Ensure that sender and receiver are not the same in ft_transfer

contracts/near-x/src/errors.rs

@@ -35,6 +35,8 @@ pub const ERROR_EXPECT_RESULT_ON_CALLBACK: &str = "Callback expected result on c
 pub const ERROR_MIN_DEPOSIT_TOO_HIGH: &str = "Min deposit too high";
 pub const ERROR_TEMP_REWARD_FEE_SET_IN_WAIT_PERIOD: &str =
     "Still in wait period for reward fee to be set";
+pub const ERROR_SENDER_RECEIVER_SAME: &str = "Sender and receiver cannot be the same";
+pub const ERROR_REQUIRE_AMOUNT_GT_0: &str = "Amount should be greater than 0";
 
 /// Validator related errors
 pub const ERROR_VALIDATOR_NOT_PAUSED: &str = "Validator not paused";

contracts/near-x/src/fungible_token/nearx_internal.rs

@@ -1,6 +1,7 @@
 use crate::contract::NearxPool;
+use crate::errors::{ERROR_REQUIRE_AMOUNT_GT_0, ERROR_SENDER_RECEIVER_SAME};
 use near_sdk::json_types::U128;
-use near_sdk::{env, log, AccountId, Balance, PromiseResult};
+use near_sdk::{env, log, require, AccountId, Balance, PromiseResult};
 
 impl NearxPool {
     pub fn internal_nearx_transfer(
@@ -9,7 +10,8 @@ impl NearxPool {
         receiver_id: &AccountId,
         amount: u128,
     ) {
-        assert!(amount > 0, "The amount should be a positive number");
+        require!(sender_id != receiver_id, ERROR_SENDER_RECEIVER_SAME);
+        require!(amount > 0, ERROR_REQUIRE_AMOUNT_GT_0);
         let mut sender_acc = self.internal_get_account(sender_id);
         let mut receiver_acc = self.internal_get_account(receiver_id);
         assert!(
@@ -20,9 +22,9 @@ impl NearxPool {
         );
 
         sender_acc.stake_shares -= amount;
-        receiver_acc.stake_shares += amount;
-
         self.internal_update_account(sender_id, &sender_acc);
+
+        receiver_acc.stake_shares += amount;
         self.internal_update_account(receiver_id, &receiver_acc);
     }
 

contracts/near-x/tests/unit_tests.rs

@@ -2,6 +2,7 @@ mod helpers;
 
 use crate::helpers::abs_diff_eq;
 use helpers::ntoy;
+use near_contract_standards::fungible_token::core::FungibleTokenCore;
 use near_sdk::json_types::{U128, U64};
 use near_sdk::test_utils::testing_env_with_promise_results;
 use near_sdk::{
@@ -2891,3 +2892,79 @@ fn test_pause_validator() {
 
     assert_eq!(contract.total_validator_weight, 50);
 }
+
+#[test]
+#[should_panic]
+fn test_ft_transfer_same_user() {
+    let (mut context, mut contract) =
+        contract_setup(owner_account(), operator_account(), treasury_account());
+
+    let user1_account_id = AccountId::from_str("user1").unwrap();
+
+    let user1_account = Account {
+        stake_shares: ntoy(10),
+        unstaked_amount: 0,
+        withdrawable_epoch_height: 0,
+    };
+
+    update_account(&mut contract, user1_account_id.clone(), &user1_account);
+
+    context.predecessor_account_id = user1_account_id.clone();
+    context.attached_deposit = 1;
+    testing_env!(context.clone());
+
+    contract.ft_transfer(user1_account_id.clone(), U128(ntoy(5)), None);
+
+    let user1_account = get_account(&contract, user1_account_id.clone());
+    assert_eq!(
+        user1_account,
+        Account {
+            stake_shares: ntoy(10),
+            unstaked_amount: 0,
+            withdrawable_epoch_height: 0
+        }
+    );
+}
+
+#[test]
+fn test_ft_transfer() {
+    let (mut context, mut contract) =
+        contract_setup(owner_account(), operator_account(), treasury_account());
+
+    let user1_account_id = AccountId::from_str("user1").unwrap();
+    let user2_account_id = AccountId::from_str("user2").unwrap();
+
+    let user1_account = Account {
+        stake_shares: ntoy(10),
+        unstaked_amount: 0,
+        withdrawable_epoch_height: 0,
+    };
+
+    update_account(&mut contract, user1_account_id.clone(), &user1_account);
+
+    context.predecessor_account_id = user1_account_id.clone();
+    context.attached_deposit = 1;
+    testing_env!(context.clone());
+
+    contract.ft_transfer(user2_account_id.clone(), U128(ntoy(5)), None);
+
+    let user1_account = get_account(&contract, user1_account_id.clone());
+    assert_eq!(
+        user1_account,
+        Account {
+            stake_shares: ntoy(5),
+            unstaked_amount: 0,
+            withdrawable_epoch_height: 0
+        }
+    );
+
+    let user2_account = get_account(&contract, user2_account_id.clone());
+    assert_eq!(
+        user2_account,
+        Account {
+            stake_shares: ntoy(5),
+            unstaked_amount: 0,
+            withdrawable_epoch_height: 0
+        }
+    );
+}