Merge pull request #900 from daniel-savu/test-loan-batch

test(loans): batched loans accrue interest
interlay · Feb 1, 2023 · 2b17157 · 2b17157
2 parents 765699c + 8fe06b2
commit 2b17157
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Showing 4 changed files with 53 additions and 1 deletion.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/crates/loans/Cargo.toml b/crates/loans/Cargo.toml
@@ -26,6 +26,7 @@ frame-support = { git = "https://github.com/paritytech/substrate", branch = "pol
 frame-system = { git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.31", default-features = false }
 frame-benchmarking = { git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.31", default-features = false, optional = true }
 pallet-timestamp = { git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.31", default-features = false }
+pallet-utility = { git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.31", default-features = false, optional = true }
 
 # Parachain dependencies
 currency = { path = "../currency", default-features = false }
@@ -61,6 +62,7 @@ std = [
 	"frame-system/std",
 	"frame-benchmarking/std",
 	"pallet-timestamp/std",
+	"pallet-utility/std",
 
 	"currency/std",
 	"traits/std",
@@ -75,6 +77,7 @@ runtime-benchmarks = [
 	"frame-benchmarking",
 	"frame-support/runtime-benchmarks",
 	"frame-system/runtime-benchmarks",
+	"pallet-utility/runtime-benchmarks",
 ]
 try-runtime = ["frame-support/try-runtime"]
 integration-tests = [

diff --git a/crates/loans/src/mock.rs b/crates/loans/src/mock.rs
@@ -48,6 +48,7 @@ construct_runtime!(
         TimestampPallet: pallet_timestamp::{Pallet, Call, Storage, Inherent},
         Tokens: orml_tokens::{Pallet, Call, Storage, Config<T>, Event<T>},
         Currency: currency::{Pallet},
+        Utility: pallet_utility,
     }
 );
 
@@ -177,6 +178,13 @@ impl currency::Config for Test {
     type CurrencyConversion = Conversion;
 }
 
+impl pallet_utility::Config for Test {
+    type RuntimeEvent = RuntimeEvent;
+    type RuntimeCall = RuntimeCall;
+    type PalletsOrigin = OriginCaller;
+    type WeightInfo = ();
+}
+
 parameter_types! {
     pub const MaxLocks: u32 = 50;
 }

diff --git a/crates/loans/src/tests/edge_cases.rs b/crates/loans/src/tests/edge_cases.rs
@@ -1,7 +1,7 @@
 use super::*;
 use crate::{mock::*, tests::Loans, Error};
 use currency::Amount;
-use frame_support::{assert_err, assert_ok};
+use frame_support::{assert_err, assert_ok, dispatch::Dispatchable};
 use primitives::{
     CurrencyId::{ForeignAsset, Token},
     DOT, IBTC, KSM,
@@ -269,6 +269,46 @@ fn new_transferred_collateral_is_not_auto_deposited_if_not_collateral() {
 
 #[test]
 fn small_loans_have_interest_rounded_up() {
+    new_test_ext().execute_with(|| {
+        assert_ok!(Loans::mint(RuntimeOrigin::signed(ALICE), Token(IBTC), unit(100)));
+        assert_ok!(Loans::mint(RuntimeOrigin::signed(BOB), Token(DOT), unit(100)));
+        assert_ok!(Loans::deposit_all_collateral(RuntimeOrigin::signed(BOB), Token(DOT)));
+
+        let initial_block = 2;
+        _run_to_block(initial_block);
+
+        assert_eq!(Tokens::balance(Token(IBTC), &BOB), 0);
+        let borrow_amount_small = 1;
+        let borrow_amount_big = unit(10);
+        // If there was an bug in the lazy interest accrual, the second loan would be interest-free
+        let batch_call = RuntimeCall::Utility(pallet_utility::Call::batch {
+            calls: vec![
+                RuntimeCall::Loans(self::Call::borrow {
+                    asset_id: Token(IBTC),
+                    borrow_amount: borrow_amount_small,
+                }),
+                RuntimeCall::Loans(self::Call::borrow {
+                    asset_id: Token(IBTC),
+                    borrow_amount: borrow_amount_big,
+                }),
+            ],
+        });
+        assert_ok!(batch_call.clone().dispatch(RuntimeOrigin::signed(BOB)));
+
+        _run_to_block(initial_block + 10000);
+        Loans::accrue_interest(Token(IBTC)).unwrap();
+        let borrow_index = Loans::borrow_index(Token(IBTC));
+        let current_borrow_balance = Loans::current_borrow_balance(&BOB, Token(IBTC)).unwrap();
+        let total_borrowed_amount = borrow_amount_small + borrow_amount_big;
+        let expected_borrow_balance = borrow_index.checked_mul_int(total_borrowed_amount).unwrap();
+        assert_eq!(
+            almost_equal(current_borrow_balance.amount(), expected_borrow_balance),
+            true,
+        );
+    })
+}
+
+fn big_loan_following_a_small_loan_still_accrues_interest() {
     new_test_ext().execute_with(|| {
         assert_ok!(Loans::mint(RuntimeOrigin::signed(ALICE), Token(IBTC), unit(100)));
         assert_ok!(Loans::mint(RuntimeOrigin::signed(BOB), Token(DOT), unit(100)));