test-utils: test executor, backend and function to create test client (…

…paritytech#73)

* test-utils: basic executor and backend definitions

* test-utils: implement function to create a new test client

* Fix indentation

Cargo.toml

@@ -6,6 +6,7 @@ members = [
 	"rpc/primitives",
 	"template/node",
 	"template/runtime",
+	"template/test-utils/client",
 ]
 exclude = ["vendor"]
 

template/test-utils/client/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "frontier-template-test-client"
+version = "0.1.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+edition = "2018"
+description = "Ethereum RPC (web3) compatibility layer for Substrate."
+license = "GPL-3.0"
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "1.3.1" }
+sp-runtime = { path = "../../../vendor/substrate/primitives/runtime" }
+sp-api = { path = "../../../vendor/substrate/primitives/api" }
+sc-executor = { path = "../../../vendor/substrate/client/executor" }
+sc-light = { path = "../../../vendor/substrate/client/light" }
+sc-consensus = { path = "../../../vendor/substrate/client/consensus/common" }
+sc-client-api = { path = "../../../vendor/substrate/client/api" }
+substrate-test-client = { path = "../../../vendor/substrate/test-utils/client" }
+frontier-template-runtime = { path = "../../runtime" }

template/test-utils/client/src/lib.rs

@@ -0,0 +1,110 @@
+use std::sync::Arc;
+
+pub use substrate_test_client::*;
+pub use frontier_template_runtime as runtime;
+use sp_runtime::traits::HashFor;
+
+sc_executor::native_executor_instance! {
+	pub LocalExecutor,
+	runtime::api::dispatch,
+	runtime::native_version,
+}
+
+pub type Backend = substrate_test_client::Backend<runtime::opaque::Block>;
+
+pub type Executor = client::LocalCallExecutor<
+	Backend,
+	NativeExecutor<LocalExecutor>,
+>;
+
+pub type LightBackend = substrate_test_client::LightBackend<runtime::opaque::Block>;
+
+pub type LightExecutor = sc_light::GenesisCallExecutor<
+	LightBackend,
+	client::LocalCallExecutor<
+		sc_light::Backend<
+			sc_client_db::light::LightStorage<runtime::opaque::Block>,
+			HashFor<runtime::opaque::Block>
+		>,
+		NativeExecutor<LocalExecutor>
+	>
+>;
+
+/// Parameters of test-client builder with test-runtime.
+#[derive(Default)]
+pub struct GenesisParameters;
+
+impl substrate_test_client::GenesisInit for GenesisParameters {
+	fn genesis_storage(&self) -> Storage {
+		Storage::default()
+	}
+}
+
+/// A `TestClient` with `test-runtime` builder.
+pub type TestClientBuilder<E, B> = substrate_test_client::TestClientBuilder<
+	runtime::opaque::Block,
+	E,
+	B,
+	GenesisParameters,
+>;
+
+/// Test client type with `LocalExecutor` and generic Backend.
+pub type Client<B> = client::Client<
+	B,
+	client::LocalCallExecutor<B, sc_executor::NativeExecutor<LocalExecutor>>,
+	runtime::opaque::Block,
+	runtime::RuntimeApi,
+>;
+
+/// A test client with default backend.
+pub type TestClient = Client<Backend>;
+
+/// A `TestClientBuilder` with default backend and executor.
+pub trait DefaultTestClientBuilderExt: Sized {
+	/// Create new `TestClientBuilder`
+	fn new() -> Self;
+}
+
+impl DefaultTestClientBuilderExt for TestClientBuilder<Executor, Backend> {
+	fn new() -> Self {
+		Self::with_default_backend()
+	}
+}
+
+/// A `test-runtime` extensions to `TestClientBuilder`.
+pub trait TestClientBuilderExt<B>: Sized {
+	/// Build the test client.
+	fn build(self) -> Client<B> {
+		self.build_with_longest_chain().0
+	}
+
+	/// Build the test client and longest chain selector.
+	fn build_with_longest_chain(self) -> (Client<B>, sc_consensus::LongestChain<B, runtime::opaque::Block>);
+
+	/// Build the test client and the backend.
+	fn build_with_backend(self) -> (Client<B>, Arc<B>);
+}
+
+impl<B> TestClientBuilderExt<B> for TestClientBuilder<
+	client::LocalCallExecutor<B, sc_executor::NativeExecutor<LocalExecutor>>,
+	B
+> where
+	B: sc_client_api::backend::Backend<runtime::opaque::Block> + 'static,
+	// Rust bug: https://github.com/rust-lang/rust/issues/24159
+	<B as sc_client_api::backend::Backend<runtime::opaque::Block>>::State:
+		sp_api::StateBackend<HashFor<runtime::opaque::Block>>,
+{
+	fn build_with_longest_chain(self) -> (Client<B>, sc_consensus::LongestChain<B, runtime::opaque::Block>) {
+		self.build_with_native_executor(None)
+	}
+
+	fn build_with_backend(self) -> (Client<B>, Arc<B>) {
+		let backend = self.backend();
+		(self.build_with_native_executor(None).0, backend)
+	}
+}
+
+/// Creates new client instance used for tests.
+pub fn new() -> Client<Backend> {
+	TestClientBuilder::new().build()
+}