diff --git a/contracts/battleship/src/lib.rs b/contracts/battleship/src/lib.rs
index 7c871fc77..1611e3004 100644
--- a/contracts/battleship/src/lib.rs
+++ b/contracts/battleship/src/lib.rs
@@ -1,7 +1,5 @@
 #![no_std]
 
-#[cfg(not(feature = "binary-vendor"))]
 mod contract;
 
-#[cfg(feature = "binary-vendor")]
 include!(concat!(env!("OUT_DIR"), "/wasm_binary.rs"));
diff --git a/contracts/battleship/tests/load_testing.rs b/contracts/battleship/tests/load_testing.rs
index ef2327be1..faefd32f9 100644
--- a/contracts/battleship/tests/load_testing.rs
+++ b/contracts/battleship/tests/load_testing.rs
@@ -83,7 +83,7 @@ async fn transfer_balances_to_account(accounts: &[String], nonce: u32) -> Result
     // let mut api = GearApi::dev().await?;
     let mut api = GearApi::init(WSAddress::new("wss://testnet.vara.rs", 443)).await?;
     let accounts = accounts.to_vec();
-    for (_, account) in accounts.iter().enumerate() {
+    for account in accounts.iter() {
         let account = api.get_specific_actor_id(account);
 
         let account: [u8; 32] = account.into();
diff --git a/contracts/dao-light/src/lib.rs b/contracts/dao-light/src/lib.rs
index b4c4db873..127a87c6a 100644
--- a/contracts/dao-light/src/lib.rs
+++ b/contracts/dao-light/src/lib.rs
@@ -89,7 +89,7 @@ impl Dao {
     /// * The proposal can be submitted only by the existing members or their delegate addresses
     /// * The applicant ID can't be the zero
     /// * The DAO must have enough funds to finance the proposal
-    /// Arguments:
+    ///   Arguments:
     /// * `applicant`: an actor that will be funded
     /// * `amount`: the number of fungible tokens that will be sent to the applicant
     /// * `quorum`: a certain threshold of YES votes in order for the proposal to pass
@@ -155,7 +155,7 @@ impl Dao {
     /// * The proposal can be submitted only by the existing members or their delegate addresses
     /// * The member can vote on the proposal only once
     /// * Proposal must exist, the voting period must has started and not expired
-    /// Arguments:
+    ///   Arguments:
     /// * `proposal_id`: the proposal ID
     /// * `vote`: the member  a member vote (YES or NO)
     fn submit_vote(&mut self, proposal_id: u128, vote: Vote) {
@@ -216,7 +216,7 @@ impl Dao {
     /// * The previous proposal must be processed
     /// * The proposal must exist and be ready for processing
     /// * The proposal must not be already be processed
-    /// Arguments:
+    ///   Arguments:
     /// * `proposal_id`: the proposal ID
     async fn process_proposal(&mut self, proposal_id: u128) {
         if proposal_id > 0 && !self.proposals.get(&(&proposal_id - 1)).unwrap().processed {
@@ -277,7 +277,7 @@ impl Dao {
     /// * `msg::source()` must be DAO member
     /// * The member must have sufficient amount of shares
     /// * The latest proposal the member voted YES must be processed
-    /// Arguments:
+    ///   Arguments:
     /// * `amount`: The amount of shares the member would like to withdraw
     async fn ragequit(&mut self, amount: u128) {
         if !self.members.contains_key(&msg::source()) {
diff --git a/contracts/dex/factory/io/src/lib.rs b/contracts/dex/factory/io/src/lib.rs
index 6c51530b7..56aedc766 100644
--- a/contracts/dex/factory/io/src/lib.rs
+++ b/contracts/dex/factory/io/src/lib.rs
@@ -81,7 +81,7 @@ pub enum Action {
     ///
     /// # Requirements:
     /// - [`msg::source`](gstd::msg::source) must have the right to set the fee
-    /// receiver (must be equal to `fee_to_setter`).
+    ///   receiver (must be equal to `fee_to_setter`).
     ///
     /// On success, replies with [`Event::FeeToSet`].
     FeeTo(ActorId),
@@ -91,7 +91,7 @@ pub enum Action {
     ///
     /// # Requirements:
     /// - [`msg::source`](gstd::msg::source) must be equal to current
-    /// `fee_to_setter`.
+    ///   `fee_to_setter`.
     ///
     /// On success, replies with [`Event::FeeToSetterSet`].
     FeeToSetter(ActorId),
diff --git a/contracts/dex/io/src/lib.rs b/contracts/dex/io/src/lib.rs
index 9e5494108..f35b3083a 100644
--- a/contracts/dex/io/src/lib.rs
+++ b/contracts/dex/io/src/lib.rs
@@ -77,7 +77,7 @@ pub enum InnerAction {
     /// # Requirements
     /// - `amount_a_desired` & `amount_b_desired` mustn't equal to 0.
     /// - On the first addition (first mint), a resulted amount of pool tokens
-    /// must be more than [`MINIMUM_LIQUIDITY`].
+    ///   must be more than [`MINIMUM_LIQUIDITY`].
     ///
     /// On success, replies with [`Event::AddedLiquidity`].
     AddLiquidity {
@@ -105,7 +105,7 @@ pub enum InnerAction {
     ///
     /// # Requirements
     /// - [`msg::source()`] must have the same or a greater amount of liquidity
-    /// tokens than a given one.
+    ///   tokens than a given one.
     ///
     /// On success, replies with [`Event::RemovedLiquidity`].
     ///
@@ -184,7 +184,7 @@ pub enum InnerAction {
     ///
     /// # Requirements
     /// - [`msg::source()`] must have the same or a greater amount of liquidity
-    /// tokens than a given one.
+    ///   tokens than a given one.
     ///
     /// On success, replies with [`Event::Transfer`].
     ///
diff --git a/contracts/galactic-express/.binpath b/contracts/galactic-express/.binpath
index 27edebedf..b4c198035 100644
--- a/contracts/galactic-express/.binpath
+++ b/contracts/galactic-express/.binpath
@@ -1 +1 @@
-../target/wasm32-unknown-unknown/debug/galactic_express
\ No newline at end of file
+../target/wasm32-unknown-unknown/release/galactic_express
\ No newline at end of file
diff --git a/contracts/galactic-express/tests/utils/common.rs b/contracts/galactic-express/tests/utils/common.rs
index 5a2b5c68f..7064af081 100644
--- a/contracts/galactic-express/tests/utils/common.rs
+++ b/contracts/galactic-express/tests/utils/common.rs
@@ -1,5 +1,5 @@
-use gstd::{fmt::Debug, marker::PhantomData, prelude::*, ActorId};
-use gtest::{Log, Program as InnerProgram, RunResult as InnerRunResult, System};
+use gstd::{fmt::Debug, marker::PhantomData, prelude::*};
+use gtest::{Log, RunResult as InnerRunResult, System};
 
 pub fn initialize_system() -> System {
     let system = System::new();
diff --git a/contracts/game-of-chance/io/src/lib.rs b/contracts/game-of-chance/io/src/lib.rs
index 844960972..b3c974c32 100644
--- a/contracts/game-of-chance/io/src/lib.rs
+++ b/contracts/game-of-chance/io/src/lib.rs
@@ -95,10 +95,10 @@ pub enum Action {
     /// - The players entry stage mustn't be over.
     /// - [`msg::source()`] mustn't already participate.
     /// - [`msg::source()`] must have enough currency to pay a participation
-    /// cost.
+    ///   cost.
     /// - If the current game round currency is the native value
-    /// (`fungible_token` is [`None`]), [`msg::source()`] must send this action
-    /// with the amount of the value exactly equal to a participation cost.
+    ///   (`fungible_token` is [`None`]), [`msg::source()`] must send this action
+    ///   with the amount of the value exactly equal to a participation cost.
     ///
     /// On success, replies with [`Event::PlayerAdded`].
     ///
diff --git a/contracts/game-of-chance/tests/utils/prelude.rs b/contracts/game-of-chance/tests/utils/prelude.rs
index 73254509f..33ab122fb 100644
--- a/contracts/game-of-chance/tests/utils/prelude.rs
+++ b/contracts/game-of-chance/tests/utils/prelude.rs
@@ -1,4 +1,3 @@
 pub use super::{common::Program, Goc, FOREIGN_USER};
 pub use game_of_chance_io::*;
 pub use gstd::{prelude::*, ActorId};
-pub use sharded_fungible_token_io::FTokenEvent;
diff --git a/contracts/gear-lib-old/src/fungible_token/ft_core.rs b/contracts/gear-lib-old/src/fungible_token/ft_core.rs
index e5cf74ac8..7cb0f09e7 100644
--- a/contracts/gear-lib-old/src/fungible_token/ft_core.rs
+++ b/contracts/gear-lib-old/src/fungible_token/ft_core.rs
@@ -32,8 +32,8 @@ pub trait FTCore: FTStateKeeper {
     ///
     /// Requirements:
     /// * `msg::source()` MUST have enough tokens on his balance
-    /// Arguments:
-    /// `amount`: The amount of token to be burnt
+    ///   Arguments:
+    ///   `amount`: The amount of token to be burnt
     fn burn(&mut self, amount: u128) {
         if self
             .get()
diff --git a/contracts/gear-lib-old/src/multitoken/mtk_core.rs b/contracts/gear-lib-old/src/multitoken/mtk_core.rs
index f59c6fd6a..265a8c603 100644
--- a/contracts/gear-lib-old/src/multitoken/mtk_core.rs
+++ b/contracts/gear-lib-old/src/multitoken/mtk_core.rs
@@ -48,7 +48,7 @@ pub trait MTKCore: StateKeeper + MTKTokenState {
     /// Requirements:
     /// * `ids` element must a unique value
     /// * `account` must be a non-zero account
-    /// Arguments:
+    ///   Arguments:
     /// * `account`: An account to which minted token will be assigned
     /// * `ids`: The vector of IDs of minted tokens
     /// * `amounts`: The vector of amounts of tokens to mint (1 in case of an NFT)
@@ -100,7 +100,7 @@ pub trait MTKCore: StateKeeper + MTKTokenState {
     /// * Only token owner can perform this action
     /// * `ids` element must be the ID of the existing token
     /// * `amounts` element must not exceed user's token balance
-    /// Arguments:
+    ///   Arguments:
     /// * `ids`: The vector of ids of the token to be burnt
     /// * `amounts`: The vector of amounts of token to be burnt
     fn burn(&mut self, ids: Vec<TokenId>, amounts: Vec<u128>) {
@@ -147,7 +147,7 @@ pub trait MTKCore: StateKeeper + MTKTokenState {
     /// * `to` must be a non-zero account
     /// * `ids` element must be the ID of the existing token
     /// * `amounts` element must not exceed from's balance
-    /// Arguments:
+    ///   Arguments:
     /// * `from`: An account from which token will be transferred
     /// * `to`: An account to which token will be transferred
     /// * `ids`: The vector of IDs of transferred token
@@ -200,7 +200,7 @@ pub trait MTKCore: StateKeeper + MTKTokenState {
     /// Requirements:
     /// * Only the token owner can call that action
     /// * `to` must be a non-zero account
-    /// Arguments:
+    ///   Arguments:
     /// * `to`: An account that will be approved to manage the tokens
     fn approve(&mut self, to: &ActorId) {
         if to == &ZERO_ID {
@@ -225,7 +225,7 @@ pub trait MTKCore: StateKeeper + MTKTokenState {
     /// Requirements:
     /// * Only the token owner can call that action
     /// * `to` must be a non-zero account
-    /// Arguments:
+    ///   Arguments:
     /// * `to`: An account that won't be able to manage the tokens
     fn revoke_approval(&mut self, to: &ActorId) {
         self.get_mut()
diff --git a/contracts/gear-lib/src/tokens/fungible.rs b/contracts/gear-lib/src/tokens/fungible.rs
index 6c8ff607f..89f5d6854 100644
--- a/contracts/gear-lib/src/tokens/fungible.rs
+++ b/contracts/gear-lib/src/tokens/fungible.rs
@@ -38,7 +38,7 @@ impl FTState {
     ///
     /// # Errors
     /// - [`FTError::ZeroRecipientAddress`] if `operator` is
-    /// [`ActorId::zero()`].
+    ///   [`ActorId::zero()`].
     pub fn approve(&mut self, operator: Operator, amount: Amount) -> Result<FTApproval, FTError> {
         self.internal_approve(msg::source(), operator, amount)
     }
@@ -96,7 +96,7 @@ impl FTState {
     /// # Errors
     /// - [`FTError::ZeroRecipientAddress`] if `to` is [`ActorId::zero()`].
     /// - [`FTError::InsufficientAmount`] if [`msg::source()`] doesn't have
-    /// given `amount` of tokens.
+    ///   given `amount` of tokens.
     pub fn transfer(&mut self, to: ActorId, amount: Amount) -> Result<FTTransfer, FTError> {
         self.internal_transfer(msg::source(), to, amount)
     }
@@ -146,9 +146,9 @@ impl FTState {
     /// - [`FTError::ZeroSenderAddress`] if `from` is [`ActorId::zero()`].
     /// - [`FTError::ZeroRecipientAddress`] if `to` is [`ActorId::zero()`].
     /// - [`FTError::InsufficientAllowance`] if [`msg::source()`] doesn't have
-    /// an allowance for given `amount` of tokens.
+    ///   an allowance for given `amount` of tokens.
     /// - [`FTError::InsufficientAmount`] if `from` doesn't have given `amount`
-    /// of tokens.
+    ///   of tokens.
     pub fn transfer_from(
         &mut self,
         from: Owner,
@@ -186,7 +186,7 @@ impl FTState {
     ///
     /// # Errors
     /// - [`FTError::InsufficientAllowance`] if given `delta_amount` with the
-    /// current allowance overflows the [`Amount`] type.
+    ///   current allowance overflows the [`Amount`] type.
     pub fn increase_allowance(
         &mut self,
         operator: Operator,
@@ -204,7 +204,7 @@ impl FTState {
     ///
     /// # Errors
     /// - [`FTError::InsufficientAllowance`] if `operator` doesn't have given
-    /// `delta_amount` of an allowance.
+    ///   `delta_amount` of an allowance.
     pub fn decrease_allowance(
         &mut self,
         operator: Operator,
@@ -222,7 +222,7 @@ impl FTState {
     /// # Errors
     /// - [`FTError::ZeroRecipientAddress`] if `to` is [`ActorId::zero()`].
     /// - [`FTError::InsufficientAmount`] if given `amount` with the current
-    /// total token supply overflows the [`Amount`] type.
+    ///   total token supply overflows the [`Amount`] type.
     pub fn mint(&mut self, to: ActorId, amount: Amount) -> Result<FTTransfer, FTError> {
         if to.is_zero() {
             return Err(FTError::ZeroRecipientAddress);
@@ -248,7 +248,7 @@ impl FTState {
     /// # Errors
     /// - [`FTError::ZeroSenderAddress`] if `from` is [`ActorId::zero()`].
     /// - [`FTError::InsufficientAmount`] if `from` doesn't have given `amount`
-    /// of tokens.
+    ///   of tokens.
     pub fn burn(&mut self, from: Owner, amount: Amount) -> Result<FTTransfer, FTError> {
         if from.is_zero() {
             return Err(FTError::ZeroSenderAddress);
diff --git a/contracts/gear-lib/src/tokens/multi.rs b/contracts/gear-lib/src/tokens/multi.rs
index 92dd07f62..c64b717cc 100644
--- a/contracts/gear-lib/src/tokens/multi.rs
+++ b/contracts/gear-lib/src/tokens/multi.rs
@@ -86,7 +86,7 @@ impl MTState {
     /// # Errors
     /// - [`MTError::ZeroRecipientAddress`] if `to` is [`ActorId::zero()`].
     /// - [`MTError::InsufficientAmount`] if given `amount` with the total
-    /// supply of all the tokens overflows the [`Amount`] type.
+    ///   supply of all the tokens overflows the [`Amount`] type.
     pub fn mint(&mut self, to: ActorId, id: Id, amount: Amount) -> Result<MTTransfer, MTError> {
         self.mint_batch(to, vec![(id.clone(), amount)])?;
 
@@ -141,7 +141,7 @@ impl MTState {
     /// # Errors
     /// - [`MTError::ZeroSenderAddress`] if `from` is [`ActorId::zero()`].
     /// - [`MTError::InsufficientAmount`] if `from` doesn't have given `amount`
-    /// of the tokens.
+    ///   of the tokens.
     pub fn burn(&mut self, from: Owner, id: Id, amount: Amount) -> Result<MTTransfer, MTError> {
         self.burn_batch(from, vec![(id.clone(), amount)])?;
 
@@ -228,9 +228,9 @@ impl MTState {
     ///
     /// # Errors
     /// - [`MTError::ZeroRecipientAddress`] if `operator` is
-    /// [`ActorId::zero()`].
+    ///   [`ActorId::zero()`].
     /// - [`MTError::InsufficientAmount`] if [`msg::source()`] doesn't have any
-    /// tokens or there are no tokens with given `id`.
+    ///   tokens or there are no tokens with given `id`.
     pub fn approve(
         &mut self,
         operator: Operator,
@@ -276,9 +276,9 @@ impl MTState {
     /// Returns an allowance of `owner`'s tokens for `operator`.
     ///
     /// - If `id` is [`Some`], returns an approved amount of the tokens with
-    /// this `id`.
+    ///   this `id`.
     /// - If `id` is [`None`], returns [`Amount::MAX`] if `operator` is approved
-    /// for all `owner`s tokens, otherwise returns 0.
+    ///   for all `owner`s tokens, otherwise returns 0.
     pub fn allowance(&self, owner: Owner, operator: Operator, id: Option<&Id>) -> Amount {
         id.map_or_else(
             || {
@@ -307,7 +307,7 @@ impl MTState {
     /// # Errors
     /// - [`MTError::ZeroRecipientAddress`] if `to` is [`ActorId::zero()`].
     /// - [`MTError::InsufficientAmount`] if [`msg::source()`] doesn't have
-    /// given `amount` of the tokens.
+    ///   given `amount` of the tokens.
     pub fn transfer(&mut self, to: ActorId, id: Id, amount: Amount) -> Result<MTTransfer, MTError> {
         self.transfer_batch(to, vec![(id.clone(), amount)])?;
 
@@ -325,7 +325,7 @@ impl MTState {
     /// # Errors
     /// - [`MTError::ZeroRecipientAddress`] if `to` is [`ActorId::zero()`].
     /// - [`MTError::InsufficientAmount`] if [`msg::source()`] doesn't have
-    /// given amount of one of given tokens.
+    ///   given amount of one of given tokens.
     pub fn transfer_batch(
         &mut self,
         to: ActorId,
@@ -401,9 +401,9 @@ impl MTState {
     /// - [`MTError::ZeroSenderAddress`] if `from` is [`ActorId::zero()`].
     /// - [`MTError::ZeroRecipientAddress`] if `to` is [`ActorId::zero()`].
     /// - [`MTError::NotApproved`] if [`msg::source()`] doesn't have any
-    /// allowance for given `amount` of the tokens.
+    ///   allowance for given `amount` of the tokens.
     /// - [`MTError::InsufficientAmount`] if `from` doesn't have given `amount`
-    /// of the tokens.
+    ///   of the tokens.
     pub fn transfer_from(
         &mut self,
         from: Owner,
@@ -437,9 +437,9 @@ impl MTState {
     /// - [`MTError::ZeroSenderAddress`] if `from` is [`ActorId::zero()`].
     /// - [`MTError::ZeroRecipientAddress`] if `to` is [`ActorId::zero()`].
     /// - [`MTError::NotApproved`] if [`msg::source()`] doesn't have any
-    /// allowance for given amounts of tokens.
+    ///   allowance for given amounts of tokens.
     /// - [`MTError::InsufficientAmount`] if `from` doesn't have given amount of
-    /// one of given tokens.
+    ///   one of given tokens.
     pub fn transfer_from_batch(
         &mut self,
         from: Owner,
@@ -548,7 +548,7 @@ impl MTState {
     ///
     /// # Errors
     /// - [`MTError::InsufficientAmount`] if there are no tokens with given
-    /// `id`.
+    ///   `id`.
     pub fn get_attribute(&self, id: &Id, key: &Vec<u8>) -> Result<Option<&Vec<u8>>, MTError> {
         self.tokens
             .get(id)
@@ -569,7 +569,7 @@ impl MTState {
     ///
     /// # Errors
     /// - [`MTError::InsufficientAmount`] if there are no tokens with given
-    /// `id`.
+    ///   `id`.
     pub fn set_attribute(
         &mut self,
         id: &Id,
diff --git a/contracts/gear-lib/src/tokens/non_fungible.rs b/contracts/gear-lib/src/tokens/non_fungible.rs
index 9a706051e..b066f8eba 100644
--- a/contracts/gear-lib/src/tokens/non_fungible.rs
+++ b/contracts/gear-lib/src/tokens/non_fungible.rs
@@ -69,10 +69,10 @@ impl NFTState {
     /// tokens or the token with given `id`.
     ///
     /// - If `id` is [`Some`], firstly checks if `operator` is allowed for all
-    /// `owner`'s tokens, and if not, whether `operator` is allowed for the
-    /// token with this `id`.
+    ///   `owner`'s tokens, and if not, whether `operator` is allowed for the
+    ///   token with this `id`.
     /// - If `id` is [`None`], only checks if `operator` is allowed for all
-    /// `owner`'s tokens.
+    ///   `owner`'s tokens.
     pub fn allowance(&self, owner: Owner, operator: Operator, id: Option<&Id>) -> bool {
         Self::inner_allowance(
             &self.owners,
@@ -109,7 +109,7 @@ impl NFTState {
     /// - [`NFTError::ZeroRecipientAddress`] if `to` is [`ActorId::zero()`].
     /// - [`NFTError::TokenNotExists`] if the token doesn't exist.
     /// - [`NFTError::NotApproved`] if [`msg::source()`] isn't the owner of the
-    /// token and doesn't have any allowance for its transfer.
+    ///   token and doesn't have any allowance for its transfer.
     pub fn transfer(&mut self, to: ActorId, id: Id) -> Result<NFTTransfer, NFTError> {
         if to.is_zero() {
             return Err(NFTError::ZeroRecipientAddress);
@@ -141,19 +141,19 @@ impl NFTState {
     /// tokens or only the one with given `id`.
     ///
     /// - If `id` is [`Some`], sets an approval only for the token with this
-    /// `id`.
+    ///   `id`.
     /// - If `id` is [`None`], sets an approval for all [`msg::source()`]'s
-    /// tokens.
+    ///   tokens.
     ///
     /// If [`msg::source()`] is an operator of all tokens of the owner of the
     /// token with given `id`, [`msg::source()`] can also set approval for them.
     ///
     /// # Errors
     /// - [`NFTError::ZeroRecipientAddress`] if `operator` is
-    /// [`ActorId::zero()`].
+    ///   [`ActorId::zero()`].
     /// - [`NFTError::TokenNotExists`] if the token doesn't exist.
     /// - [`NFTError::NotApproved`] if [`msg::source()`] isn't the owner of the
-    /// token and operator of token's owner's tokens.
+    ///   token and operator of token's owner's tokens.
     pub fn approve(
         &mut self,
         operator: Operator,
@@ -214,7 +214,7 @@ impl NFTState {
     /// # Errors
     /// - [`NFTError::ZeroRecipientAddress`] if `to` is [`ActorId::zero()`].
     /// - [`NFTError::TokenNotExists`] if the total supply of tokens reached the
-    /// maximum limit of the [`Amount`] type.
+    ///   maximum limit of the [`Amount`] type.
     /// - [`NFTError::TokenExists`] if the token with given `id` already exists.
     pub fn mint(&mut self, to: ActorId, id: Id) -> Result<NFTTransfer, NFTError> {
         if to.is_zero() {
diff --git a/contracts/gear-lib/src/tokens/non_fungible/encodable.rs b/contracts/gear-lib/src/tokens/non_fungible/encodable.rs
index e96a47799..fb22e06bf 100644
--- a/contracts/gear-lib/src/tokens/non_fungible/encodable.rs
+++ b/contracts/gear-lib/src/tokens/non_fungible/encodable.rs
@@ -42,10 +42,10 @@ impl NFTState {
     /// tokens or the token with given `id`.
     ///
     /// - If `id` is [`Some`], firstly checks if `operator` is allowed for all
-    /// `owner`'s tokens, and if not, whether `operator` is allowed for the
-    /// token with given `id`.
+    ///   `owner`'s tokens, and if not, whether `operator` is allowed for the
+    ///   token with given `id`.
     /// - If `id` is [`None`], only checks if `operator` is allowed for all
-    /// `owner`'s tokens.
+    ///   `owner`'s tokens.
     pub fn allowance(&self, owner: Owner, operator: Operator, id: Option<&Id>) -> bool {
         self.owners
             .iter()
diff --git a/contracts/gear-lib/src/tx_manager.rs b/contracts/gear-lib/src/tx_manager.rs
index 30efabc06..3e1a3203f 100644
--- a/contracts/gear-lib/src/tx_manager.rs
+++ b/contracts/gear-lib/src/tx_manager.rs
@@ -109,14 +109,14 @@ impl<T> TransactionManager<T> {
     ///
     /// Important notes:
     /// - Only one transaction for each `msg_source` is cached. Hence an attempt
-    /// to save a [new](TransactionKind::New) transaction over a failed one will
-    /// delete the failed one, so it'll be **impossible** to
-    /// [retry](TransactionKind::Retry) the latter.
+    ///   to save a [new](TransactionKind::New) transaction over a failed one will
+    ///   delete the failed one, so it'll be **impossible** to
+    ///   [retry](TransactionKind::Retry) the latter.
     /// - There's no guarantee every underprocessed asynchronous action will
-    /// result in a cached transaction. Usually caching occurs after the first
-    /// blocking `.await` during action processing.
+    ///   result in a cached transaction. Usually caching occurs after the first
+    ///   blocking `.await` during action processing.
     /// - The cache memory has a limit, so when it's reached every oldest cached
-    /// transaction is replaced with a new one. See also [`DEFAULT_TX_LIMIT`].
+    ///   transaction is replaced with a new one. See also [`DEFAULT_TX_LIMIT`].
     ///
     /// # Errors
     /// [`TransactionManagerError::TransactionNotFound`] if `kind` is
diff --git a/contracts/multi-token/io/src/lib.rs b/contracts/multi-token/io/src/lib.rs
index c4a706dc3..14d3be6bd 100644
--- a/contracts/multi-token/io/src/lib.rs
+++ b/contracts/multi-token/io/src/lib.rs
@@ -117,8 +117,8 @@ pub enum MtkAction {
     ///
     /// # Requirements:
     /// * if minting an NFT with a specific TokenId at index `idx`
-    /// `amounts[idx]` MUST be equal to 1,
-    /// *`tokens_metadata` size MUST equal to the length of ids.
+    ///   `amounts[idx]` MUST be equal to 1,
+    ///   *`tokens_metadata` size MUST equal to the length of ids.
     /// * a sender MUST be an owner or an approved account.
     ///
     /// On success returns `MtkEvent::Transfer`
diff --git a/contracts/multi-token/src/lib.rs b/contracts/multi-token/src/lib.rs
index 5b3de41cd..eb046577a 100644
--- a/contracts/multi-token/src/lib.rs
+++ b/contracts/multi-token/src/lib.rs
@@ -243,7 +243,7 @@ impl SimpleMtk {
     /// * `to` must be a non-zero account
     /// * `ids` element must be the ID of the existing token
     /// * `amounts` element must not exceed from's balance
-    /// Arguments:
+    ///   Arguments:
     /// * `from`: An account from which token will be transferred
     /// * `to`: An account to which token will be transferred
     /// * `ids`: The vector of IDs of transferred token
@@ -306,7 +306,7 @@ impl SimpleMtk {
     /// Requirements:
     /// * Only the token owner can call that action
     /// * `to` must be a non-zero account
-    /// Arguments:
+    ///   Arguments:
     /// * `to`: An account that will be approved to manage the tokens
     fn approve(&mut self, to: &ActorId) -> Result<MtkEvent, MtkError> {
         if to == &ActorId::zero() {
@@ -331,7 +331,7 @@ impl SimpleMtk {
     /// Requirements:
     /// * Only the token owner can call that action
     /// * `to` must be a non-zero account
-    /// Arguments:
+    ///   Arguments:
     /// * `to`: An account that won't be able to manage the tokens
     fn revoke_approval(&mut self, to: &ActorId) -> Result<MtkEvent, MtkError> {
         let msg_src = &msg::source();
diff --git a/contracts/nft-pixelboard/io/src/lib.rs b/contracts/nft-pixelboard/io/src/lib.rs
index d5ac63662..d5d38159d 100644
--- a/contracts/nft-pixelboard/io/src/lib.rs
+++ b/contracts/nft-pixelboard/io/src/lib.rs
@@ -157,12 +157,12 @@ pub struct TokenInfo {
 /// * `block_side_length` must be more than 0.
 /// * `pixel_price` mustn't be more than [`MAX_PIXEL_PRICE`].
 /// * A [width](`Resolution#structfield.width`) &
-/// [height](`Resolution#structfield.height`) (`resolution`) of a canvas must be
-/// more than 0.
+///   [height](`Resolution#structfield.height`) (`resolution`) of a canvas must be
+///   more than 0.
 /// * Each side of `resolution` must be a multiple of `block_side_length`.
 /// * `painting` length must equal a pixel count in a canvas (which can be
-/// calculated by multiplying a [width](`Resolution#structfield.width`) &
-/// [height](`Resolution#structfield.height`) from `resolution`).
+///   calculated by multiplying a [width](`Resolution#structfield.width`) &
+///   [height](`Resolution#structfield.height`) from `resolution`).
 /// * `commission_percentage` mustn't be more than 100.
 /// * `ft_program` address mustn't be [`ActorId::zero()`].
 /// * `nft_program` address mustn't be [`ActorId::zero()`].
@@ -208,22 +208,22 @@ pub enum NFTPixelboardAction {
     /// # Requirements
     /// * `rectangle` coordinates mustn't be out of a canvas.
     /// * `rectangle` coordinates mustn't be mixed up or belong to wrong
-    /// corners.
+    ///   corners.
     /// * `rectangle` coordinates must observe a block layout. In other words,
-    /// each `rectangle` coordinate must be a multiple of a block side length in
-    /// the canvas. The block side length can be obtained by
-    /// [`block_side_length()`](../nft_pixelboard_state/metafns/fn.block_side_length.html).
+    ///   each `rectangle` coordinate must be a multiple of a block side length in
+    ///   the canvas. The block side length can be obtained by
+    ///   [`block_side_length()`](../nft_pixelboard_state/metafns/fn.block_side_length.html).
     /// * NFT `rectangle` mustn't collide with already minted one.
     /// * `painting` length must equal a pixel count in an NFT
-    /// (which can be calculated by multiplying a [width](`Rectangle::width`) &
-    /// [height](`Rectangle::height`) from `rectangle`).
+    ///   (which can be calculated by multiplying a [width](`Rectangle::width`) &
+    ///   [height](`Rectangle::height`) from `rectangle`).
     /// * [`msg::source()`] must have enough fungible tokens to buy all free
-    /// pixels that `rectangle` will occupy. An enough number of tokens can be
-    /// calculated by multiplying a `rectangle` area and the price of a free
-    /// pixel. The area can be calculated by multiplying a
-    /// [width](`Rectangle::width`) & [height](`Rectangle::height`) from
-    /// `rectangle`. The price of a free pixel can be obtained by
-    /// [`pixel_price()`](../nft_pixelboard_state/metafns/fn.pixel_price.html).
+    ///   pixels that `rectangle` will occupy. An enough number of tokens can be
+    ///   calculated by multiplying a `rectangle` area and the price of a free
+    ///   pixel. The area can be calculated by multiplying a
+    ///   [width](`Rectangle::width`) & [height](`Rectangle::height`) from
+    ///   `rectangle`. The price of a free pixel can be obtained by
+    ///   [`pixel_price()`](../nft_pixelboard_state/metafns/fn.pixel_price.html).
     ///
     /// On success, returns [`NFTPixelboardEvent::Minted`].
     ///
@@ -248,12 +248,12 @@ pub enum NFTPixelboardAction {
     /// # Requirements
     /// * An NFT must be minted on a pixelboard.
     /// * An NFT must be for sale. This can be found out by
-    /// [`token_info()`]. See also the documentation of
-    /// [`TokenInfo#structfield.pixel_price`].
+    ///   [`token_info()`]. See also the documentation of
+    ///   [`TokenInfo#structfield.pixel_price`].
     /// * [`msg::source()`] must have enough fungible tokens to buy all pixels
-    /// that an NFT occupies. This can be found out by
-    /// [`token_info()`]. See also the documentation of
-    /// [`TokenInfo#structfield.pixel_price`].
+    ///   that an NFT occupies. This can be found out by
+    ///   [`token_info()`]. See also the documentation of
+    ///   [`TokenInfo#structfield.pixel_price`].
     ///
     /// On success, returns [`NFTPixelboardEvent::Bought`].
     ///
@@ -265,14 +265,14 @@ pub enum NFTPixelboardAction {
     ///
     /// There are 3 options of a sale state change:
     /// * Putting up for sale\
-    /// If an NFT is **not** for sale, then assigning `pixel_price` to [`Some`]
-    /// price will transfer it to a pixelboard program & put it up for sale.
+    ///   If an NFT is **not** for sale, then assigning `pixel_price` to [`Some`]
+    ///   price will transfer it to a pixelboard program & put it up for sale.
     /// * Updating a pixel price\
-    /// If an NFT is for sale, then assigning `pixel_price` to [`Some`] price
-    /// will update its pixel price.
+    ///   If an NFT is for sale, then assigning `pixel_price` to [`Some`] price
+    ///   will update its pixel price.
     /// * Removing from sale\
-    /// Assigning the `pixel_price` to [`None`] will transfer an NFT back to its
-    /// owner & remove an NFT from sale.
+    ///   Assigning the `pixel_price` to [`None`] will transfer an NFT back to its
+    ///   owner & remove an NFT from sale.
     ///
     /// **Note:** A commission is included in each NFT resale, so a seller
     /// will receive not all fungible tokens but tokens with a commission
@@ -299,9 +299,9 @@ pub enum NFTPixelboardAction {
     /// * An NFT must be minted on a pixelboard.
     /// * [`msg::source()`](gstd::msg::source) must be the owner of an NFT.
     /// * `painting` length must equal a pixel count in an NFT. The count can be
-    /// calculated by multiplying a [width](`Rectangle::width`) &
-    /// [height](`Rectangle::height`) from a rectangle of the NFT. The NFT
-    /// rectangle can be obtained by [`token_info()`](../nft_pixelboard_state/metafns/fn.token_info.html).
+    ///   calculated by multiplying a [width](`Rectangle::width`) &
+    ///   [height](`Rectangle::height`) from a rectangle of the NFT. The NFT
+    ///   rectangle can be obtained by [`token_info()`](../nft_pixelboard_state/metafns/fn.token_info.html).
     ///
     /// On success, returns [`NFTPixelboardEvent::Painted`].
     Paint {
diff --git a/contracts/nft-pixelboard/tests/utils/pixelboard.rs b/contracts/nft-pixelboard/tests/utils/pixelboard.rs
index fec612f4e..8a9efbc07 100644
--- a/contracts/nft-pixelboard/tests/utils/pixelboard.rs
+++ b/contracts/nft-pixelboard/tests/utils/pixelboard.rs
@@ -121,21 +121,6 @@ impl<'a> NFTPixelboard<'a> {
     }
 }
 
-pub struct NFTPixelboardInit<'a>(InnerProgram<'a>, bool);
-
-impl<'a> NFTPixelboardInit<'a> {
-    #[track_caller]
-    pub fn failed(self) {
-        assert!(self.1)
-    }
-
-    #[track_caller]
-    pub fn succeed(self) -> NFTPixelboard<'a> {
-        assert!(!self.1);
-        NFTPixelboard(self.0)
-    }
-}
-
 // # TODO: uncomment when new meta will be ready for gtest
 
 // pub fn meta_state(&self) -> NFTPixelboardMetaState {
diff --git a/contracts/on-chain-nft/io/src/lib.rs b/contracts/on-chain-nft/io/src/lib.rs
index 875f7c667..996085c17 100644
--- a/contracts/on-chain-nft/io/src/lib.rs
+++ b/contracts/on-chain-nft/io/src/lib.rs
@@ -53,7 +53,7 @@ pub enum OnChainNFTAction {
     /// Arguments:
     /// * `token_metadata` - is a default token metadata from gear-lib.
     /// * `description` - is the vector of layer's item id, where
-    /// the index i is the layer id.
+    ///   the index i is the layer id.
     ///
     /// On success, returns NFTEvent::Mint from gear-lib.
     Mint {
@@ -66,7 +66,7 @@ pub enum OnChainNFTAction {
     ///
     /// Requirements:
     /// * `token_id` MUST exist
-    /// Arguments:
+    ///   Arguments:
     ///
     /// * `token_id` - is the id of the burnt token
     ///
diff --git a/contracts/on-chain-nft/src/lib.rs b/contracts/on-chain-nft/src/lib.rs
index aef36fedd..a4e80e3e3 100644
--- a/contracts/on-chain-nft/src/lib.rs
+++ b/contracts/on-chain-nft/src/lib.rs
@@ -162,8 +162,7 @@ impl OnChainNFTCore for OnChainNFT {
                 .layers
                 .get(&(layer_id as u128))
                 .expect("No such layer")
-                .iter()
-                .nth(*layer_item_id as usize)
+                .get(*layer_item_id as usize)
                 .expect("No such layer item");
             content.push(layer_content.clone());
         }
diff --git a/contracts/staking/tests/utils/common.rs b/contracts/staking/tests/utils/common.rs
index 5cfe234a2..654a4a2a4 100644
--- a/contracts/staking/tests/utils/common.rs
+++ b/contracts/staking/tests/utils/common.rs
@@ -1,6 +1,6 @@
 use convert::identity;
-use gstd::{prelude::*, ActorId};
-use gtest::{Log, Program as InnerProgram, RunResult as InnerRunResult};
+use gstd::prelude::*;
+use gtest::{Log, RunResult as InnerRunResult};
 use marker::PhantomData;
 
 pub trait TransactionalProgram {
diff --git a/contracts/staking/tests/utils/mod.rs b/contracts/staking/tests/utils/mod.rs
index 47f183104..b64b89594 100644
--- a/contracts/staking/tests/utils/mod.rs
+++ b/contracts/staking/tests/utils/mod.rs
@@ -4,7 +4,5 @@ pub use ftoken::*;
 mod common;
 pub use common::*;
 
-pub mod prelude;
-
 pub const FOREIGN_USER: u64 = 12345678;
 pub const PROGRAMS: &[u64] = &[1, 2, 3];
diff --git a/contracts/staking/tests/utils/prelude.rs b/contracts/staking/tests/utils/prelude.rs
deleted file mode 100644
index 9551b8ab4..000000000
--- a/contracts/staking/tests/utils/prelude.rs
+++ /dev/null
@@ -1,2 +0,0 @@
-pub use gstd::prelude::*;
-pub use staking_io::*;
diff --git a/contracts/supply-chain/io/src/lib.rs b/contracts/supply-chain/io/src/lib.rs
index b8a029523..421a9370d 100644
--- a/contracts/supply-chain/io/src/lib.rs
+++ b/contracts/supply-chain/io/src/lib.rs
@@ -96,7 +96,7 @@ pub type ItemId = TokenId;
 ///
 /// # Requirements
 /// - Each [`ActorId`] of `producers`, `distributors`, and `retailers` mustn't
-/// equal [`ActorId::zero()`].
+///   equal [`ActorId::zero()`].
 #[derive(Encode, Decode, Hash, TypeInfo, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Clone)]
 #[codec(crate = gstd::codec)]
 #[scale_info(crate = gstd::scale_info)]
@@ -163,17 +163,17 @@ pub enum InnerAction {
 ///
 /// Important notes:
 /// - Only the last sent asynchronous action for
-/// [`msg::source()`](gstd::msg::source) is cached.
+///   [`msg::source()`](gstd::msg::source) is cached.
 /// - Non-asynchronous actions are never cached.
 /// - There's no guarantee every underprocessed asynchronous action will be
-/// cached. Use
-/// [`is_action_cached()`](../supply_chain_state/metafns/fn.is_action_cached.html)
-/// to check if some action is cached for some [`ActorId`].
+///   cached. Use
+///   [`is_action_cached()`](../supply_chain_state/metafns/fn.is_action_cached.html)
+///   to check if some action is cached for some [`ActorId`].
 /// - It's possible to send a retry action with a different payload, and it'll
-/// continue with it because, for some action, not all payload is saved in the
-/// cache (see [`CachedAction`]).
+///   continue with it because, for some action, not all payload is saved in the
+///   cache (see [`CachedAction`]).
 /// - The cache memory has a limit, so when it's reached every oldest cached
-/// action is replaced with a new one.
+///   action is replaced with a new one.
 #[derive(
     Default, Encode, Decode, TypeInfo, Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Copy, Hash,
 )]
@@ -216,7 +216,7 @@ pub enum ProducerAction {
     /// - The item must exist in a supply chain.
     /// - [`msg::source()`](gstd::msg::source) must be the producer of the item.
     /// - Item's [`ItemState`] must contain [`ItemEventState::Produced`] &
-    /// [`Role::Producer`].
+    ///   [`Role::Producer`].
     ///
     /// On success, replies with [`Event`] where [`ItemState`] contains
     /// [`ItemEventState::ForSale`] & [`Role::Producer`].
@@ -238,7 +238,7 @@ pub enum ProducerAction {
     /// - The item must exist in a supply chain.
     /// - [`msg::source()`](gstd::msg::source) must be the producer of the item.
     /// - Item's [`ItemState`] must contain [`ItemEventState::Produced`] &
-    /// [`Role::Distributor`].
+    ///   [`Role::Distributor`].
     ///
     /// On success, replies with [`Event`] where [`ItemState`] contains
     /// [`ItemEventState::Approved`]/[`ItemEventState::ForSale`] &
@@ -259,7 +259,7 @@ pub enum ProducerAction {
     /// - The item must exist in a supply chain.
     /// - [`msg::source()`](gstd::msg::source) must be the producer of the item.
     /// - Item's [`ItemState`] must contain [`ItemEventState::Approved`] &
-    /// [`Role::Producer`].
+    ///   [`Role::Producer`].
     ///
     /// On success, replies with [`Event`] where [`ItemState`] contains
     /// [`ItemEventState::Shipped`] & [`Role::Producer`].
@@ -286,7 +286,7 @@ pub enum DistributorAction {
     /// - The item must exist in a supply chain.
     /// - [`msg::source()`](gstd::msg::source) must be a distributor.
     /// - Item's [`ItemState`] must contain [`ItemEventState::ForSale`] &
-    /// [`Role::Producer`].
+    ///   [`Role::Producer`].
     ///
     /// On success, replies with [`Event`] where [`ItemState`] contains
     /// [`ItemEventState::Purchased`] & [`Role::Distributor`].
@@ -311,7 +311,7 @@ pub enum DistributorAction {
     /// - The item must exist in a supply chain.
     /// - [`msg::source()`] must be the distributor of the item.
     /// - Item's [`ItemState`] must contain [`ItemEventState::Shipped`] &
-    /// [`Role::Producer`].
+    ///   [`Role::Producer`].
     ///
     /// On success, replies with [`Event`] where [`ItemState`] contains
     /// [`ItemEventState::Received`] & [`Role::Distributor`].
@@ -324,9 +324,9 @@ pub enum DistributorAction {
     /// # Requirements
     /// - The item must exist in a supply chain.
     /// - [`msg::source()`](gstd::msg::source) must be the distributor of the
-    /// item.
+    ///   item.
     /// - Item's [`ItemState`] must contain [`ItemEventState::Received`] &
-    /// [`Role::Distributor`].
+    ///   [`Role::Distributor`].
     ///
     /// On success, replies with [`Event`] where [`ItemState`] contains
     /// [`ItemEventState::Processed`] & [`Role::Distributor`].
@@ -337,9 +337,9 @@ pub enum DistributorAction {
     /// # Requirements
     /// - The item must exist in a supply chain.
     /// - [`msg::source()`](gstd::msg::source) must be the distributor of the
-    /// item.
+    ///   item.
     /// - Item's [`ItemState`] must contain [`ItemEventState::Processed`] &
-    /// [`Role::Distributor`].
+    ///   [`Role::Distributor`].
     ///
     /// On success, replies with [`Event`] where [`ItemState`] contains
     /// [`ItemEventState::Packaged`] & [`Role::Distributor`].
@@ -354,9 +354,9 @@ pub enum DistributorAction {
     /// # Requirements
     /// - The item must exist in a supply chain.
     /// - [`msg::source()`](gstd::msg::source) must be the distributor of the
-    /// item.
+    ///   item.
     /// - Item's [`ItemState`] must contain [`ItemEventState::Packaged`] &
-    /// [`Role::Distributor`].
+    ///   [`Role::Distributor`].
     ///
     /// On success, replies with [`Event`] where [`ItemState`] contains
     /// [`ItemEventState::ForSale`] & [`Role::Distributor`].
@@ -377,9 +377,9 @@ pub enum DistributorAction {
     /// # Requirements
     /// - The item must exist in a supply chain.
     /// - [`msg::source()`](gstd::msg::source) must be the distributor of the
-    /// item.
+    ///   item.
     /// - Item's [`ItemState`] must contain [`ItemEventState::Purchased`] &
-    /// [`Role::Retailer`].
+    ///   [`Role::Retailer`].
     ///
     /// On success, replies with [`Event`] where [`ItemState`] contains
     /// [`ItemEventState::Approved`]/[`ItemEventState::ForSale`] &
@@ -399,9 +399,9 @@ pub enum DistributorAction {
     /// # Requirements
     /// - The item must exist in a supply chain.
     /// - [`msg::source()`](gstd::msg::source) must be the distributor of the
-    /// item.
+    ///   item.
     /// - Item's [`ItemState`] must contain [`ItemEventState::Approved`] &
-    /// [`Role::Distributor`].
+    ///   [`Role::Distributor`].
     ///
     /// On success, replies with [`Event`] where [`ItemState`] contains
     /// [`ItemEventState::Shipped`] & [`Role::Distributor`].
@@ -428,7 +428,7 @@ pub enum RetailerAction {
     /// - The item must exist in a supply chain.
     /// - [`msg::source()`](gstd::msg::source) must be a retailer.
     /// - Item's [`ItemState`] must contain [`ItemEventState::ForSale`] &
-    /// [`Role::Distributor`].
+    ///   [`Role::Distributor`].
     ///
     /// On success, replies with [`Event`] where [`ItemState`] contains
     /// [`ItemEventState::Purchased`] & [`Role::Retailer`].
@@ -454,7 +454,7 @@ pub enum RetailerAction {
     /// - The item must exist in a supply chain.
     /// - [`msg::source()`] must be the retailer of the item.
     /// - Item's [`ItemState`] must contain [`ItemEventState::Shipped`] &
-    /// [`Role::Distributor`].
+    ///   [`Role::Distributor`].
     ///
     /// On success, replies with [`Event`] where [`ItemState`] contains
     /// [`ItemEventState::Received`] & [`Role::Retailer`].
@@ -472,7 +472,7 @@ pub enum RetailerAction {
     /// - The item must exist in a supply chain.
     /// - [`msg::source()`](gstd::msg::source) must be the retailer of the item.
     /// - Item's [`ItemState`] must contain [`ItemEventState::Received`] &
-    /// [`Role::Retailer`].
+    ///   [`Role::Retailer`].
     ///
     /// On success, replies with [`Event`] where [`ItemState`] contains
     /// [`ItemEventState::ForSale`] & [`Role::Retailer`].
@@ -496,7 +496,7 @@ pub enum ConsumerAction {
     /// # Requirements
     /// - The item must exist in a supply chain.
     /// - Item's [`ItemState`] must contain [`ItemEventState::ForSale`] &
-    /// [`Role::Retailer`].
+    ///   [`Role::Retailer`].
     ///
     /// On success, replies with [`Event`] where [`ItemState`] contains
     /// [`ItemEventState::Purchased`] & [`Role::Consumer`].
diff --git a/contracts/syndote/src/strategic_actions.rs b/contracts/syndote/src/strategic_actions.rs
index ce3068e4d..92c2b324a 100644
--- a/contracts/syndote/src/strategic_actions.rs
+++ b/contracts/syndote/src/strategic_actions.rs
@@ -292,11 +292,9 @@ impl Game {
             return;
         }
 
-        let rent = if let Some((_, _, _, rent)) = self.properties[position as usize] {
-            rent
-        } else {
-            0
-        };
+        let (_, _, _, rent) = self.properties[position as usize]
+            .clone()
+            .unwrap_or_default();
         if rent == 0 {
             //    debug!("PENALTY: CELL WITH NO PROPERTIES");
             player_info.penalty += 1;
diff --git a/contracts/varatube/tests/utils.rs b/contracts/varatube/tests/utils.rs
index f5ca81004..4874724bc 100644
--- a/contracts/varatube/tests/utils.rs
+++ b/contracts/varatube/tests/utils.rs
@@ -62,15 +62,11 @@ impl FTokenTestFuncs for Program<'_> {
 
     fn check_balance(&self, account: u64, expected_amount: u128) {
         let state: IoFungibleToken = self.read_state(false).expect("Unable to read token state");
-        let balance = if let Some((_, balance)) = state
+        let (_, balance) = state
             .balances
             .into_iter()
             .find(|(id, _balance)| *id == account.into())
-        {
-            balance
-        } else {
-            0
-        };
+            .unwrap_or_default();
 
         assert_eq!(balance, expected_amount, "Error in balances");
     }