feat(test): add pool_insufficient_balance_for_swap test

src/contract.rs

@@ -189,9 +189,11 @@ pub mod execute {
 
         // Precheck if enough balance in pool for user swap request
         let available_offer = offer.query_pool(&deps.querier, pool_address.clone())?;
-        // TODO: Use a better error type
         if available_offer < amount.into() {
-            return Err(ContractError::Unauthorized {});
+            return Err(ContractError::InsufficientFunds {
+                asked_amount: amount.into(),
+                available_amount: available_offer,
+            });
         }
 
         let asked_asset = if offer.equal(&asset_infos[0]) {

src/error.rs

@@ -1,7 +1,8 @@
 use cosmwasm_std::StdError;
+use cosmwasm_std::Uint128;
 use cw_utils::PaymentError;
 use thiserror::Error;
-#[derive(Error, Debug)]
+#[derive(Error, Debug, PartialEq)]
 pub enum ContractError {
     #[error("{0}")]
     Std(#[from] StdError),
@@ -20,4 +21,9 @@ pub enum ContractError {
     PoolNotExist {},
     #[error("Offer and ask token should not be identical")]
     DoublingAssets {},
+    #[error("Insufficient funds available in the pool to complete the swap: {asked_amount} > {available_amount}")]
+    InsufficientFunds {
+        asked_amount: Uint128,
+        available_amount: Uint128,
+    },
 }

src/integration_tests.rs

@@ -446,4 +446,76 @@ mod tests {
             Uint128::from(500u128)
         );
     }
+    #[test]
+    fn test_pool_insufficient_balance_for_swap() {
+        let owner = Addr::unchecked(ADMIN);
+        let user = Addr::unchecked(USER);
+        let (mut app, cw_contract) = proper_instantiate();
+        let (token_contract, factory_contract, pair_contract) = instantiate_contracts(&mut app);
+        let my_contract = instantiate_my_contract(&mut app);
+        let inj_amount = Uint128::new(1_000_000);
+        let ttt_amount = Uint128::new(1_000_000);
+        let inj_offer = Uint128::new(10_000_000);
+
+        let (msg, coins) =
+            provide_liquidity_msg(ttt_amount, inj_amount, None, None, &token_contract);
+
+        app.execute_contract(owner.clone(), pair_contract.addr(), &msg, &coins)
+            .unwrap();
+        // Enable pool balance tracking
+        let msg = PairExecuteMsg::UpdateConfig {
+            params: to_json_binary(&XYKPoolUpdateParams::EnableAssetBalancesTracking).unwrap(),
+        };
+        app.execute_contract(owner.clone(), pair_contract.addr(), &msg, &[])
+            .unwrap();
+
+        app.update_block(|b| b.height += 1);
+
+        // Check pool balances
+        let res: Option<Uint128> = app
+            .wrap()
+            .query_wasm_smart(
+                pair_contract.addr(),
+                &PairQueryMsg::AssetBalanceAt {
+                    asset_info: AssetInfo::NativeToken {
+                        denom: "ttt".to_string(),
+                    },
+                    block_height: app.block_info().height.into(),
+                },
+            )
+            .unwrap();
+        assert_eq!(res.unwrap(), Uint128::new(1_000_000));
+        // Check pool balances
+        let res: Option<Uint128> = app
+            .wrap()
+            .query_wasm_smart(
+                pair_contract.addr(),
+                &PairQueryMsg::AssetBalanceAt {
+                    asset_info: AssetInfo::NativeToken {
+                        denom: "inj".to_owned(),
+                    },
+                    block_height: app.block_info().height.into(),
+                },
+            )
+            .unwrap();
+        assert_eq!(res.unwrap(), Uint128::new(1_000_000));
+        // Perform swap of two native tokens
+        let swap_msg = crate::msg::ExecuteMsg::MySwap {
+            pool_address: pair_contract.addr(),
+        };
+        let send_funds = vec![Coin {
+            denom: "inj".to_string(),
+            amount: inj_offer,
+        }];
+        let res = app
+            .execute_contract(owner.clone(), my_contract.addr(), &swap_msg, &send_funds)
+            .unwrap_err();
+        assert_eq!(
+            crate::error::ContractError::InsufficientFunds {
+                asked_amount: inj_offer,
+                available_amount: Uint128::new(1_000_000)
+            },
+            res.downcast().unwrap(),
+        );
+    }
 }