adds a test that tests the number of decimals we can use in stable pool

contracts/pool_stable/src/tests/swap.rs

@@ -5,6 +5,7 @@ use soroban_sdk::{symbol_short, testutils::Address as _, Address, Env, IntoVal};
 
 use super::setup::{deploy_stable_liquidity_pool_contract, deploy_token_contract};
 use crate::storage::{Asset, PoolResponse, SimulateReverseSwapResponse, SimulateSwapResponse};
+use crate::token_contract;
 use soroban_decimal::Decimal;
 
 #[test]
@@ -480,3 +481,95 @@ fn simple_swap_should_panic_after_deadline() {
         &Some(99u64),
     );
 }
+
+#[test]
+fn simple_swap_with_two_tokens_both_with_18_decimals() {
+    let env = Env::default();
+    env.mock_all_auths();
+    env.budget().reset_unlimited();
+
+    let admin = Address::generate(&env);
+    let manager = Address::generate(&env);
+    let factory = Address::generate(&env);
+    let user = Address::generate(&env);
+
+    let mut token1 = token_contract::Client::new(
+        &env,
+        &env.register_contract_wasm(None, token_contract::WASM),
+    );
+
+    token1.initialize(
+        &admin,
+        &7,
+        &"name1".into_val(&env),
+        &"symbol1".into_val(&env),
+    );
+
+    let mut token2 = token_contract::Client::new(
+        &env,
+        &env.register_contract_wasm(None, token_contract::WASM),
+    );
+
+    token2.initialize(
+        &admin,
+        &7,
+        &"name2".into_val(&env),
+        &"symbol2".into_val(&env),
+    );
+
+    if token2.address < token1.address {
+        std::mem::swap(&mut token1, &mut token2);
+    }
+
+    let swap_fees = 0i64;
+    let pool = deploy_stable_liquidity_pool_contract(
+        &env,
+        None,
+        (&token1.address, &token2.address),
+        swap_fees,
+        None,
+        None,
+        None,
+        manager,
+        factory,
+        None,
+    );
+
+    token1.mint(&user, &1_100);
+    token2.mint(&user, &1_100);
+    pool.provide_liquidity(&user, &1_000, &1_000, &None, &None::<u64>);
+
+    let spread = 100i64; // 1% maximum spread allowed
+    pool.swap(
+        &user,
+        &token1.address,
+        &1,
+        &None,
+        &Some(spread),
+        &None::<u64>,
+    );
+
+    let share_token_address = pool.query_share_token_address();
+    let result = pool.query_pool_info();
+
+    assert_eq!(
+        result,
+        PoolResponse {
+            asset_a: Asset {
+                address: token1.address.clone(),
+                amount: 1_001i128,
+            },
+            asset_b: Asset {
+                address: token2.address.clone(),
+                amount: 999i128,
+            },
+            asset_lp_share: Asset {
+                address: share_token_address.clone(),
+                amount: 1_000i128,
+            },
+            stake_address: pool.query_stake_contract_address(),
+        }
+    );
+    assert_eq!(token1.balance(&user), 99);
+    assert_eq!(token2.balance(&user), 101);
+}