Make use of NLL in client crate (#1436)

* fix: set edition to 2018 in Cargo.toml.

* fix: refactor function to make use of NLL.

* fix: result of applying 'cargo fix --edition' command.

* fix: removes extern crate

* fix: remove module uses from lib.rs

* fix: tests imports

substrate/core/client/src/light/backend.rs

@@ -25,12 +25,12 @@ use runtime_primitives::{generic::BlockId, Justification, StorageMap, ChildrenSt
 use state_machine::{Backend as StateBackend, InMemoryChangesTrieStorage, TrieBackend};
 use runtime_primitives::traits::{Block as BlockT, NumberFor, AuthorityIdFor};
 
-use in_mem;
-use backend::{AuxStore, Backend as ClientBackend, BlockImportOperation, RemoteBackend, NewBlockState};
-use blockchain::HeaderBackend as BlockchainHeaderBackend;
-use error::{Error as ClientError, ErrorKind as ClientErrorKind, Result as ClientResult};
-use light::blockchain::{Blockchain, Storage as BlockchainStorage};
-use light::fetcher::{Fetcher, RemoteReadRequest};
+use crate::in_mem;
+use crate::backend::{AuxStore, Backend as ClientBackend, BlockImportOperation, RemoteBackend, NewBlockState};
+use crate::blockchain::HeaderBackend as BlockchainHeaderBackend;
+use crate::error::{Error as ClientError, ErrorKind as ClientErrorKind, Result as ClientResult};
+use crate::light::blockchain::{Blockchain, Storage as BlockchainStorage};
+use crate::light::fetcher::{Fetcher, RemoteReadRequest};
 use hash_db::Hasher;
 use trie::MemoryDB;
 use heapsize::HeapSizeOf;

substrate/core/client/src/light/blockchain.rs

@@ -24,12 +24,12 @@ use parking_lot::Mutex;
 use runtime_primitives::{Justification, generic::BlockId};
 use runtime_primitives::traits::{Block as BlockT, Header as HeaderT, NumberFor, Zero, AuthorityIdFor};
 
-use backend::{AuxStore, NewBlockState};
-use blockchain::{Backend as BlockchainBackend, BlockStatus, Cache as BlockchainCache,
+use crate::backend::{AuxStore, NewBlockState};
+use crate::blockchain::{Backend as BlockchainBackend, BlockStatus, Cache as BlockchainCache,
 	HeaderBackend as BlockchainHeaderBackend, Info as BlockchainInfo};
-use cht;
-use error::{ErrorKind as ClientErrorKind, Result as ClientResult};
-use light::fetcher::{Fetcher, RemoteHeaderRequest};
+use crate::cht;
+use crate::error::{ErrorKind as ClientErrorKind, Result as ClientResult};
+use crate::light::fetcher::{Fetcher, RemoteHeaderRequest};
 
 /// Light client blockchain storage.
 pub trait Storage<Block: BlockT>: AuxStore + BlockchainHeaderBackend<Block> {
@@ -166,8 +166,8 @@ impl<S, F, Block> BlockchainBackend<Block> for Blockchain<S, F> where Block: Blo
 pub mod tests {
 	use std::collections::HashMap;
 	use test_client::runtime::{Hash, Block, Header};
-	use blockchain::Info;
-	use light::fetcher::tests::OkCallFetcher;
+	use crate::blockchain::Info;
+	use crate::light::fetcher::tests::OkCallFetcher;
 	use super::*;
 
 	pub type DummyBlockchain = Blockchain<DummyStorage, OkCallFetcher>;

substrate/core/client/src/light/call_executor.rs

@@ -22,7 +22,7 @@ use std::marker::PhantomData;
 use std::sync::Arc;
 use futures::{IntoFuture, Future};
 
-use codec::Encode;
+use codec::{Encode, Decode};
 use primitives::{H256, Blake2Hasher, convert_hash};
 use runtime_primitives::generic::BlockId;
 use runtime_primitives::traits::{As, Block as BlockT, Header as HeaderT};
@@ -30,12 +30,11 @@ use state_machine::{self, Backend as StateBackend, CodeExecutor, OverlayedChange
 	create_proof_check_backend, execution_proof_check_on_trie_backend, ExecutionManager};
 use hash_db::Hasher;
 
-use blockchain::Backend as ChainBackend;
-use call_executor::CallExecutor;
-use error::{Error as ClientError, ErrorKind as ClientErrorKind, Result as ClientResult};
-use light::fetcher::{Fetcher, RemoteCallRequest};
+use crate::blockchain::Backend as ChainBackend;
+use crate::call_executor::CallExecutor;
+use crate::error::{Error as ClientError, ErrorKind as ClientErrorKind, Result as ClientResult};
+use crate::light::fetcher::{Fetcher, RemoteCallRequest};
 use executor::{RuntimeVersion, NativeVersion};
-use codec::Decode;
 use heapsize::HeapSizeOf;
 use trie::MemoryDB;
 

substrate/core/client/src/light/fetcher.rs

@@ -28,10 +28,10 @@ use runtime_primitives::traits::{As, Block as BlockT, Header as HeaderT, NumberF
 use state_machine::{CodeExecutor, ChangesTrieRootsStorage, ChangesTrieAnchorBlockId,
 	TrieBackend, read_proof_check, key_changes_proof_check, create_proof_check_backend_storage};
 
-use cht;
-use error::{Error as ClientError, ErrorKind as ClientErrorKind, Result as ClientResult};
-use light::blockchain::{Blockchain, Storage as BlockchainStorage};
-use light::call_executor::check_execution_proof;
+use crate::cht;
+use crate::error::{Error as ClientError, ErrorKind as ClientErrorKind, Result as ClientResult};
+use crate::light::blockchain::{Blockchain, Storage as BlockchainStorage};
+use crate::light::call_executor::check_execution_proof;
 
 /// Remote call request.
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
@@ -391,17 +391,17 @@ pub mod tests {
 	use futures::future::{ok, err, FutureResult};
 	use parking_lot::Mutex;
 	use keyring::Keyring;
-	use client::tests::prepare_client_with_key_changes;
+	use crate::client::tests::prepare_client_with_key_changes;
 	use executor::{self, NativeExecutionDispatch};
-	use error::Error as ClientError;
+	use crate::error::Error as ClientError;
 	use test_client::{self, TestClient, blockchain::HeaderBackend};
 	use test_client::runtime::{self, Hash, Block, Header};
 	use consensus::BlockOrigin;
 
-	use in_mem::{Blockchain as InMemoryBlockchain};
-	use light::fetcher::{Fetcher, FetchChecker, LightDataChecker,
+	use crate::in_mem::{Blockchain as InMemoryBlockchain};
+	use crate::light::fetcher::{Fetcher, FetchChecker, LightDataChecker,
 		RemoteCallRequest, RemoteHeaderRequest};
-	use light::blockchain::tests::{DummyStorage, DummyBlockchain};
+	use crate::light::blockchain::tests::{DummyStorage, DummyBlockchain};
 	use primitives::{twox_128, Blake2Hasher};
 	use primitives::storage::well_known_keys;
 	use runtime_primitives::generic::BlockId;
@@ -454,7 +454,7 @@ pub mod tests {
 			remote_block_header.clone(),
 			None,
 			None,
-			::backend::NewBlockState::Final,
+			crate::backend::NewBlockState::Final,
 		).unwrap();
 		let local_executor = test_client::LocalExecutor::new();
 		let local_checker = LightDataChecker::new(Arc::new(DummyBlockchain::new(DummyStorage::new())), local_executor);

substrate/core/client/src/light/mod.rs

@@ -28,12 +28,12 @@ use runtime_primitives::BuildStorage;
 use runtime_primitives::traits::Block as BlockT;
 use state_machine::{CodeExecutor, ExecutionStrategy};
 
-use client::Client;
-use error::Result as ClientResult;
-use light::backend::Backend;
-use light::blockchain::{Blockchain, Storage as BlockchainStorage};
-use light::call_executor::RemoteCallExecutor;
-use light::fetcher::{Fetcher, LightDataChecker};
+use crate::client::Client;
+use crate::error::Result as ClientResult;
+use crate::light::backend::Backend;
+use crate::light::blockchain::{Blockchain, Storage as BlockchainStorage};
+use crate::light::call_executor::RemoteCallExecutor;
+use crate::light::fetcher::{Fetcher, LightDataChecker};
 use hash_db::Hasher;
 
 /// Create an instance of light client blockchain backend.