Zero amounts in Lend and staked_astro_lps (#421)

* MP-2522. Filter out zero amount for staked astro lps.

* MP-2521. No error for zero lend.

contracts/credit-manager/src/lend.rs

@@ -2,7 +2,7 @@ use cosmwasm_std::{Coin, Deps, DepsMut, Response, Uint128};
 use mars_types::credit_manager::ActionCoin;
 
 use crate::{
-    error::{ContractError, ContractResult},
+    error::ContractResult,
     state::{COIN_BALANCES, RED_BANK},
     utils::{assert_coin_is_whitelisted, decrement_coin_balance},
 };
@@ -15,29 +15,29 @@ pub fn lend(mut deps: DepsMut, account_id: &str, coin: &ActionCoin) -> ContractR
         amount: get_lend_amount(deps.as_ref(), account_id, coin)?,
     };
 
-    decrement_coin_balance(deps.storage, account_id, &amount_to_lend)?;
+    // Don't error if there is zero amount to lend - just return an empty response
+    let mut res = Response::new();
+    if !amount_to_lend.amount.is_zero() {
+        decrement_coin_balance(deps.storage, account_id, &amount_to_lend)?;
 
-    let red_bank_lend_msg = RED_BANK.load(deps.storage)?.lend_msg(&amount_to_lend, account_id)?;
+        let red_bank_lend_msg =
+            RED_BANK.load(deps.storage)?.lend_msg(&amount_to_lend, account_id)?;
 
-    Ok(Response::new()
-        .add_message(red_bank_lend_msg)
+        res = res.add_message(red_bank_lend_msg);
+    }
+
+    Ok(res
         .add_attribute("action", "lend")
         .add_attribute("account_id", account_id)
         .add_attribute("coin_lent", &amount_to_lend.denom))
 }
 
-/// Queries balance to ensure passing EXACT is not too high.
-/// Also asserts the amount is greater than zero.
+/// Queries balance to ensure passing EXACT is not too high
 fn get_lend_amount(deps: Deps, account_id: &str, coin: &ActionCoin) -> ContractResult<Uint128> {
     let amount_to_lend = if let Some(amount) = coin.amount.value() {
         amount
     } else {
         COIN_BALANCES.may_load(deps.storage, (account_id, &coin.denom))?.unwrap_or(Uint128::zero())
     };
-
-    if amount_to_lend.is_zero() {
-        Err(ContractError::NoAmount)
-    } else {
-        Ok(amount_to_lend)
-    }
+    Ok(amount_to_lend)
 }

contracts/credit-manager/tests/tests/test_lend.rs

@@ -2,9 +2,12 @@ use std::ops::Add;
 
 use cosmwasm_std::{coin, coins, Addr, Coin, OverflowError, OverflowOperation, Uint128};
 use mars_credit_manager::error::ContractError;
-use mars_types::credit_manager::{
-    Action::{Deposit, Lend},
-    ActionAmount, ActionCoin,
+use mars_types::{
+    credit_manager::{
+        Action::{Deposit, Lend},
+        ActionAmount, ActionCoin, Positions,
+    },
+    health::AccountKind,
 };
 
 use super::helpers::{
@@ -54,20 +57,28 @@ fn can_only_lend_what_is_whitelisted() {
 }
 
 #[test]
-fn lending_zero_raises() {
+fn lending_zero_has_no_effect() {
     let coin_info = uosmo_info();
     let user = Addr::unchecked("user");
     let mut mock = MockEnv::new().set_params(&[coin_info.clone()]).build().unwrap();
     let account_id = mock.create_credit_account(&user).unwrap();
 
-    let res = mock.update_credit_account(
-        &account_id,
-        &user,
-        vec![Lend(coin_info.to_action_coin(0))],
-        &[],
-    );
+    mock.update_credit_account(&account_id, &user, vec![Lend(coin_info.to_action_coin(0))], &[])
+        .unwrap();
 
-    assert_err(res, ContractError::NoAmount)
+    let position = mock.query_positions(&account_id);
+    assert_eq!(
+        position,
+        Positions {
+            account_id,
+            account_kind: AccountKind::Default,
+            deposits: vec![],
+            debts: vec![],
+            lends: vec![],
+            vaults: vec![],
+            staked_astro_lps: vec![]
+        }
+    );
 }
 
 #[test]
@@ -104,7 +115,7 @@ fn raises_when_not_enough_assets_to_lend() {
 }
 
 #[test]
-fn raises_when_attempting_to_lend_account_balance_with_no_funds() {
+fn attempting_to_lend_account_balance_with_no_funds() {
     let coin_info = uosmo_info();
 
     let user_a = Addr::unchecked("user_a");
@@ -127,17 +138,30 @@ fn raises_when_attempting_to_lend_account_balance_with_no_funds() {
     let red_bank_collateral = mock.query_red_bank_collateral(&account_id_a, &coin_info.denom);
     assert_eq!(red_bank_collateral.amount, Uint128::zero());
 
-    let res = mock.update_credit_account(
+    mock.update_credit_account(
         &account_id_a,
         &user_a,
         vec![Lend(ActionCoin {
             denom: "uosmo".to_string(),
             amount: ActionAmount::AccountBalance,
         })],
         &[],
-    );
+    )
+    .unwrap();
 
-    assert_err(res, ContractError::NoAmount)
+    let position = mock.query_positions(&account_id_a);
+    assert_eq!(
+        position,
+        Positions {
+            account_id: account_id_a,
+            account_kind: AccountKind::Default,
+            deposits: vec![],
+            debts: vec![],
+            lends: vec![],
+            vaults: vec![],
+            staked_astro_lps: vec![]
+        }
+    );
 }
 
 #[test]

packages/types/src/adapters/incentives.rs

@@ -173,7 +173,9 @@ impl Incentives {
             let response =
                 self.query_staked_astro_lp_positions(querier, account_id, start_after, None)?;
             for item in response.data {
-                all_coins.push(item.lp_coin);
+                if !item.lp_coin.amount.is_zero() {
+                    all_coins.push(item.lp_coin);
+                }
             }
             start_after = all_coins.last().map(|item| item.denom.clone());
             has_more = response.metadata.has_more;