set up pool 0 account with rewards

substrate/frame/asset-rewards/src/mock.rs

@@ -163,8 +163,17 @@ pub(crate) fn new_test_ext() -> sp_io::TestExternalities {
 	.assimilate_storage(&mut t)
 	.unwrap();
 
+	let pool_zero_account_id = 31086825966906540362769395565;
 	pallet_balances::GenesisConfig::<MockRuntime> {
-		balances: vec![(1, 10000), (2, 20000), (3, 30000), (4, 40000), (10, 40000), (20, 40000)],
+		balances: vec![
+			(1, 10000),
+			(2, 20000),
+			(3, 30000),
+			(4, 40000),
+			(10, 40000),
+			(20, 40000),
+			(pool_zero_account_id, 100_000), // Top up the default pool account id
+		],
 	}
 	.assimilate_storage(&mut t)
 	.unwrap();