Fix Oak no. 3 - stake lp when no existing position (#412)

* fix: handle staking when no lp has yet been staked

* improve comments

* improve test

contracts/incentives/src/astro_incentives.rs

@@ -132,20 +132,29 @@ fn update_user_lp_position(
     credit_manager_addr: &str,
     modification: LpModification,
 ) -> Result<Response, ContractError> {
-    let staked_lp_amount = ASTRO_USER_LP_DEPOSITS
-        .may_load(deps.storage, (&account_id, &lp_coin.denom))?
-        .unwrap_or(Uint128::zero());
+    // Astroport raises an error if there is no existing position and we query rewards.
+    // Therefore, we check first to ensure we don't fail first time somebody stakes
+    // https://github.com/astroport-fi/astroport-core/blob/main/contracts/tokenomics/incentives/src/state.rs#L539
+    let total_staked_lp_amount =
+        ASTRO_TOTAL_LP_DEPOSITS.may_load(deps.storage, &lp_coin.denom)?.unwrap_or(Uint128::zero());
 
     // Claim all rewards from astroport before any modification
-    let mut res = claim_rewards_for_staked_lp_position(
-        &mut deps,
-        astroport_incentives_addr,
-        mars_incentives_addr,
-        credit_manager_addr,
-        account_id,
-        &lp_coin.denom,
-        staked_lp_amount,
-    )?;
+    let mut res = if !total_staked_lp_amount.is_zero() {
+        let staked_lp_amount = ASTRO_USER_LP_DEPOSITS
+            .may_load(deps.storage, (&account_id, &lp_coin.denom))?
+            .unwrap_or(Uint128::zero());
+        claim_rewards_for_staked_lp_position(
+            &mut deps,
+            astroport_incentives_addr,
+            mars_incentives_addr,
+            credit_manager_addr,
+            account_id,
+            &lp_coin.denom,
+            staked_lp_amount,
+        )?
+    } else {
+        Response::new()
+    };
 
     res = match modification {
         // Deposit stakes lp coin in astroport incentives

contracts/mock-astroport-incentives/src/query.rs

@@ -34,6 +34,8 @@ pub fn query_rewards(
             )
             .collect()),
 
-        None => Ok(vec![]),
+        None => Err(cosmwasm_std::StdError::NotFound {
+            kind: "position not found".to_string(),
+        }),
     }
 }

integration-tests/tests/test_astro_lp_incentives.rs

@@ -8,6 +8,35 @@ use mars_testing::integration::mock_env::MockEnvBuilder;
 use crate::helpers::default_asset_params;
 mod helpers;
 
+#[test]
+fn can_be_first_staker() {
+    let owner = Addr::unchecked("owner");
+    let mut mock_env = MockEnvBuilder::new(None, owner).build();
+
+    // Contracts
+    let params = mock_env.params.clone();
+    let incentives = mock_env.incentives.clone();
+    let credit_manager = mock_env.credit_manager.clone();
+
+    // Params
+    let lp_denom = "factory12345";
+    let lp_coin = coin(1_000_000_000, lp_denom.to_string());
+
+    // Set asset params for lp token
+    let (_, asset_params) = default_asset_params(lp_denom);
+    params.init_params(&mut mock_env, asset_params);
+
+    // Fund accounts
+    let funded_amt = 10_000_000_000u128;
+    mock_env.fund_account(&credit_manager, &[coin(funded_amt, lp_denom)]);
+
+    incentives.stake_astro_lp(&mut mock_env, &credit_manager, "1".to_string(), lp_coin.clone());
+
+    let astro_lp_balance =
+        mock_env.query_balance(&mock_env.astro_incentives.contract_addr, lp_denom).unwrap();
+    assert_eq!(astro_lp_balance, lp_coin)
+}
+
 // User A stakes lp in astro and claims rewards
 #[test]
 fn claim_rewards() {