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-spec-v2/src/archive/tests.rs

@@ -27,10 +27,13 @@ use jsonrpsee::{
 	types::{error::CallError, EmptyServerParams as EmptyParams},
 	RpcModule,
 };
-use sc_block_builder::BlockBuilderProvider;
+use sc_block_builder::BlockBuilderBuilder;
 use sp_blockchain::HeaderBackend;
 use sp_consensus::BlockOrigin;
-use sp_runtime::SaturatedConversion;
+use sp_runtime::{
+	traits::{Block as BlockT, Header as HeaderT},
+	SaturatedConversion,
+};
 use std::sync::Arc;
 use substrate_test_runtime::Transfer;
 use substrate_test_runtime_client::{
@@ -72,7 +75,12 @@ async fn archive_body() {
 	assert!(res.is_none());
 
 	// Import a new block with an extrinsic.
-	let mut builder = client.new_block(Default::default()).unwrap();
+	let mut builder = BlockBuilderBuilder::new(&*client)
+		.on_parent_block(client.chain_info().genesis_hash)
+		.with_parent_block_number(0)
+		.build()
+		.unwrap();
+
 	builder
 		.push_transfer(runtime::Transfer {
 			from: AccountKeyring::Alice.into(),
@@ -101,7 +109,12 @@ async fn archive_header() {
 	assert!(res.is_none());
 
 	// Import a new block with an extrinsic.
-	let mut builder = client.new_block(Default::default()).unwrap();
+	let mut builder = BlockBuilderBuilder::new(&*client)
+		.on_parent_block(client.chain_info().genesis_hash)
+		.with_parent_block_number(0)
+		.build()
+		.unwrap();
+
 	builder
 		.push_transfer(runtime::Transfer {
 			from: AccountKeyring::Alice.into(),
@@ -147,24 +160,57 @@ async fn archive_hash_by_height() {
 	//                          ^^^ h = N
 	//                                     ^^^ h =  N + 1
 	//                                                 ^^^ h = N + 2
-	let finalized = client.new_block(Default::default()).unwrap().build().unwrap().block;
+	let finalized = BlockBuilderBuilder::new(&*client)
+		.on_parent_block(client.chain_info().genesis_hash)
+		.with_parent_block_number(0)
+		.build()
+		.unwrap()
+		.build()
+		.unwrap()
+		.block;
 	let finalized_hash = finalized.header.hash();
 	client.import(BlockOrigin::Own, finalized.clone()).await.unwrap();
 	client.finalize_block(finalized_hash, None).unwrap();
 
-	let block_1 = client.new_block(Default::default()).unwrap().build().unwrap().block;
+	let block_1 = BlockBuilderBuilder::new(&*client)
+		.on_parent_block(finalized.hash())
+		.with_parent_block_number(*finalized.header().number())
+		.build()
+		.unwrap()
+		.build()
+		.unwrap()
+		.block;
 	let block_1_hash = block_1.header.hash();
 	client.import(BlockOrigin::Own, block_1.clone()).await.unwrap();
 
-	let block_2 = client.new_block(Default::default()).unwrap().build().unwrap().block;
+	let block_2 = BlockBuilderBuilder::new(&*client)
+		.on_parent_block(block_1.hash())
+		.with_parent_block_number(*block_1.header().number())
+		.build()
+		.unwrap()
+		.build()
+		.unwrap()
+		.block;
 	let block_2_hash = block_2.header.hash();
 	client.import(BlockOrigin::Own, block_2.clone()).await.unwrap();
-	let block_3 = client.new_block(Default::default()).unwrap().build().unwrap().block;
+	let block_3 = BlockBuilderBuilder::new(&*client)
+		.on_parent_block(block_2.hash())
+		.with_parent_block_number(*block_2.header().number())
+		.build()
+		.unwrap()
+		.build()
+		.unwrap()
+		.block;
 	let block_3_hash = block_3.header.hash();
 	client.import(BlockOrigin::Own, block_3.clone()).await.unwrap();
 
 	// Import block 4 fork.
-	let mut block_builder = client.new_block_at(block_1_hash, Default::default(), false).unwrap();
+	let mut block_builder = BlockBuilderBuilder::new(&*client)
+		.on_parent_block(block_1_hash)
+		.with_parent_block_number(*block_1.header().number())
+		.build()
+		.unwrap();
+
 	// This push is required as otherwise block 3 has the same hash as block 1 and won't get
 	// imported
 	block_builder
@@ -238,7 +284,14 @@ async fn archive_call() {
 		.unwrap();
 	assert_matches!(result, MethodResult::Err(_));
 
-	let block_1 = client.new_block(Default::default()).unwrap().build().unwrap().block;
+	let block_1 = BlockBuilderBuilder::new(&*client)
+		.on_parent_block(client.chain_info().genesis_hash)
+		.with_parent_block_number(0)
+		.build()
+		.unwrap()
+		.build()
+		.unwrap()
+		.block;
 	let block_1_hash = block_1.header.hash();
 	client.import(BlockOrigin::Own, block_1.clone()).await.unwrap();