first,
+    // and the remainder is then split between LPs and maker
+    let mut fees_commission_amount = commission_amount;
+    let mut fee_share_amount = Uint128::zero();
+    if let Some(fee_share) = config.fee_share.clone() {
+        // Calculate the fee share amount from the full commission amount
+        let share_fee_rate = Decimal::from_ratio(fee_share.bps, 10000u16);
+        fee_share_amount = fees_commission_amount * share_fee_rate;
+
+        if !fee_share_amount.is_zero() {
+            // Subtract the fee share amount from the commission
+            fees_commission_amount = fees_commission_amount.saturating_sub(fee_share_amount);
+
+            // Build send message for the shared amount
+            let fee_share_msg = Asset {
+                info: ask_pool.info.clone(),
+                amount: fee_share_amount,
+            }
+            .into_msg(fee_share.recipient)?;
+            messages.push(fee_share_msg);
+        }
+    }
+
     // Compute the Maker fee
     let mut maker_fee_amount = Uint128::zero();
     if let Some(fee_address) = fee_info.fee_address {
-        if let Some(f) =
-            calculate_maker_fee(&ask_pool.info, commission_amount, fee_info.maker_fee_rate)
-        {
+        if let Some(f) = calculate_maker_fee(
+            &ask_pool.info,
+            fees_commission_amount,
+            fee_info.maker_fee_rate,
+        ) {
             maker_fee_amount = f.amount;
             messages.push(f.into_msg(fee_address)?);
         }
@@ -712,7 +740,7 @@ pub fn swap(
         BALANCES.save(
             deps.storage,
             &ask_pool.info,
-            &(ask_pool.amount - return_amount - maker_fee_amount),
+            &(ask_pool.amount - return_amount - maker_fee_amount - fee_share_amount),
             env.block.height,
         )?;
     }
@@ -744,6 +772,7 @@ pub fn swap(
             attr("spread_amount", spread_amount),
             attr("commission_amount", commission_amount),
             attr("maker_fee_amount", maker_fee_amount),
+            attr("fee_share_amount", fee_share_amount),
         ]))
 }
 
@@ -787,6 +816,44 @@ pub fn update_config(
                 "enabled".to_owned(),
             ));
         }
+        XYKPoolUpdateParams::EnableFeeShare {
+            fee_share_bps,
+            fee_share_address,
+        } => {
+            // Enable fee sharing for this contract
+            // If fee sharing is already enabled, we should be able to overwrite
+            // the values currently set
+
+            // Ensure the fee share isn't 0 and doesn't exceed the maximum allowed value
+            if fee_share_bps == 0 || fee_share_bps > MAX_FEE_SHARE_BPS {
+                return Err(ContractError::FeeShareOutOfBounds {});
+            }
+
+            // Set sharing config
+            config.fee_share = Some(FeeShareConfig {
+                bps: fee_share_bps,
+                recipient: deps.api.addr_validate(&fee_share_address)?,
+            });
+
+            CONFIG.save(deps.storage, &config)?;
+
+            response.attributes.push(attr("action", "enable_fee_share"));
+            response
+                .attributes
+                .push(attr("fee_share_bps", fee_share_bps.to_string()));
+            response
+                .attributes
+                .push(attr("fee_share_address", fee_share_address));
+        }
+        XYKPoolUpdateParams::DisableFeeShare => {
+            // Disable fee sharing for this contract by setting bps and
+            // address back to None
+            config.fee_share = None;
+            CONFIG.save(deps.storage, &config)?;
+            response
+                .attributes
+                .push(attr("action", "disable_fee_share"));
+        }
     }
 
     Ok(response)
@@ -1069,6 +1136,7 @@ pub fn query_config(deps: Deps) -> StdResult<ConfigResponse> {
         block_time_last: config.block_time_last,
         params: Some(to_binary(&XYKPoolConfig {
             track_asset_balances: config.track_asset_balances,
+            fee_share: config.fee_share,
         })?),
         owner: factory_config.owner,
         factory_addr: config.factory_addr,

contracts/pair/src/error.rs

@@ -1,4 +1,4 @@
-use astroport::asset::MINIMUM_LIQUIDITY_AMOUNT;
+use astroport::{asset::MINIMUM_LIQUIDITY_AMOUNT, pair::MAX_FEE_SHARE_BPS};
 use cosmwasm_std::{OverflowError, StdError};
 use thiserror::Error;
 
@@ -52,6 +52,12 @@ pub enum ContractError {
 
     #[error("Failed to parse or process reply message")]
     FailedToParseReply {},
+
+    #[error(
+        "Fee share is 0 or exceeds maximum allowed value of {} bps",
+        MAX_FEE_SHARE_BPS
+    )]
+    FeeShareOutOfBounds {},
 }
 
 impl From<OverflowError> for ContractError {

contracts/pair/src/migration.rs

@@ -38,6 +38,7 @@ pub(crate) fn add_asset_balances_tracking_flag(
         price0_cumulative_last: old_config.price0_cumulative_last,
         price1_cumulative_last: old_config.price1_cumulative_last,
         track_asset_balances: false,
+        fee_share: None,
     };
 
     CONFIG.save(storage, &new_config)?;

contracts/pair/src/state.rs

@@ -1,4 +1,7 @@
-use astroport::asset::{AssetInfo, PairInfo};
+use astroport::{
+    asset::{AssetInfo, PairInfo},
+    pair::FeeShareConfig,
+};
 use cosmwasm_schema::cw_serde;
 use cosmwasm_std::{Addr, Uint128};
 use cw_storage_plus::{Item, SnapshotMap};
@@ -18,6 +21,8 @@ pub struct Config {
     pub price1_cumulative_last: Uint128,
     /// Whether asset balances are tracked over blocks or not.
     pub track_asset_balances: bool,
+    // The config for swap fee sharing
+    pub fee_share: Option<FeeShareConfig>,
 }
 
 /// Stores the config struct at the given key

contracts/pair/src/testing.rs

@@ -931,6 +931,7 @@ fn try_native_to_token() {
             attr("spread_amount", expected_spread_amount.to_string()),
             attr("commission_amount", expected_commission_amount.to_string()),
             attr("maker_fee_amount", expected_maker_fee_amount.to_string()),
+            attr("fee_share_amount", "0"),
         ]
     );
 
@@ -1121,6 +1122,7 @@ fn try_token_to_native() {
             attr("spread_amount", expected_spread_amount.to_string()),
             attr("commission_amount", expected_commission_amount.to_string()),
             attr("maker_fee_amount", expected_maker_fee_amount.to_string()),
+            attr("fee_share_amount", "0"),
         ]
     );
 
@@ -1418,6 +1420,7 @@ fn test_accumulate_prices() {
                 price0_cumulative_last: Uint128::new(case.last0),
                 price1_cumulative_last: Uint128::new(case.last1),
                 track_asset_balances: false,
+                fee_share: None,
             },
             Uint128::new(case.x_amount),
             Uint128::new(case.y_amount),