Expose types from sc-service (paritytech#5855)

# Description

At moonbeam we have worked on a `lazy-loading` feature which is a client
mode that forks a live parachain and fetches its state on-demand, we
have been able to do this by duplicating some code from
`sc_service::client`. The objective of this PR is to simplify the
implementation by making public some types in polkadot-sdk.

- Modules:
- `sc_service::client` **I do not see a point to only expose this type
when `test-helpers` feature is enabled**

## Integration

Not applicable, the PR just makes some types public.

## Review Notes

The changes included in this PR give more flexibility for client
developers by exposing important types.

Author: RomarQ

prdoc/pr_5855.prdoc

@@ -0,0 +1,15 @@
+# Schema: Polkadot SDK PRDoc Schema (prdoc) v1.0.0
+# See doc at https://raw.githubusercontent.com/paritytech/polkadot-sdk/master/prdoc/schema_user.json
+
+title: Remove feature `test-helpers` from sc-service
+
+doc:
+  - audience: Node Dev
+    description: |
+      Removes feature `test-helpers` from sc-service.
+
+crates:
+  - name: sc-service
+    bump: major
+  - name: sc-rpc-spec-v2
+    bump: major

substrate/bin/node/testing/Cargo.toml

@@ -37,7 +37,7 @@ sc-client-api = { workspace = true, default-features = true }
 sc-client-db = { features = ["rocksdb"], workspace = true, default-features = true }
 sc-consensus = { workspace = true, default-features = true }
 sc-executor = { workspace = true, default-features = true }
-sc-service = { features = ["rocksdb", "test-helpers"], workspace = true, default-features = true }
+sc-service = { features = ["rocksdb"], workspace = true, default-features = true }
 sp-api = { workspace = true, default-features = true }
 sp-block-builder = { workspace = true, default-features = true }
 sp-blockchain = { workspace = true, default-features = true }

substrate/client/network/test/Cargo.toml

@@ -33,7 +33,7 @@ sc-network-types = { workspace = true, default-features = true }
 sc-utils = { workspace = true, default-features = true }
 sc-network-light = { workspace = true, default-features = true }
 sc-network-sync = { workspace = true, default-features = true }
-sc-service = { features = ["test-helpers"], workspace = true }
+sc-service = { workspace = true }
 sp-blockchain = { workspace = true, default-features = true }
 sp-consensus = { workspace = true, default-features = true }
 sp-core = { workspace = true, default-features = true }

substrate/client/rpc-spec-v2/Cargo.toml

@@ -56,7 +56,7 @@ sp-consensus = { workspace = true, default-features = true }
 sp-externalities = { workspace = true, default-features = true }
 sp-maybe-compressed-blob = { workspace = true, default-features = true }
 sc-block-builder = { workspace = true, default-features = true }
-sc-service = { features = ["test-helpers"], workspace = true, default-features = true }
+sc-service = { workspace = true, default-features = true }
 sc-rpc = { workspace = true, default-features = true, features = ["test-helpers"] }
 assert_matches = { workspace = true }
 pretty_assertions = { workspace = true }

substrate/client/rpc-spec-v2/src/chain_head/subscription/inner.rs

@@ -784,7 +784,7 @@ mod tests {
 	use super::*;
 	use jsonrpsee::ConnectionId;
 	use sc_block_builder::BlockBuilderBuilder;
-	use sc_service::client::new_in_mem;
+	use sc_service::client::new_with_backend;
 	use sp_consensus::BlockOrigin;
 	use sp_core::{testing::TaskExecutor, H256};
 	use substrate_test_runtime_client::{
@@ -811,13 +811,13 @@ mod tests {
 		)
 		.unwrap();
 		let client = Arc::new(
-			new_in_mem::<_, Block, _, RuntimeApi>(
+			new_with_backend::<_, _, Block, _, RuntimeApi>(
 				backend.clone(),
 				executor,
 				genesis_block_builder,
+				Box::new(TaskExecutor::new()),
 				None,
 				None,
-				Box::new(TaskExecutor::new()),
 				client_config,
 			)
 			.unwrap(),

substrate/client/rpc-spec-v2/src/chain_head/tests.rs

@@ -34,7 +34,7 @@ use jsonrpsee::{
 use sc_block_builder::BlockBuilderBuilder;
 use sc_client_api::ChildInfo;
 use sc_rpc::testing::TokioTestExecutor;
-use sc_service::client::new_in_mem;
+use sc_service::client::new_with_backend;
 use sp_blockchain::HeaderBackend;
 use sp_consensus::BlockOrigin;
 use sp_core::{
@@ -2547,13 +2547,13 @@ async fn pin_block_references() {
 	.unwrap();
 
 	let client = Arc::new(
-		new_in_mem::<_, Block, _, RuntimeApi>(
+		new_with_backend::<_, _, Block, _, RuntimeApi>(
 			backend.clone(),
 			executor,
 			genesis_block_builder,
+			Box::new(TokioTestExecutor::default()),
 			None,
 			None,
-			Box::new(TokioTestExecutor::default()),
 			client_config,
 		)
 		.unwrap(),

substrate/client/service/Cargo.toml

@@ -20,8 +20,6 @@ default = ["rocksdb"]
 # The RocksDB feature activates the RocksDB database backend. If it is not activated, and you pass
 # a path to a database, an error will be produced at runtime.
 rocksdb = ["sc-client-db/rocksdb"]
-# exposes the client type
-test-helpers = []
 runtime-benchmarks = [
 	"sc-client-db/runtime-benchmarks",
 	"sp-runtime/runtime-benchmarks",

substrate/client/service/src/client/client.rs

@@ -85,10 +85,8 @@ use std::{
 	sync::Arc,
 };
 
-#[cfg(feature = "test-helpers")]
-use {
-	super::call_executor::LocalCallExecutor, sc_client_api::in_mem, sp_core::traits::CodeExecutor,
-};
+use super::call_executor::LocalCallExecutor;
+use sp_core::traits::CodeExecutor;
 
 type NotificationSinks<T> = Mutex<Vec<TracingUnboundedSender<T>>>;
 
@@ -152,39 +150,6 @@ enum PrepareStorageChangesResult<Block: BlockT> {
 	Discard(ImportResult),
 	Import(Option<sc_consensus::StorageChanges<Block>>),
 }
-
-/// Create an instance of in-memory client.
-#[cfg(feature = "test-helpers")]
-pub fn new_in_mem<E, Block, G, RA>(
-	backend: Arc<in_mem::Backend<Block>>,
-	executor: E,
-	genesis_block_builder: G,
-	prometheus_registry: Option<Registry>,
-	telemetry: Option<TelemetryHandle>,
-	spawn_handle: Box<dyn SpawnNamed>,
-	config: ClientConfig<Block>,
-) -> sp_blockchain::Result<
-	Client<in_mem::Backend<Block>, LocalCallExecutor<Block, in_mem::Backend<Block>, E>, Block, RA>,
->
-where
-	E: CodeExecutor + sc_executor::RuntimeVersionOf,
-	Block: BlockT,
-	G: BuildGenesisBlock<
-			Block,
-			BlockImportOperation = <in_mem::Backend<Block> as backend::Backend<Block>>::BlockImportOperation,
-		>,
-{
-	new_with_backend(
-		backend,
-		executor,
-		genesis_block_builder,
-		spawn_handle,
-		prometheus_registry,
-		telemetry,
-		config,
-	)
-}
-
 /// Client configuration items.
 #[derive(Debug, Clone)]
 pub struct ClientConfig<Block: BlockT> {
@@ -218,7 +183,6 @@ impl<Block: BlockT> Default for ClientConfig<Block> {
 
 /// Create a client with the explicitly provided backend.
 /// This is useful for testing backend implementations.
-#[cfg(feature = "test-helpers")]
 pub fn new_with_backend<B, E, Block, G, RA>(
 	backend: Arc<B>,
 	executor: E,

substrate/client/service/src/client/mod.rs

@@ -56,5 +56,4 @@ pub use call_executor::LocalCallExecutor;
 pub use client::{Client, ClientConfig};
 pub(crate) use code_provider::CodeProvider;
 
-#[cfg(feature = "test-helpers")]
-pub use self::client::{new_in_mem, new_with_backend};
+pub use self::client::new_with_backend;

substrate/client/service/src/lib.rs

@@ -23,14 +23,11 @@
 #![recursion_limit = "1024"]
 
 pub mod chain_ops;
+pub mod client;
 pub mod config;
 pub mod error;
 
 mod builder;
-#[cfg(feature = "test-helpers")]
-pub mod client;
-#[cfg(not(feature = "test-helpers"))]
-mod client;
 mod metrics;
 mod task_manager;