Check era when adding chunk

pallets/dapp-staking-v3/src/test/tests_types.rs

@@ -98,6 +98,9 @@ fn account_ledger_add_lock_amount_works() {
     assert_eq!(acc_ledger.lock_era(), first_era);
     assert_eq!(acc_ledger.locked.0.len(), 1);
 
+    // Adding to previous era should fail
+    assert!(acc_ledger.add_lock_amount(addition, first_era - 1).is_err());
+
     // Add up to storage limit
     for i in 2..=LockedDummy::get() {
         assert!(acc_ledger.add_lock_amount(addition, first_era + i).is_ok());

pallets/dapp-staking-v3/src/types.rs

@@ -95,9 +95,8 @@ where
             return Ok(());
         }
 
-        // TODO: there should be a check to ensure that the era is greater or equal than the last one in vector.
-
         let mut chunk = if let Some(&chunk) = self.0.last() {
+            ensure!(chunk.get_era() <= era, ());
             chunk
         } else {
             P::default()