sc-block-builder: Remove BlockBuilderProvider (#2099)

The `BlockBuilderProvider` was a trait that was defined in
`sc-block-builder`. The trait was implemented for `Client`. This
basically meant that you needed to import `sc-block-builder` any way to
have access to the block builder. So, this trait was not providing any
real value. This pull request is removing the said trait. Instead of the
trait it introduces a builder for creating a `BlockBuilder`. The builder
currently has the quite fabulous name `BlockBuilderBuilder` (I'm open to
any better name 😅). The rest of the pull request is about
replacing the old trait with the new builder.

# Downstream code changes

If you used `new_block` or `new_block_at` before you now need to switch
it over to the new `BlockBuilderBuilder` pattern:

```rust
// `new` requires a type that implements `CallApiAt`. 
let mut block_builder = BlockBuilderBuilder::new(client)
                // Then you need to specify the hash of the parent block the block will be build on top of
		.on_parent_block(at)
                // The block builder also needs the block number of the parent block. 
                // Here it is fetched from the given `client` using the `HeaderBackend`
                // However, there also exists `with_parent_block_number` for directly passing the number
		.fetch_parent_block_number(client)
		.unwrap()
                // Enable proof recording if required. This call is optional.
		.enable_proof_recording()
                // Pass the digests. This call is optional.
                .with_inherent_digests(digests)
		.build()
		.expect("Creates new block builder");
```

---------

Co-authored-by: Sebastian Kunert <skunert49@gmail.com>
Co-authored-by: command-bot <>

substrate/client/rpc/src/chain/tests.rs

@@ -20,7 +20,7 @@ use super::*;
 use crate::testing::{test_executor, timeout_secs};
 use assert_matches::assert_matches;
 use jsonrpsee::types::EmptyServerParams as EmptyParams;
-use sc_block_builder::BlockBuilderProvider;
+use sc_block_builder::BlockBuilderBuilder;
 use sp_consensus::BlockOrigin;
 use sp_rpc::list::ListOrValue;
 use substrate_test_runtime_client::{
@@ -75,7 +75,14 @@ async fn should_return_a_block() {
 	let mut client = Arc::new(substrate_test_runtime_client::new());
 	let api = new_full(client.clone(), test_executor()).into_rpc();
 
-	let block = client.new_block(Default::default()).unwrap().build().unwrap().block;
+	let block = BlockBuilderBuilder::new(&*client)
+		.on_parent_block(client.chain_info().best_hash)
+		.with_parent_block_number(client.chain_info().best_number)
+		.build()
+		.unwrap()
+		.build()
+		.unwrap()
+		.block;
 	let block_hash = block.hash();
 	client.import(BlockOrigin::Own, block).await.unwrap();
 
@@ -152,7 +159,14 @@ async fn should_return_block_hash() {
 		api.call("chain_getBlockHash", [ListOrValue::from(1_u64)]).await.unwrap();
 	assert_matches!(res, None);
 
-	let block = client.new_block(Default::default()).unwrap().build().unwrap().block;
+	let block = BlockBuilderBuilder::new(&*client)
+		.on_parent_block(client.chain_info().best_hash)
+		.with_parent_block_number(client.chain_info().best_number)
+		.build()
+		.unwrap()
+		.build()
+		.unwrap()
+		.block;
 	client.import(BlockOrigin::Own, block.clone()).await.unwrap();
 
 	let res: ListOrValue<Option<H256>> =
@@ -197,7 +211,14 @@ async fn should_return_finalized_hash() {
 	assert_eq!(res, client.genesis_hash());
 
 	// import new block
-	let block = client.new_block(Default::default()).unwrap().build().unwrap().block;
+	let block = BlockBuilderBuilder::new(&*client)
+		.on_parent_block(client.chain_info().best_hash)
+		.with_parent_block_number(client.chain_info().best_number)
+		.build()
+		.unwrap()
+		.build()
+		.unwrap()
+		.block;
 	let block_hash = block.hash();
 	client.import(BlockOrigin::Own, block).await.unwrap();
 
@@ -232,7 +253,14 @@ async fn test_head_subscription(method: &str) {
 	let mut sub = {
 		let api = new_full(client.clone(), test_executor()).into_rpc();
 		let sub = api.subscribe(method, EmptyParams::new()).await.unwrap();
-		let block = client.new_block(Default::default()).unwrap().build().unwrap().block;
+		let block = BlockBuilderBuilder::new(&*client)
+			.on_parent_block(client.chain_info().best_hash)
+			.with_parent_block_number(client.chain_info().best_number)
+			.build()
+			.unwrap()
+			.build()
+			.unwrap()
+			.block;
 		let block_hash = block.hash();
 		client.import(BlockOrigin::Own, block).await.unwrap();
 		client.finalize_block(block_hash, None).unwrap();

substrate/client/rpc/src/dev/tests.rs

@@ -17,7 +17,7 @@
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
 use super::*;
-use sc_block_builder::BlockBuilderProvider;
+use sc_block_builder::BlockBuilderBuilder;
 use sp_blockchain::HeaderBackend;
 use sp_consensus::BlockOrigin;
 use substrate_test_runtime_client::{prelude::*, runtime::Block};
@@ -27,7 +27,14 @@ async fn block_stats_work() {
 	let mut client = Arc::new(substrate_test_runtime_client::new());
 	let api = <Dev<Block, _>>::new(client.clone(), DenyUnsafe::No).into_rpc();
 
-	let block = client.new_block(Default::default()).unwrap().build().unwrap().block;
+	let block = BlockBuilderBuilder::new(&*client)
+		.on_parent_block(client.chain_info().genesis_hash)
+		.with_parent_block_number(0)
+		.build()
+		.unwrap()
+		.build()
+		.unwrap()
+		.block;
 
 	let (expected_witness_len, expected_witness_compact_len, expected_block_len) = {
 		let genesis_hash = client.chain_info().genesis_hash;
@@ -72,7 +79,14 @@ async fn deny_unsafe_works() {
 	let mut client = Arc::new(substrate_test_runtime_client::new());
 	let api = <Dev<Block, _>>::new(client.clone(), DenyUnsafe::Yes).into_rpc();
 
-	let block = client.new_block(Default::default()).unwrap().build().unwrap().block;
+	let block = BlockBuilderBuilder::new(&*client)
+		.on_parent_block(client.chain_info().genesis_hash)
+		.with_parent_block_number(0)
+		.build()
+		.unwrap()
+		.build()
+		.unwrap()
+		.block;
 	client.import(BlockOrigin::Own, block).await.unwrap();
 
 	let best_hash = client.info().best_hash;

substrate/client/rpc/src/state/tests.rs

@@ -25,7 +25,7 @@ use jsonrpsee::{
 	core::Error as RpcError,
 	types::{error::CallError as RpcCallError, EmptyServerParams as EmptyParams, ErrorObject},
 };
-use sc_block_builder::BlockBuilderProvider;
+use sc_block_builder::BlockBuilderBuilder;
 use sc_rpc_api::DenyUnsafe;
 use sp_consensus::BlockOrigin;
 use sp_core::{hash::H256, storage::ChildInfo};
@@ -218,7 +218,11 @@ async fn should_notify_about_storage_changes() {
 		let sub = api_rpc.subscribe("state_subscribeStorage", EmptyParams::new()).await.unwrap();
 
 		// Cause a change:
-		let mut builder = client.new_block(Default::default()).unwrap();
+		let mut builder = BlockBuilderBuilder::new(&*client)
+			.on_parent_block(client.chain_info().best_hash)
+			.with_parent_block_number(client.chain_info().best_number)
+			.build()
+			.unwrap();
 		builder
 			.push_transfer(Transfer {
 				from: AccountKeyring::Alice.into(),
@@ -263,7 +267,11 @@ async fn should_send_initial_storage_changes_and_notifications() {
 			.await
 			.unwrap();
 
-		let mut builder = client.new_block(Default::default()).unwrap();
+		let mut builder = BlockBuilderBuilder::new(&*client)
+			.on_parent_block(client.chain_info().best_hash)
+			.with_parent_block_number(client.chain_info().best_number)
+			.build()
+			.unwrap();
 		builder
 			.push_transfer(Transfer {
 				from: AccountKeyring::Alice.into(),
@@ -291,7 +299,11 @@ async fn should_query_storage() {
 		let (api, _child) = new_full(client.clone(), test_executor(), DenyUnsafe::No);
 
 		let mut add_block = |index| {
-			let mut builder = client.new_block(Default::default()).unwrap();
+			let mut builder = BlockBuilderBuilder::new(&*client)
+				.on_parent_block(client.chain_info().best_hash)
+				.with_parent_block_number(client.chain_info().best_number)
+				.build()
+				.unwrap();
 			// fake change: None -> None -> None
 			builder
 				.push(ExtrinsicBuilder::new_storage_change(vec![1], None).build())