RPC to query transaction fee + weight + info (#3876)

* initial version for testing

* New version that compiles

* optional at block parameter

* Fix some more view grumbles.

* Update srml/transaction-payment/src/lib.rs

substrate/node/rpc/Cargo.toml

@@ -8,7 +8,9 @@ edition = "2018"
 client = { package = "substrate-client", path = "../../core/client" }
 jsonrpc-core = "13.2.0"
 node-primitives = { path = "../primitives" }
+node-runtime = { path = "../runtime" }
 sr-primitives = { path = "../../core/sr-primitives" }
 srml-contracts-rpc = { path = "../../srml/contracts/rpc/" }
+srml-transaction-payment-rpc = { path = "../../srml/transaction-payment/rpc/" }
 srml-system-rpc = { path = "../../srml/system/rpc/" }
 transaction_pool = { package = "substrate-transaction-pool", path = "../../core/transaction-pool" }

substrate/node/rpc/src/lib.rs

@@ -32,6 +32,7 @@
 use std::sync::Arc;
 
 use node_primitives::{Block, AccountId, Index, Balance};
+use node_runtime::UncheckedExtrinsic;
 use sr_primitives::traits::ProvideRuntimeApi;
 use transaction_pool::txpool::{ChainApi, Pool};
 
@@ -42,18 +43,23 @@ pub fn create<C, P, M>(client: Arc<C>, pool: Arc<Pool<P>>) -> jsonrpc_core::IoHa
 	C: Send + Sync + 'static,
 	C::Api: srml_system_rpc::AccountNonceApi<Block, AccountId, Index>,
 	C::Api: srml_contracts_rpc::ContractsRuntimeApi<Block, AccountId, Balance>,
+	C::Api: srml_transaction_payment_rpc::TransactionPaymentRuntimeApi<Block, Balance, UncheckedExtrinsic>,
 	P: ChainApi + Sync + Send + 'static,
 	M: jsonrpc_core::Metadata + Default,
 {
 	use srml_system_rpc::{System, SystemApi};
 	use srml_contracts_rpc::{Contracts, ContractsApi};
+	use srml_transaction_payment_rpc::{TransactionPayment, TransactionPaymentApi};
 
 	let mut io = jsonrpc_core::IoHandler::default();
 	io.extend_with(
 		SystemApi::to_delegate(System::new(client.clone(), pool))
 	);
 	io.extend_with(
-		ContractsApi::to_delegate(Contracts::new(client))
+		ContractsApi::to_delegate(Contracts::new(client.clone()))
+	);
+	io.extend_with(
+		TransactionPaymentApi::to_delegate(TransactionPayment::new(client))
 	);
 	io
 }

substrate/node/runtime/Cargo.toml

@@ -52,6 +52,7 @@ timestamp = { package = "srml-timestamp", path = "../../srml/timestamp", default
 treasury = { package = "srml-treasury", path = "../../srml/treasury", default-features = false }
 utility = { package = "srml-utility", path = "../../srml/utility", default-features = false }
 transaction-payment = { package = "srml-transaction-payment", path = "../../srml/transaction-payment", default-features = false }
+transaction-payment-rpc-runtime-api = { package = "srml-transaction-payment-rpc-runtime-api", path = "../../srml/transaction-payment/rpc/runtime-api/", default-features = false }
 
 [build-dependencies]
 wasm-builder-runner = { package = "substrate-wasm-builder-runner", version = "1.0.4", path = "../../core/utils/wasm-builder-runner" }
@@ -103,5 +104,6 @@ std = [
 	"treasury/std",
 	"utility/std",
 	"transaction-payment/std",
+	"transaction-payment-rpc-runtime-api/std",
 	"version/std",
 ]

substrate/node/runtime/src/lib.rs

@@ -50,6 +50,8 @@ use version::NativeVersion;
 use primitives::OpaqueMetadata;
 use grandpa::{AuthorityId as GrandpaId, AuthorityWeight as GrandpaWeight};
 use im_online::sr25519::{AuthorityId as ImOnlineId};
+use transaction_payment_rpc_runtime_api::RuntimeDispatchInfo;
+use contracts_rpc_runtime_api::ContractExecResult;
 use system::offchain::TransactionSubmitter;
 
 #[cfg(any(feature = "std", test))]
@@ -661,9 +663,7 @@ impl_runtime_apis! {
 			value: Balance,
 			gas_limit: u64,
 			input_data: Vec<u8>,
-		) -> contracts_rpc_runtime_api::ContractExecResult {
-			use contracts_rpc_runtime_api::ContractExecResult;
-
+		) -> ContractExecResult {
 			let exec_result = Contracts::bare_call(
 				origin,
 				dest.into(),
@@ -681,9 +681,20 @@ impl_runtime_apis! {
 		}
 	}
 
+	impl transaction_payment_rpc_runtime_api::TransactionPaymentApi<
+		Block,
+		Balance,
+		UncheckedExtrinsic,
+	> for Runtime {
+		fn query_info(uxt: UncheckedExtrinsic, len: u32) -> RuntimeDispatchInfo<Balance> {
+			TransactionPayment::query_info(uxt, len)
+		}
+	}
+
 	impl substrate_session::SessionKeys<Block> for Runtime {
 		fn generate_session_keys(seed: Option<Vec<u8>>) -> Vec<u8> {
-			let seed = seed.as_ref().map(|s| rstd::str::from_utf8(&s).expect("Seed is an utf8 string"));
+			let seed = seed.as_ref().map(|s| rstd::str::from_utf8(&s)
+				.expect("Seed is an utf8 string"));
 			SessionKeys::generate(seed)
 		}
 	}