add slashing to PoS state machine test

core/src/ledger/storage_api/collections/lazy_vec.rs

@@ -471,6 +471,23 @@ where
         storage.read(&self.get_data_key(index))
     }
 
+    /// Read the first element
+    pub fn front<S>(&self, storage: &S) -> Result<Option<T>>
+    where
+        S: StorageRead,
+    {
+        self.get(storage, 0)
+    }
+
+    /// Read the last element
+    pub fn back<S>(&self, storage: &S) -> Result<Option<T>>
+    where
+        S: StorageRead,
+    {
+        let len = self.len(storage)?;
+        self.get(storage, len - 1)
+    }
+
     /// An iterator visiting all elements. The iterator element type is
     /// `Result<T>`, because iterator's call to `next` may fail with e.g. out of
     /// gas or data decoding error.

proof_of_stake/src/tests.rs

@@ -39,14 +39,14 @@ use crate::{
     bond_tokens, bonds_and_unbonds, consensus_validator_set_handle,
     copy_validator_sets_and_positions, find_validator_by_raw_hash,
     get_num_consensus_validators, init_genesis,
-    insert_validator_into_validator_set,
+    insert_validator_into_validator_set, process_slashes,
     read_below_capacity_validator_set_addresses_with_stake,
     read_consensus_validator_set_addresses_with_stake, read_total_stake,
-    read_validator_delta_value, read_validator_stake, staking_token_address,
-    total_deltas_handle, unbond_handle, unbond_tokens, update_validator_deltas,
-    update_validator_set, validator_consensus_key_handle,
-    validator_set_update_tendermint, validator_state_handle, withdraw_tokens,
-    write_validator_address_raw_hash,
+    read_validator_delta_value, read_validator_stake, slash,
+    staking_token_address, total_deltas_handle, unbond_handle, unbond_tokens,
+    update_validator_deltas, update_validator_set,
+    validator_consensus_key_handle, validator_set_update_tendermint,
+    validator_state_handle, withdraw_tokens, write_validator_address_raw_hash,
 };
 
 proptest! {