From 0d6a0f66b42fcb5072f240978f1714d104ac2d9f Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Wed, 30 Oct 2019 17:10:14 +0100
Subject: [PATCH 01/14] Extract CLI to separate module in node/cli

---
 core/service/Cargo.toml |   2 +-
 node/cli/Cargo.toml     |  20 ++--
 node/cli/bin/main.rs    |   6 +-
 node/cli/build.rs       |   2 +-
 node/cli/src/cli.rs     | 212 ++++++++++++++++++++++++++++++++++++++++
 node/cli/src/lib.rs     | 197 +------------------------------------
 6 files changed, 234 insertions(+), 205 deletions(-)
 create mode 100644 node/cli/src/cli.rs

diff --git a/core/service/Cargo.toml b/core/service/Cargo.toml
index 0d6f27936244f..76d68eb45f94f 100644
--- a/core/service/Cargo.toml
+++ b/core/service/Cargo.toml
@@ -29,7 +29,7 @@ consensus_common = { package = "substrate-consensus-common", path = "../../core/
 network = { package = "substrate-network", path = "../../core/network" }
 chain-spec = { package = "substrate-chain-spec", path = "../chain-spec" }
 client = { package = "substrate-client", path = "../../core/client" }
-client_db = { package = "substrate-client-db", path = "../../core/client/db", features = ["kvdb-rocksdb"] }
+client_db = { package = "substrate-client-db", path = "../../core/client/db" }
 codec = { package = "parity-scale-codec", version = "1.0.0" }
 substrate-executor = { path = "../../core/executor" }
 transaction_pool = { package = "substrate-transaction-pool", path = "../../core/transaction-pool" }
diff --git a/node/cli/Cargo.toml b/node/cli/Cargo.toml
index b85014eeef06a..11a9f098cad71 100644
--- a/node/cli/Cargo.toml
+++ b/node/cli/Cargo.toml
@@ -16,14 +16,15 @@ is-it-maintained-open-issues = { repository = "paritytech/substrate" }
 [[bin]]
 name = "substrate"
 path = "bin/main.rs"
+required-features = ["cli"]
 
 [dependencies]
 log = "0.4.8"
-tokio = "0.1.22"
+tokio = { version = "0.1.22", optional = true }
 futures = "0.1.29"
-exit-future = "0.1.4"
+exit-future = { version = "0.1.4", optional = true }
 jsonrpc-core = "13.2.0"
-cli = { package = "substrate-cli", path = "../../core/cli" }
+substrate-cli = { path = "../../core/cli", optional = true }
 codec = { package = "parity-scale-codec", version = "1.0.0" }
 sr-io = { path = "../../core/sr-io" }
 client = { package = "substrate-client", path = "../../core/client" }
@@ -47,7 +48,7 @@ sr-primitives = { path = "../../core/sr-primitives" }
 node-executor = { path = "../executor" }
 substrate-telemetry = { package = "substrate-telemetry", path = "../../core/telemetry" }
 structopt = "0.3.3"
-transaction-factory = { path = "../../test-utils/transaction-factory" }
+transaction-factory = { path = "../../test-utils/transaction-factory", optional = true }
 keyring = { package = "substrate-keyring", path = "../../core/keyring" }
 indices = { package = "srml-indices", path = "../../srml/indices" }
 timestamp = { package = "srml-timestamp", path = "../../srml/timestamp", default-features = false }
@@ -60,9 +61,9 @@ transaction-payment = { package = "srml-transaction-payment", path = "../../srml
 support = { package = "srml-support", path = "../../srml/support", default-features = false }
 im_online = { package = "srml-im-online", path = "../../srml/im-online", default-features = false }
 serde = { version = "1.0.101", features = [ "derive" ] }
-client_db = { package = "substrate-client-db", path = "../../core/client/db", features = ["kvdb-rocksdb"] }
+client_db = { package = "substrate-client-db", path = "../../core/client/db", default-features = false }
 offchain = { package = "substrate-offchain", path = "../../core/offchain" }
-ctrlc = { version = "3.1.3", features = ["termination"] }
+ctrlc = { version = "3.1.3", features = ["termination"], optional = true }
 
 [dev-dependencies]
 keystore = { package = "substrate-keystore", path = "../../core/keystore" }
@@ -73,6 +74,11 @@ futures03 = { package = "futures-preview", version = "0.3.0-alpha.19" }
 tempfile = "3.1.0"
 
 [build-dependencies]
-cli = { package = "substrate-cli", path = "../../core/cli" }
+substrate-cli = { package = "substrate-cli", path = "../../core/cli" }
 structopt = "0.3.3"
 vergen = "3.0.4"
+
+[features]
+default = ["cli"]
+# TODO: docs
+cli = ["substrate-cli", "transaction-factory", "tokio", "exit-future", "ctrlc", "client_db/kvdb-rocksdb"]
diff --git a/node/cli/bin/main.rs b/node/cli/bin/main.rs
index 4b07d8c8a4805..e4415a2a89e66 100644
--- a/node/cli/bin/main.rs
+++ b/node/cli/bin/main.rs
@@ -18,15 +18,15 @@
 
 #![warn(missing_docs)]
 
-use cli::VersionInfo;
 use futures::sync::oneshot;
 use futures::{future, Future};
+use substrate_cli::VersionInfo;
 
 use std::cell::RefCell;
 
 // handles ctrl-c
 struct Exit;
-impl cli::IntoExit for Exit {
+impl substrate_cli::IntoExit for Exit {
 	type Exit = future::MapErr<oneshot::Receiver<()>, fn(oneshot::Canceled) -> ()>;
 	fn into_exit(self) -> Self::Exit {
 		// can't use signal directly here because CtrlC takes only `Fn`.
@@ -43,7 +43,7 @@ impl cli::IntoExit for Exit {
 	}
 }
 
-fn main() -> Result<(), cli::error::Error> {
+fn main() -> Result<(), substrate_cli::error::Error> {
 	let version = VersionInfo {
 		name: "Substrate Node",
 		commit: env!("VERGEN_SHA_SHORT"),
diff --git a/node/cli/build.rs b/node/cli/build.rs
index 48b57c4600e80..8ef644eed5d94 100644
--- a/node/cli/build.rs
+++ b/node/cli/build.rs
@@ -14,9 +14,9 @@
 // You should have received a copy of the GNU General Public License
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
-use cli::{NoCustom, CoreParams};
 use std::{fs, env, path::Path};
 use structopt::{StructOpt, clap::Shell};
+use substrate_cli::{NoCustom, CoreParams};
 use vergen::{ConstantsFlags, generate_cargo_keys};
 
 fn main() {
diff --git a/node/cli/src/cli.rs b/node/cli/src/cli.rs
new file mode 100644
index 0000000000000..3f8c9c5657f7a
--- /dev/null
+++ b/node/cli/src/cli.rs
@@ -0,0 +1,212 @@
+// Copyright 2018-2019 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Substrate is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+#![cfg(feature = "cli")]
+
+pub use substrate_cli::error;
+use tokio::prelude::Future;
+use tokio::runtime::{Builder as RuntimeBuilder, Runtime};
+pub use substrate_cli::{VersionInfo, IntoExit, NoCustom, SharedParams, ExecutionStrategyParam};
+use substrate_service::{AbstractService, Roles as ServiceRoles, Configuration};
+use log::info;
+use structopt::{StructOpt, clap::App};
+use substrate_cli::{display_role, parse_and_prepare, AugmentClap, GetLogFilter, ParseAndPrepare};
+use crate::{service, ChainSpec, load_spec};
+use crate::factory_impl::FactoryState;
+use transaction_factory::RuntimeAdapter;
+use client::ExecutionStrategies;
+
+/// Custom subcommands.
+#[derive(Clone, Debug, StructOpt)]
+pub enum CustomSubcommands {
+	/// The custom factory subcommmand for manufacturing transactions.
+	#[structopt(
+		name = "factory",
+		about = "Manufactures num transactions from Alice to random accounts. \
+		Only supported for development or local testnet."
+	)]
+	Factory(FactoryCmd),
+}
+
+impl GetLogFilter for CustomSubcommands {
+	fn get_log_filter(&self) -> Option<String> {
+		None
+	}
+}
+
+/// The `factory` command used to generate transactions.
+/// Please note: this command currently only works on an empty database!
+#[derive(Debug, StructOpt, Clone)]
+pub struct FactoryCmd {
+	/// How often to repeat. This option only has an effect in mode `MasterToNToM`.
+	#[structopt(long="rounds", default_value = "1")]
+	pub rounds: u64,
+
+	/// MasterToN: Manufacture `num` transactions from the master account
+	///            to `num` randomly created accounts, one each.
+	///
+	/// MasterTo1: Manufacture `num` transactions from the master account
+	///            to exactly one other randomly created account.
+	///
+	/// MasterToNToM: Manufacture `num` transactions from the master account
+	///               to `num` randomly created accounts.
+	///               From each of these randomly created accounts manufacture
+	///               a transaction to another randomly created account.
+	///               Repeat this `rounds` times. If `rounds` = 1 the behavior
+	///               is the same as `MasterToN`.{n}
+	///               A -> B, A -> C, A -> D, ... x `num`{n}
+	///               B -> E, C -> F, D -> G, ...{n}
+	///               ... x `rounds`
+	///
+	/// These three modes control manufacturing.
+	#[structopt(long="mode", default_value = "MasterToN")]
+	pub mode: transaction_factory::Mode,
+
+	/// Number of transactions to generate. In mode `MasterNToNToM` this is
+	/// the number of transactions per round.
+	#[structopt(long="num", default_value = "8")]
+	pub num: u64,
+
+	#[allow(missing_docs)]
+	#[structopt(flatten)]
+	pub shared_params: SharedParams,
+
+	/// The means of execution used when calling into the runtime while importing blocks.
+	#[structopt(
+		long = "execution",
+		value_name = "STRATEGY",
+		possible_values = &ExecutionStrategyParam::variants(),
+		case_insensitive = true,
+		default_value = "NativeElseWasm"
+	)]
+	pub execution: ExecutionStrategyParam,
+}
+
+impl AugmentClap for FactoryCmd {
+	fn augment_clap<'a, 'b>(app: App<'a, 'b>) -> App<'a, 'b> {
+		FactoryCmd::augment_clap(app)
+	}
+}
+
+/// Parse command line arguments into service configuration.
+pub fn run<I, T, E>(args: I, exit: E, version: substrate_cli::VersionInfo) -> error::Result<()> where
+	I: IntoIterator<Item = T>,
+	T: Into<std::ffi::OsString> + Clone,
+	E: IntoExit,
+{
+	type Config<A, B> = Configuration<(), A, B>;
+
+	match parse_and_prepare::<CustomSubcommands, NoCustom, _>(&version, "substrate-node", args) {
+		ParseAndPrepare::Run(cmd) => cmd.run(load_spec, exit,
+		|exit, _cli_args, _custom_args, config: Config<_, _>| {
+			info!("{}", version.name);
+			info!("  version {}", config.full_version());
+			info!("  by Parity Technologies, 2017-2019");
+			info!("Chain specification: {}", config.chain_spec.name());
+			info!("Node name: {}", config.name);
+			info!("Roles: {}", display_role(&config));
+			let runtime = RuntimeBuilder::new().name_prefix("main-tokio-").build()
+				.map_err(|e| format!("{:?}", e))?;
+			match config.roles {
+				ServiceRoles::LIGHT => run_until_exit(
+					runtime,
+					service::new_light(config)?,
+					exit
+				),
+				_ => run_until_exit(
+					runtime,
+					service::new_full(config)?,
+					exit
+				),
+			}
+		}),
+		ParseAndPrepare::BuildSpec(cmd) => cmd.run(load_spec),
+		ParseAndPrepare::ExportBlocks(cmd) => cmd.run_with_builder(|config: Config<_, _>|
+			Ok(new_full_start!(config).0), load_spec, exit),
+		ParseAndPrepare::ImportBlocks(cmd) => cmd.run_with_builder(|config: Config<_, _>|
+			Ok(new_full_start!(config).0), load_spec, exit),
+		ParseAndPrepare::PurgeChain(cmd) => cmd.run(load_spec),
+		ParseAndPrepare::RevertChain(cmd) => cmd.run_with_builder(|config: Config<_, _>|
+			Ok(new_full_start!(config).0), load_spec),
+		ParseAndPrepare::CustomCommand(CustomSubcommands::Factory(cli_args)) => {
+			let mut config: Config<_, _> = substrate_cli::create_config_with_db_path(
+				load_spec,
+				&cli_args.shared_params,
+				&version,
+			)?;
+			config.execution_strategies = ExecutionStrategies {
+				importing: cli_args.execution.into(),
+				block_construction: cli_args.execution.into(),
+				other: cli_args.execution.into(),
+				..Default::default()
+			};
+
+			match ChainSpec::from(config.chain_spec.id()) {
+				Some(ref c) if c == &ChainSpec::Development || c == &ChainSpec::LocalTestnet => {},
+				_ => panic!("Factory is only supported for development and local testnet."),
+			}
+
+			let factory_state = FactoryState::new(
+				cli_args.mode.clone(),
+				cli_args.num,
+				cli_args.rounds,
+			);
+
+			let service_builder = new_full_start!(config).0;
+			transaction_factory::factory::<FactoryState<_>, _, _, _, _, _>(
+				factory_state,
+				service_builder.client(),
+				service_builder.select_chain()
+					.expect("The select_chain is always initialized by new_full_start!; QED")
+			).map_err(|e| format!("Error in transaction factory: {}", e))?;
+
+			Ok(())
+		}
+	}
+}
+
+fn run_until_exit<T, E>(
+	mut runtime: Runtime,
+	service: T,
+	e: E,
+) -> error::Result<()>
+where
+	T: AbstractService,
+	E: IntoExit,
+{
+	let (exit_send, exit) = exit_future::signal();
+
+	let informant = substrate_cli::informant::build(&service);
+	runtime.executor().spawn(exit.until(informant).map(|_| ()));
+
+	// we eagerly drop the service so that the internal exit future is fired,
+	// but we need to keep holding a reference to the global telemetry guard
+	let _telemetry = service.telemetry();
+
+	let service_res = {
+		let exit = e.into_exit().map_err(|_| error::Error::Other("Exit future failed.".into()));
+		let service = service.map_err(|err| error::Error::Service(err));
+		let select = service.select(exit).map(|_| ()).map_err(|(err, _)| err);
+		runtime.block_on(select)
+	};
+
+	exit_send.fire();
+
+	// TODO [andre]: timeout this future #1318
+	let _ = runtime.shutdown_on_idle().wait();
+
+	service_res
+}
diff --git a/node/cli/src/lib.rs b/node/cli/src/lib.rs
index 5125ba216a2cc..ad79485209689 100644
--- a/node/cli/src/lib.rs
+++ b/node/cli/src/lib.rs
@@ -19,22 +19,15 @@
 #![warn(missing_docs)]
 #![warn(unused_extern_crates)]
 
-pub use cli::error;
 pub mod chain_spec;
+
 #[macro_use]
 mod service;
+mod cli;
 mod factory_impl;
 
-use tokio::prelude::Future;
-use tokio::runtime::{Builder as RuntimeBuilder, Runtime};
-pub use cli::{VersionInfo, IntoExit, NoCustom, SharedParams, ExecutionStrategyParam};
-use substrate_service::{AbstractService, Roles as ServiceRoles, Configuration};
-use log::info;
-use structopt::{StructOpt, clap::App};
-use cli::{display_role, parse_and_prepare, AugmentClap, GetLogFilter, ParseAndPrepare};
-use crate::factory_impl::FactoryState;
-use transaction_factory::RuntimeAdapter;
-use client::ExecutionStrategies;
+#[cfg(feature = "cli")]
+pub use cli::*;
 
 /// The chain specification option.
 #[derive(Clone, Debug, PartialEq)]
@@ -49,78 +42,6 @@ pub enum ChainSpec {
 	StagingTestnet,
 }
 
-/// Custom subcommands.
-#[derive(Clone, Debug, StructOpt)]
-pub enum CustomSubcommands {
-	/// The custom factory subcommmand for manufacturing transactions.
-	#[structopt(
-		name = "factory",
-		about = "Manufactures num transactions from Alice to random accounts. \
-		Only supported for development or local testnet."
-	)]
-	Factory(FactoryCmd),
-}
-
-impl GetLogFilter for CustomSubcommands {
-	fn get_log_filter(&self) -> Option<String> {
-		None
-	}
-}
-
-/// The `factory` command used to generate transactions.
-/// Please note: this command currently only works on an empty database!
-#[derive(Debug, StructOpt, Clone)]
-pub struct FactoryCmd {
-	/// How often to repeat. This option only has an effect in mode `MasterToNToM`.
-	#[structopt(long="rounds", default_value = "1")]
-	pub rounds: u64,
-
-	/// MasterToN: Manufacture `num` transactions from the master account
-	///            to `num` randomly created accounts, one each.
-	///
-	/// MasterTo1: Manufacture `num` transactions from the master account
-	///            to exactly one other randomly created account.
-	///
-	/// MasterToNToM: Manufacture `num` transactions from the master account
-	///               to `num` randomly created accounts.
-	///               From each of these randomly created accounts manufacture
-	///               a transaction to another randomly created account.
-	///               Repeat this `rounds` times. If `rounds` = 1 the behavior
-	///               is the same as `MasterToN`.{n}
-	///               A -> B, A -> C, A -> D, ... x `num`{n}
-	///               B -> E, C -> F, D -> G, ...{n}
-	///               ... x `rounds`
-	///
-	/// These three modes control manufacturing.
-	#[structopt(long="mode", default_value = "MasterToN")]
-	pub mode: transaction_factory::Mode,
-
-	/// Number of transactions to generate. In mode `MasterNToNToM` this is
-	/// the number of transactions per round.
-	#[structopt(long="num", default_value = "8")]
-	pub num: u64,
-
-	#[allow(missing_docs)]
-	#[structopt(flatten)]
-	pub shared_params: SharedParams,
-
-	/// The means of execution used when calling into the runtime while importing blocks.
-	#[structopt(
-		long = "execution",
-		value_name = "STRATEGY",
-		possible_values = &ExecutionStrategyParam::variants(),
-		case_insensitive = true,
-		default_value = "NativeElseWasm"
-	)]
-	pub execution: ExecutionStrategyParam,
-}
-
-impl AugmentClap for FactoryCmd {
-	fn augment_clap<'a, 'b>(app: App<'a, 'b>) -> App<'a, 'b> {
-		FactoryCmd::augment_clap(app)
-	}
-}
-
 /// Get a chain config from a spec setting.
 impl ChainSpec {
 	pub(crate) fn load(self) -> Result<chain_spec::ChainSpec, String> {
@@ -149,113 +70,3 @@ fn load_spec(id: &str) -> Result<Option<chain_spec::ChainSpec>, String> {
 		None => None,
 	})
 }
-
-/// Parse command line arguments into service configuration.
-pub fn run<I, T, E>(args: I, exit: E, version: cli::VersionInfo) -> error::Result<()> where
-	I: IntoIterator<Item = T>,
-	T: Into<std::ffi::OsString> + Clone,
-	E: IntoExit,
-{
-	type Config<A, B> = Configuration<(), A, B>;
-
-	match parse_and_prepare::<CustomSubcommands, NoCustom, _>(&version, "substrate-node", args) {
-		ParseAndPrepare::Run(cmd) => cmd.run(load_spec, exit,
-		|exit, _cli_args, _custom_args, config: Config<_, _>| {
-			info!("{}", version.name);
-			info!("  version {}", config.full_version());
-			info!("  by Parity Technologies, 2017-2019");
-			info!("Chain specification: {}", config.chain_spec.name());
-			info!("Node name: {}", config.name);
-			info!("Roles: {}", display_role(&config));
-			let runtime = RuntimeBuilder::new().name_prefix("main-tokio-").build()
-				.map_err(|e| format!("{:?}", e))?;
-			match config.roles {
-				ServiceRoles::LIGHT => run_until_exit(
-					runtime,
-					service::new_light(config)?,
-					exit
-				),
-				_ => run_until_exit(
-					runtime,
-					service::new_full(config)?,
-					exit
-				),
-			}
-		}),
-		ParseAndPrepare::BuildSpec(cmd) => cmd.run(load_spec),
-		ParseAndPrepare::ExportBlocks(cmd) => cmd.run_with_builder(|config: Config<_, _>|
-			Ok(new_full_start!(config).0), load_spec, exit),
-		ParseAndPrepare::ImportBlocks(cmd) => cmd.run_with_builder(|config: Config<_, _>|
-			Ok(new_full_start!(config).0), load_spec, exit),
-		ParseAndPrepare::PurgeChain(cmd) => cmd.run(load_spec),
-		ParseAndPrepare::RevertChain(cmd) => cmd.run_with_builder(|config: Config<_, _>|
-			Ok(new_full_start!(config).0), load_spec),
-		ParseAndPrepare::CustomCommand(CustomSubcommands::Factory(cli_args)) => {
-			let mut config: Config<_, _> = cli::create_config_with_db_path(
-				load_spec,
-				&cli_args.shared_params,
-				&version,
-			)?;
-			config.execution_strategies = ExecutionStrategies {
-				importing: cli_args.execution.into(),
-				block_construction: cli_args.execution.into(),
-				other: cli_args.execution.into(),
-				..Default::default()
-			};
-
-			match ChainSpec::from(config.chain_spec.id()) {
-				Some(ref c) if c == &ChainSpec::Development || c == &ChainSpec::LocalTestnet => {},
-				_ => panic!("Factory is only supported for development and local testnet."),
-			}
-
-			let factory_state = FactoryState::new(
-				cli_args.mode.clone(),
-				cli_args.num,
-				cli_args.rounds,
-			);
-
-			let service_builder = new_full_start!(config).0;
-			transaction_factory::factory::<FactoryState<_>, _, _, _, _, _>(
-				factory_state,
-				service_builder.client(),
-				service_builder.select_chain()
-					.expect("The select_chain is always initialized by new_full_start!; QED")
-			).map_err(|e| format!("Error in transaction factory: {}", e))?;
-
-			Ok(())
-		}
-	}
-}
-
-fn run_until_exit<T, E>(
-	mut runtime: Runtime,
-	service: T,
-	e: E,
-) -> error::Result<()>
-where
-	T: AbstractService,
-	E: IntoExit,
-{
-	let (exit_send, exit) = exit_future::signal();
-
-	let informant = cli::informant::build(&service);
-	runtime.executor().spawn(exit.until(informant).map(|_| ()));
-
-	// we eagerly drop the service so that the internal exit future is fired,
-	// but we need to keep holding a reference to the global telemetry guard
-	let _telemetry = service.telemetry();
-
-	let service_res = {
-		let exit = e.into_exit().map_err(|_| error::Error::Other("Exit future failed.".into()));
-		let service = service.map_err(|err| error::Error::Service(err));
-		let select = service.select(exit).map(|_| ()).map_err(|(err, _)| err);
-		runtime.block_on(select)
-	};
-
-	exit_send.fire();
-
-	// TODO [andre]: timeout this future #1318
-	let _ = runtime.shutdown_on_idle().wait();
-
-	service_res
-}

From 222a6deadc1501d2235243711659684510fa7770 Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Wed, 30 Oct 2019 17:32:24 +0100
Subject: [PATCH 02/14] Make node/cli compile for WASM

---
 core/service/src/lib.rs      | 4 ++--
 node/cli/src/factory_impl.rs | 2 ++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/core/service/src/lib.rs b/core/service/src/lib.rs
index 3057b8ce4dcd4..bc1a15542de81 100644
--- a/core/service/src/lib.rs
+++ b/core/service/src/lib.rs
@@ -541,10 +541,10 @@ fn start_rpc_servers<C, G, E, H: FnMut() -> rpc_servers::RpcHandler<rpc::Metadat
 
 /// Starts RPC servers that run in their own thread, and returns an opaque object that keeps them alive.
 #[cfg(target_os = "unknown")]
-fn start_rpc_servers<C, G, E, H: FnMut() -> components::RpcHandler>(
+fn start_rpc_servers<C, G, E, H: FnMut() -> rpc_servers::RpcHandler<rpc::Metadata>>(
 	_: &Configuration<C, G, E>,
 	_: H
-) -> Result<Box<std::any::Any + Send + Sync>, error::Error> {
+) -> Result<Box<dyn std::any::Any + Send + Sync>, error::Error> {
 	Ok(Box::new(()))
 }
 
diff --git a/node/cli/src/factory_impl.rs b/node/cli/src/factory_impl.rs
index 48fb7b237f1e6..6578350a5a6dd 100644
--- a/node/cli/src/factory_impl.rs
+++ b/node/cli/src/factory_impl.rs
@@ -18,6 +18,8 @@
 //! using the cli to manufacture transactions and distribute them
 //! to accounts.
 
+#![cfg(feature = "cli")]
+
 use rand::{Rng, SeedableRng};
 use rand::rngs::StdRng;
 

From 2a282e96998e77f7a4a30de4870421182eef6227 Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Wed, 30 Oct 2019 18:10:21 +0100
Subject: [PATCH 03/14] More work on node/cli browser

---
 Cargo.lock                        |  28 ++++++
 core/service/src/lib.rs           |   1 +
 node/cli/Cargo.toml               |  14 +++
 node/cli/browser-demo/.gitignore  |   1 +
 node/cli/browser-demo/README.md   |  10 ++
 node/cli/browser-demo/build.sh    |   4 +
 node/cli/browser-demo/favicon.png | Bin 0 -> 10338 bytes
 node/cli/browser-demo/index.html  |  42 +++++++++
 node/cli/browser-demo/ws.js       | 148 +++++++++++++++++++++++++++++
 node/cli/src/browser.rs           | 151 ++++++++++++++++++++++++++++++
 node/cli/src/lib.rs               |   3 +
 11 files changed, 402 insertions(+)
 create mode 100644 node/cli/browser-demo/.gitignore
 create mode 100644 node/cli/browser-demo/README.md
 create mode 100755 node/cli/browser-demo/build.sh
 create mode 100644 node/cli/browser-demo/favicon.png
 create mode 100644 node/cli/browser-demo/index.html
 create mode 100644 node/cli/browser-demo/ws.js
 create mode 100644 node/cli/src/browser.rs

diff --git a/Cargo.lock b/Cargo.lock
index 75a1b797b07c3..4f3db5032fe53 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -468,6 +468,24 @@ dependencies = [
  "cc 1.0.45 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "console_error_panic_hook"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "console_log"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "web-sys 0.3.28 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "const-random"
 version = "0.1.6"
@@ -1153,6 +1171,7 @@ dependencies = [
  "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
  "wasi 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2377,12 +2396,17 @@ dependencies = [
 name = "node-cli"
 version = "2.0.0"
 dependencies = [
+ "clear_on_drop 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "console_error_panic_hook 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "console_log 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "ctrlc 3.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "exit-future 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.29 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex-literal 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "js-sys 0.3.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "jsonrpc-core 13.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libp2p 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "node-executor 2.0.0",
  "node-primitives 2.0.0",
@@ -2428,6 +2452,8 @@ dependencies = [
  "tokio 0.1.22 (registry+https://github.com/rust-lang/crates.io-index)",
  "transaction-factory 0.0.1",
  "vergen 3.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen-futures 0.3.27 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -6909,6 +6935,8 @@ dependencies = [
 "checksum clear_on_drop 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "97276801e127ffb46b66ce23f35cc96bd454fa311294bced4bbace7baa8b1d17"
 "checksum cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ddfc5b9aa5d4507acaf872de71051dfd0e309860e88966e1051e462a077aac4f"
 "checksum cmake 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)" = "81fb25b677f8bf1eb325017cb6bb8452f87969db0fedb4f757b297bee78a7c62"
+"checksum console_error_panic_hook 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "b8d976903543e0c48546a91908f21588a680a8c8f984df9a5d69feccb2b2a211"
+"checksum console_log 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "1e7871d2947441b0fdd8e2bd1ce2a2f75304f896582c0d572162d48290683c48"
 "checksum const-random 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "7b641a8c9867e341f3295564203b1c250eb8ce6cb6126e007941f78c4d2ed7fe"
 "checksum const-random-macro 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "c750ec12b83377637110d5a57f5ae08e895b06c4b16e2bdbf1a94ef717428c59"
 "checksum constant_time_eq 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "995a44c877f9212528ccc74b21a232f66ad69001e40ede5bcee2ac9ef2657120"
diff --git a/core/service/src/lib.rs b/core/service/src/lib.rs
index bc1a15542de81..c46732d511b3e 100644
--- a/core/service/src/lib.rs
+++ b/core/service/src/lib.rs
@@ -550,6 +550,7 @@ fn start_rpc_servers<C, G, E, H: FnMut() -> rpc_servers::RpcHandler<rpc::Metadat
 
 /// An RPC session. Used to perform in-memory RPC queries (ie. RPC queries that don't go through
 /// the HTTP or WebSockets server).
+#[derive(Clone)]
 pub struct RpcSession {
 	metadata: rpc::Metadata,
 }
diff --git a/node/cli/Cargo.toml b/node/cli/Cargo.toml
index 11a9f098cad71..171583c100152 100644
--- a/node/cli/Cargo.toml
+++ b/node/cli/Cargo.toml
@@ -18,6 +18,9 @@ name = "substrate"
 path = "bin/main.rs"
 required-features = ["cli"]
 
+[lib]
+crate-type = ["cdylib", "rlib"]
+
 [dependencies]
 log = "0.4.8"
 tokio = { version = "0.1.22", optional = true }
@@ -65,6 +68,15 @@ client_db = { package = "substrate-client-db", path = "../../core/client/db", de
 offchain = { package = "substrate-offchain", path = "../../core/offchain" }
 ctrlc = { version = "3.1.3", features = ["termination"], optional = true }
 
+# WASM-specific dependencies
+libp2p = { version = "0.12.0", default-features = false, optional = true }
+clear_on_drop = { version = "0.2.3", features = ["no_cc"], optional = true }
+console_error_panic_hook = { version = "0.1.1", optional = true }
+console_log = { version = "0.1.2", optional = true }
+js-sys = { version = "0.3.22", optional = true }
+wasm-bindgen = { version = "0.2.45", optional = true }
+wasm-bindgen-futures = { version = "0.3.22", optional = true }
+
 [dev-dependencies]
 keystore = { package = "substrate-keystore", path = "../../core/keystore" }
 babe = { package = "substrate-consensus-babe", path = "../../core/consensus/babe", features = ["test-helpers"] }
@@ -81,4 +93,6 @@ vergen = "3.0.4"
 [features]
 default = ["cli"]
 # TODO: docs
+browser = ["clear_on_drop", "console_error_panic_hook", "console_log", "js-sys", "libp2p", "wasm-bindgen", "wasm-bindgen-futures", "rand/wasm-bindgen"]
+# TODO: docs
 cli = ["substrate-cli", "transaction-factory", "tokio", "exit-future", "ctrlc", "client_db/kvdb-rocksdb"]
diff --git a/node/cli/browser-demo/.gitignore b/node/cli/browser-demo/.gitignore
new file mode 100644
index 0000000000000..0c6117d9fb83b
--- /dev/null
+++ b/node/cli/browser-demo/.gitignore
@@ -0,0 +1 @@
+pkg
\ No newline at end of file
diff --git a/node/cli/browser-demo/README.md b/node/cli/browser-demo/README.md
new file mode 100644
index 0000000000000..cc23023848f02
--- /dev/null
+++ b/node/cli/browser-demo/README.md
@@ -0,0 +1,10 @@
+# How to run this demo
+
+```sh
+cargo install wasm-pack		# If necessary
+
+# From the `node-browser` directory (parent from this README)
+wasm-pack build --target web --out-dir ./demo/pkg --no-typescript --release
+
+xdg-open index.html
+```
diff --git a/node/cli/browser-demo/build.sh b/node/cli/browser-demo/build.sh
new file mode 100755
index 0000000000000..5b34edeb4c08d
--- /dev/null
+++ b/node/cli/browser-demo/build.sh
@@ -0,0 +1,4 @@
+cd ..
+wasm-pack build --target web --out-dir ./browser-demo/pkg --no-typescript --release -- --no-default-features --features "browser"
+cd browser-demo
+python -m SimpleHTTPServer 8000
diff --git a/node/cli/browser-demo/favicon.png b/node/cli/browser-demo/favicon.png
new file mode 100644
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diff --git a/node/cli/browser-demo/index.html b/node/cli/browser-demo/index.html
new file mode 100644
index 0000000000000..123f146bf25e0
--- /dev/null
+++ b/node/cli/browser-demo/index.html
@@ -0,0 +1,42 @@
+<!DOCTYPE html>
+<html>
+  <head>
+	<meta http-equiv="Content-type" content="text/html; charset=utf-8"/>
+	<title>Substrate node</title>
+	<link rel="shortcut icon" href="/favicon.png" />
+	<script type="module">
+import { start_client, default as init } from './pkg/node_browser.js';
+import ws from './ws.js';
+
+function log(msg) {
+	document.getElementsByTagName('body')[0].innerHTML += msg + '\n';
+}
+
+async function start() {
+	log('Loading WASM');
+	await init('./pkg/node_browser_bg.wasm');
+	log('Successfully loaded WASM');
+
+	// Build our client.
+	log('Starting client');
+	let client = start_client(ws());
+	log('Client started');
+
+	client.rpcSubscribe('{"method":"chain_subscribeNewHead","params":[],"id":1,"jsonrpc":"2.0"}',
+		(r) => log("New chain head: " + r));
+
+	setInterval(() => {
+		client
+			.rpcSend('{"method":"system_networkState","params":[],"id":1,"jsonrpc":"2.0"}')
+			.then((r) => log("Network state: " + r));
+		client
+			.rpcSend('{"method":"system_networkState","params":[],"id":1,"jsonrpc":"2.0"}')
+			.then((r) => log("Network state: " + r));
+	}, 1000);
+}
+
+start();
+	</script>
+  </head>
+  <body style="white-space: pre"></body>
+</html>
diff --git a/node/cli/browser-demo/ws.js b/node/cli/browser-demo/ws.js
new file mode 100644
index 0000000000000..320f742a12ade
--- /dev/null
+++ b/node/cli/browser-demo/ws.js
@@ -0,0 +1,148 @@
+// Copyright 2018-2019 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Substrate is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+export default () => {
+	return {
+		dial: dial,
+		listen_on: (addr) => {
+			let err = new Error("Listening on WebSockets is not possible from within a browser");
+			err.name = "NotSupportedError";
+			throw err;
+		},
+	};
+}
+
+/// Turns a string multiaddress into a WebSockets string URL.
+// TODO: support dns addresses as well
+const multiaddr_to_ws = (addr) => {
+	let parsed = addr.match(/^\/(ip4|ip6|dns4|dns6)\/(.*?)\/tcp\/(.*?)\/(ws|wss|x-parity-ws\/(.*)|x-parity-wss\/(.*))$/);
+	let proto = 'wss';
+	if (parsed[4] == 'ws' || parsed[4] == 'x-parity-ws') {
+		proto = 'ws';
+	}
+	let url = decodeURIComponent(parsed[5] || parsed[6] || '');
+	if (parsed != null) {
+		if (parsed[1] == 'ip6') {
+			return proto + "://[" + parsed[2] + "]:" + parsed[3] + url;
+		} else {
+			return proto + "://" + parsed[2] + ":" + parsed[3] + url;
+		}
+	}
+
+	let err = new Error("Address not supported: " + addr);
+	err.name = "NotSupportedError";
+	throw err;
+}
+
+// Attempt to dial a multiaddress.
+const dial = (addr) => {
+	let ws = new WebSocket(multiaddr_to_ws(addr));
+	let reader = read_queue();
+
+	return new Promise((resolve, reject) => {
+		// TODO: handle ws.onerror properly after dialing has happened
+		ws.onerror = (ev) => reject(ev);
+		ws.onmessage = (ev) => reader.inject_blob(ev.data);
+		ws.onclose = () => reader.inject_eof();
+		ws.onopen = () => resolve({
+			read: (function*() { while(ws.readyState == 1) { yield reader.next(); } })(),
+			write: (data) => {
+				if (ws.readyState == 1) {
+					ws.send(data);
+					return promise_when_ws_finished(ws);
+				} else {
+					return Promise.reject("WebSocket is closed");
+				}
+			},
+			shutdown: () => {},
+			close: () => ws.close()
+		});
+	});
+}
+
+// Takes a WebSocket object and returns a Promise that resolves when bufferedAmount is 0.
+const promise_when_ws_finished = (ws) => {
+	if (ws.bufferedAmount == 0) {
+		return Promise.resolve();
+	}
+
+	return new Promise((resolve, reject) => {
+		setTimeout(function check() {
+			if (ws.bufferedAmount == 0) {
+				resolve();
+			} else {
+				setTimeout(check, 100);
+			}
+		}, 2);
+	})
+}
+
+// Creates a queue reading system.
+const read_queue = () => {
+	// State of the queue.
+	let state = {
+		// Array of promises resolving to `ArrayBuffer`s, that haven't been transmitted back with
+		// `next` yet.
+		queue: new Array(),
+		// If `resolve` isn't null, it is a "resolve" function of a promise that has already been
+		// returned by `next`. It should be called with some data.
+		resolve: null,
+	};
+
+	return {
+		// Inserts a new Blob in the queue.
+		inject_blob: (blob) => {
+			if (state.resolve != null) {
+				var resolve = state.resolve;
+				state.resolve = null;
+
+				var reader = new FileReader();
+				reader.addEventListener("loadend", () => resolve(reader.result));
+				reader.readAsArrayBuffer(blob);
+			} else {
+				state.queue.push(new Promise((resolve, reject) => {
+					var reader = new FileReader();
+					reader.addEventListener("loadend", () => resolve(reader.result));
+					reader.readAsArrayBuffer(blob);
+				}));
+			}
+		},
+
+		// Inserts an EOF message in the queue.
+		inject_eof: () => {
+			if (state.resolve != null) {
+				var resolve = state.resolve;
+				state.resolve = null;
+				resolve(null);
+			} else {
+				state.queue.push(Promise.resolve(null));
+			}
+		},
+
+		// Returns a Promise that yields the next entry as an ArrayBuffer.
+		next: () => {
+			if (state.queue.length != 0) {
+				return state.queue.shift(0);
+			} else {
+				if (state.resolve !== null)
+					throw "Internal error: already have a pending promise";
+				return new Promise((resolve, reject) => {
+					state.resolve = resolve;
+				});
+			}
+		}
+	};
+};
diff --git a/node/cli/src/browser.rs b/node/cli/src/browser.rs
new file mode 100644
index 0000000000000..31db0524b96e1
--- /dev/null
+++ b/node/cli/src/browser.rs
@@ -0,0 +1,151 @@
+// Copyright 2018-2019 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Substrate is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+#![cfg(feature = "browser")]
+
+use crate::ChainSpec;
+use futures::{prelude::*, sync::oneshot, sync::mpsc};
+use libp2p::wasm_ext;
+use log::{debug, info};
+use std::sync::Arc;
+use substrate_service::{AbstractService, RpcSession, Roles as ServiceRoles, Configuration};
+use wasm_bindgen::prelude::*;
+
+/// Starts the client.
+#[wasm_bindgen]
+pub fn start_client(wasm_ext: wasm_ext::ffi::Transport) -> Result<Client, JsValue> {
+	start_inner(wasm_ext)
+		.map_err(|err| JsValue::from_str(err.description()))
+}
+
+fn start_inner(wasm_ext: wasm_ext::ffi::Transport) -> Result<Client, Box<dyn std::error::Error>> {
+	console_error_panic_hook::set_once();
+	console_log::init_with_level(log::Level::Info);
+
+	let wasm_ext = wasm_ext::ExtTransport::new(wasm_ext);
+
+	let chain_spec = ChainSpec::FlamingFir.load().map_err(|e| format!("{:?}", e))?;
+	let mut config = Configuration::<(), _, _>::default_with_spec(chain_spec);
+	config.network.transport = network::config::TransportConfig::Normal {
+		wasm_external_transport: Some(wasm_ext.clone()),
+		enable_mdns: false,
+	};
+	config.telemetry_external_transport = Some(wasm_ext);
+	config.roles = ServiceRoles::FULL;
+	config.name = "Browser node".to_string();
+    // TODO: config.database
+
+	//info!("{}", version.name);
+	info!("  version {}", config.full_version());
+	info!("  by Parity Technologies, 2017-2019");
+	info!("Chain specification: {}", config.chain_spec.name());
+	info!("Node name: {}", config.name);
+	info!("Roles: {:?}", config.roles);
+
+	let mut service = new_full!(config)
+		.map_err(|e: String| format!("{:?}", e))?.0;
+
+	/*let informant = substrate_cli::informant::build(&service);
+	wasm_bindgen_futures::spawn_local(informant);*/
+
+	let (rpc_send_tx, mut rpc_send_rx) = mpsc::unbounded::<RpcMessage>();
+	wasm_bindgen_futures::spawn_local(futures::future::poll_fn(move || {
+		loop {
+			match rpc_send_rx.poll() {
+				Ok(Async::Ready(Some(message))) => {
+					let fut = service.rpc_query(&message.session, &message.rpc_json);
+					let _ = message.send_back.send(Box::new(fut));
+				},
+				Ok(Async::NotReady) => break,
+				Err(_) | Ok(Async::Ready(None)) => return Ok(Async::Ready(())),
+			}
+		}
+
+		loop {
+			match service.poll().map_err(|_| ())? {
+				Async::Ready(()) => return Ok(Async::Ready(())),
+				Async::NotReady => break
+			}
+		}
+
+		Ok(Async::NotReady)
+	}));
+
+	Ok(Client {
+		rpc_send_tx,
+	})
+}
+
+/// A running client.
+#[wasm_bindgen]
+pub struct Client {
+	rpc_send_tx: mpsc::UnboundedSender<RpcMessage>,
+}
+
+struct RpcMessage {
+	rpc_json: String,
+	session: RpcSession,
+	send_back: oneshot::Sender<Box<dyn Future<Item = Option<String>, Error = ()>>>,
+}
+
+#[wasm_bindgen]
+impl Client {
+	/// Allows starting an RPC request. Returns a `Promise` containing the result of that request.
+	#[wasm_bindgen(js_name = "rpcSend")]
+	pub fn rpc_send(&mut self, rpc: &str) -> js_sys::Promise {
+		let rpc_session = RpcSession::new(mpsc::channel(1).0);
+		let (tx, rx) = oneshot::channel();
+		let _ = self.rpc_send_tx.unbounded_send(RpcMessage {
+			rpc_json: rpc.to_owned(),
+			session: rpc_session,
+			send_back: tx,
+		});
+		let fut = rx
+			.map_err(|_| ())
+			.and_then(|fut| fut)
+			.map(|s| JsValue::from_str(&s.unwrap_or(String::new())))
+			.map_err(|_| JsValue::NULL);
+		wasm_bindgen_futures::future_to_promise(fut)
+	}
+
+	/// Subscribes to an RPC pubsub endpoint.
+	#[wasm_bindgen(js_name = "rpcSubscribe")]
+	pub fn rpc_subscribe(&mut self, rpc: &str, callback: js_sys::Function) {
+		let (tx, rx) = mpsc::channel(4);
+		let rpc_session = RpcSession::new(tx);
+		let (fut_tx, fut_rx) = oneshot::channel();
+		let _ = self.rpc_send_tx.unbounded_send(RpcMessage {
+			rpc_json: rpc.to_owned(),
+			session: rpc_session.clone(),
+			send_back: fut_tx,
+		});
+		let fut_rx = fut_rx
+			.map_err(|_| ())
+			.and_then(|fut| fut);
+		wasm_bindgen_futures::spawn_local(fut_rx.then(|_| Ok(())));
+		wasm_bindgen_futures::spawn_local(rx.for_each(move |s| {
+			match callback.call1(&callback, &JsValue::from_str(&s)) {
+				Ok(_) => Ok(()),
+				Err(_) => Err(()),
+			}
+		}).then(move |v| {
+			// We need to keep `rpc_session` alive.
+			debug!("RPC subscription has ended");
+			drop(rpc_session);
+			v
+		}));
+	}
+}
diff --git a/node/cli/src/lib.rs b/node/cli/src/lib.rs
index ad79485209689..65accabb1f9cb 100644
--- a/node/cli/src/lib.rs
+++ b/node/cli/src/lib.rs
@@ -23,9 +23,12 @@ pub mod chain_spec;
 
 #[macro_use]
 mod service;
+mod browser;
 mod cli;
 mod factory_impl;
 
+#[cfg(feature = "browser")]
+pub use browser::*;
 #[cfg(feature = "cli")]
 pub use cli::*;
 

From 40b0dd11d957b313b79858ebc5fa77d343fbb99f Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Wed, 30 Oct 2019 18:14:51 +0100
Subject: [PATCH 04/14] More work on browser node

---
 node/cli/browser-demo/index.html | 4 ++--
 node/cli/src/browser.rs          | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/node/cli/browser-demo/index.html b/node/cli/browser-demo/index.html
index 123f146bf25e0..ba80078c8800f 100644
--- a/node/cli/browser-demo/index.html
+++ b/node/cli/browser-demo/index.html
@@ -5,7 +5,7 @@
 	<title>Substrate node</title>
 	<link rel="shortcut icon" href="/favicon.png" />
 	<script type="module">
-import { start_client, default as init } from './pkg/node_browser.js';
+import { start_client, default as init } from './pkg/node_cli.js';
 import ws from './ws.js';
 
 function log(msg) {
@@ -14,7 +14,7 @@
 
 async function start() {
 	log('Loading WASM');
-	await init('./pkg/node_browser_bg.wasm');
+	await init('./pkg/node_cli_bg.wasm');
 	log('Successfully loaded WASM');
 
 	// Build our client.
diff --git a/node/cli/src/browser.rs b/node/cli/src/browser.rs
index 31db0524b96e1..6a340a580fc3a 100644
--- a/node/cli/src/browser.rs
+++ b/node/cli/src/browser.rs
@@ -28,7 +28,7 @@ use wasm_bindgen::prelude::*;
 #[wasm_bindgen]
 pub fn start_client(wasm_ext: wasm_ext::ffi::Transport) -> Result<Client, JsValue> {
 	start_inner(wasm_ext)
-		.map_err(|err| JsValue::from_str(err.description()))
+		.map_err(|err| JsValue::from_str(&err.to_string()))
 }
 
 fn start_inner(wasm_ext: wasm_ext::ffi::Transport) -> Result<Client, Box<dyn std::error::Error>> {

From ca27dcd63f69c8a53d235021f5773f295f3024e9 Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Wed, 30 Oct 2019 18:25:57 +0100
Subject: [PATCH 05/14] More work

---
 Cargo.lock              | 3 +++
 node/cli/Cargo.toml     | 5 ++++-
 node/cli/src/browser.rs | 6 +++++-
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 4f3db5032fe53..5244444ecd26a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2406,6 +2406,7 @@ dependencies = [
  "hex-literal 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "js-sys 0.3.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "jsonrpc-core 13.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "kvdb-memorydb 0.1.0 (git+https://github.com/paritytech/parity-common?rev=b0317f649ab2c665b7987b8475878fc4d2e1f81d)",
  "libp2p 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "node-executor 2.0.0",
@@ -2413,6 +2414,7 @@ dependencies = [
  "node-rpc 2.0.0",
  "node-runtime 2.0.0",
  "parity-scale-codec 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -3377,6 +3379,7 @@ dependencies = [
  "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
diff --git a/node/cli/Cargo.toml b/node/cli/Cargo.toml
index 171583c100152..d261ab35f3003 100644
--- a/node/cli/Cargo.toml
+++ b/node/cli/Cargo.toml
@@ -76,6 +76,9 @@ console_log = { version = "0.1.2", optional = true }
 js-sys = { version = "0.3.22", optional = true }
 wasm-bindgen = { version = "0.2.45", optional = true }
 wasm-bindgen-futures = { version = "0.3.22", optional = true }
+kvdb-memorydb = { git = "https://github.com/paritytech/parity-common", rev="b0317f649ab2c665b7987b8475878fc4d2e1f81d", optional = true }
+# TODO: need the feature
+rand6 = { package = "rand", version = "0.6", features = ["wasm-bindgen"] }
 
 [dev-dependencies]
 keystore = { package = "substrate-keystore", path = "../../core/keystore" }
@@ -93,6 +96,6 @@ vergen = "3.0.4"
 [features]
 default = ["cli"]
 # TODO: docs
-browser = ["clear_on_drop", "console_error_panic_hook", "console_log", "js-sys", "libp2p", "wasm-bindgen", "wasm-bindgen-futures", "rand/wasm-bindgen"]
+browser = ["clear_on_drop", "console_error_panic_hook", "console_log", "js-sys", "libp2p", "wasm-bindgen", "wasm-bindgen-futures", "kvdb-memorydb", "rand/wasm-bindgen"]
 # TODO: docs
 cli = ["substrate-cli", "transaction-factory", "tokio", "exit-future", "ctrlc", "client_db/kvdb-rocksdb"]
diff --git a/node/cli/src/browser.rs b/node/cli/src/browser.rs
index 6a340a580fc3a..b2b263bd34dcd 100644
--- a/node/cli/src/browser.rs
+++ b/node/cli/src/browser.rs
@@ -21,7 +21,7 @@ use futures::{prelude::*, sync::oneshot, sync::mpsc};
 use libp2p::wasm_ext;
 use log::{debug, info};
 use std::sync::Arc;
-use substrate_service::{AbstractService, RpcSession, Roles as ServiceRoles, Configuration};
+use substrate_service::{AbstractService, RpcSession, Roles as ServiceRoles, Configuration, config::DatabaseConfig};
 use wasm_bindgen::prelude::*;
 
 /// Starts the client.
@@ -46,6 +46,10 @@ fn start_inner(wasm_ext: wasm_ext::ffi::Transport) -> Result<Client, Box<dyn std
 	config.telemetry_external_transport = Some(wasm_ext);
 	config.roles = ServiceRoles::FULL;
 	config.name = "Browser node".to_string();
+    config.database = {
+        let db = Arc::new(kvdb_memorydb::create(10));
+        DatabaseConfig::Custom(db)
+    };
     // TODO: config.database
 
 	//info!("{}", version.name);

From eb5b5c8c9ca26798e9c0526c0f587086bc115554 Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Wed, 30 Oct 2019 20:44:59 +0100
Subject: [PATCH 06/14] More work

---
 .gitlab-ci.yml                   | 2 ++
 node/cli/browser-demo/README.md  | 2 +-
 node/cli/browser-demo/index.html | 3 ---
 node/cli/src/browser.rs          | 9 ++++-----
 4 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 1b944157fe9c5..90a966653d7c8 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -215,6 +215,8 @@ check-web-wasm:
     - time cargo web build -p substrate-state-machine
     - time cargo web build -p substrate-telemetry
     - time cargo web build -p substrate-trie
+    # Note: the command below is a bit weird because several Cargo issues prevent us from compiling the node in a more straight-forward way.
+    - time cargo build --manifest-path=node/cli/Cargo.toml --no-default-features --features "browser" --target=wasm32-unknown-unknown
     - sccache -s
 
 node-exits:
diff --git a/node/cli/browser-demo/README.md b/node/cli/browser-demo/README.md
index cc23023848f02..30470cc27680e 100644
--- a/node/cli/browser-demo/README.md
+++ b/node/cli/browser-demo/README.md
@@ -4,7 +4,7 @@
 cargo install wasm-pack		# If necessary
 
 # From the `node-browser` directory (parent from this README)
-wasm-pack build --target web --out-dir ./demo/pkg --no-typescript --release
+wasm-pack build --target web --out-dir ./demo/pkg --no-typescript --release -- --no-default-features --features "browser"
 
 xdg-open index.html
 ```
diff --git a/node/cli/browser-demo/index.html b/node/cli/browser-demo/index.html
index ba80078c8800f..cf107e64568f2 100644
--- a/node/cli/browser-demo/index.html
+++ b/node/cli/browser-demo/index.html
@@ -29,9 +29,6 @@
 		client
 			.rpcSend('{"method":"system_networkState","params":[],"id":1,"jsonrpc":"2.0"}')
 			.then((r) => log("Network state: " + r));
-		client
-			.rpcSend('{"method":"system_networkState","params":[],"id":1,"jsonrpc":"2.0"}')
-			.then((r) => log("Network state: " + r));
 	}, 1000);
 }
 
diff --git a/node/cli/src/browser.rs b/node/cli/src/browser.rs
index b2b263bd34dcd..bc8aa169051ad 100644
--- a/node/cli/src/browser.rs
+++ b/node/cli/src/browser.rs
@@ -46,11 +46,10 @@ fn start_inner(wasm_ext: wasm_ext::ffi::Transport) -> Result<Client, Box<dyn std
 	config.telemetry_external_transport = Some(wasm_ext);
 	config.roles = ServiceRoles::FULL;
 	config.name = "Browser node".to_string();
-    config.database = {
-        let db = Arc::new(kvdb_memorydb::create(10));
-        DatabaseConfig::Custom(db)
-    };
-    // TODO: config.database
+	config.database = {
+		let db = Arc::new(kvdb_memorydb::create(10));
+		DatabaseConfig::Custom(db)
+	};
 
 	//info!("{}", version.name);
 	info!("  version {}", config.full_version());

From 677b8b56f501b47c7e97db028b51df02bb08b735 Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Wed, 30 Oct 2019 20:59:30 +0100
Subject: [PATCH 07/14] Purge a bit the CI script

---
 .gitlab-ci.yml | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 90a966653d7c8..36391cfb614b0 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -196,25 +196,13 @@ check-web-wasm:
     - time cargo web build -p sr-io
     - time cargo web build -p sr-primitives
     - time cargo web build -p sr-std
-    - time cargo web build -p substrate-chain-spec
     - time cargo web build -p substrate-client
     - time cargo web build -p substrate-consensus-aura
     - time cargo web build -p substrate-consensus-babe
     - time cargo web build -p substrate-consensus-common
-    - time cargo web build -p substrate-keyring
-    - time cargo web build -p substrate-keystore
-    - time cargo web build -p substrate-executor
-    - time cargo web build -p substrate-network
-    - time cargo web build -p substrate-offchain
-    - time cargo web build -p substrate-panic-handler
-    - time cargo web build -p substrate-peerset
-    - time cargo web build -p substrate-primitives
-    - time cargo web build -p substrate-rpc-servers
-    - time cargo web build -p substrate-serializer
-    - time cargo web build -p substrate-state-db
-    - time cargo web build -p substrate-state-machine
+    - time cargo web build -p substrate-finality-grandpa
+    - time cargo web build -p substrate-service
     - time cargo web build -p substrate-telemetry
-    - time cargo web build -p substrate-trie
     # Note: the command below is a bit weird because several Cargo issues prevent us from compiling the node in a more straight-forward way.
     - time cargo build --manifest-path=node/cli/Cargo.toml --no-default-features --features "browser" --target=wasm32-unknown-unknown
     - sccache -s

From bf9c5ed37f117d1231ea2241fbddeb8154dcda4f Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Wed, 30 Oct 2019 21:29:25 +0100
Subject: [PATCH 08/14] More clean up

---
 node/cli/Cargo.toml             | 39 +++++++++++++++++++--------
 node/cli/browser-demo/README.md |  2 +-
 node/cli/src/browser.rs         | 47 +++++++++++++++++++--------------
 node/cli/src/lib.rs             | 10 +++++++
 4 files changed, 66 insertions(+), 32 deletions(-)

diff --git a/node/cli/Cargo.toml b/node/cli/Cargo.toml
index d261ab35f3003..ba8d5fe25cce0 100644
--- a/node/cli/Cargo.toml
+++ b/node/cli/Cargo.toml
@@ -23,11 +23,8 @@ crate-type = ["cdylib", "rlib"]
 
 [dependencies]
 log = "0.4.8"
-tokio = { version = "0.1.22", optional = true }
 futures = "0.1.29"
-exit-future = { version = "0.1.4", optional = true }
 jsonrpc-core = "13.2.0"
-substrate-cli = { path = "../../core/cli", optional = true }
 codec = { package = "parity-scale-codec", version = "1.0.0" }
 sr-io = { path = "../../core/sr-io" }
 client = { package = "substrate-client", path = "../../core/client" }
@@ -51,7 +48,6 @@ sr-primitives = { path = "../../core/sr-primitives" }
 node-executor = { path = "../executor" }
 substrate-telemetry = { package = "substrate-telemetry", path = "../../core/telemetry" }
 structopt = "0.3.3"
-transaction-factory = { path = "../../test-utils/transaction-factory", optional = true }
 keyring = { package = "substrate-keyring", path = "../../core/keyring" }
 indices = { package = "srml-indices", path = "../../srml/indices" }
 timestamp = { package = "srml-timestamp", path = "../../srml/timestamp", default-features = false }
@@ -66,19 +62,24 @@ im_online = { package = "srml-im-online", path = "../../srml/im-online", default
 serde = { version = "1.0.101", features = [ "derive" ] }
 client_db = { package = "substrate-client-db", path = "../../core/client/db", default-features = false }
 offchain = { package = "substrate-offchain", path = "../../core/offchain" }
+
+# CLI-specific dependencies
+tokio = { version = "0.1.22", optional = true }
+exit-future = { version = "0.1.4", optional = true }
+substrate-cli = { path = "../../core/cli", optional = true }
+transaction-factory = { path = "../../test-utils/transaction-factory", optional = true }
 ctrlc = { version = "3.1.3", features = ["termination"], optional = true }
 
 # WASM-specific dependencies
 libp2p = { version = "0.12.0", default-features = false, optional = true }
-clear_on_drop = { version = "0.2.3", features = ["no_cc"], optional = true }
+clear_on_drop = { version = "0.2.3", features = ["no_cc"], optional = true }	# Imported just for the `no_cc` feature
 console_error_panic_hook = { version = "0.1.1", optional = true }
 console_log = { version = "0.1.2", optional = true }
 js-sys = { version = "0.3.22", optional = true }
 wasm-bindgen = { version = "0.2.45", optional = true }
 wasm-bindgen-futures = { version = "0.3.22", optional = true }
 kvdb-memorydb = { git = "https://github.com/paritytech/parity-common", rev="b0317f649ab2c665b7987b8475878fc4d2e1f81d", optional = true }
-# TODO: need the feature
-rand6 = { package = "rand", version = "0.6", features = ["wasm-bindgen"] }
+rand6 = { package = "rand", version = "0.6", features = ["wasm-bindgen"], optional = true }	# Imported just for the `wasm-bindgen` feature
 
 [dev-dependencies]
 keystore = { package = "substrate-keystore", path = "../../core/keystore" }
@@ -95,7 +96,23 @@ vergen = "3.0.4"
 
 [features]
 default = ["cli"]
-# TODO: docs
-browser = ["clear_on_drop", "console_error_panic_hook", "console_log", "js-sys", "libp2p", "wasm-bindgen", "wasm-bindgen-futures", "kvdb-memorydb", "rand/wasm-bindgen"]
-# TODO: docs
-cli = ["substrate-cli", "transaction-factory", "tokio", "exit-future", "ctrlc", "client_db/kvdb-rocksdb"]
+browser = [
+	"clear_on_drop",
+	"console_error_panic_hook",
+	"console_log",
+	"js-sys",
+	"libp2p",
+	"wasm-bindgen",
+	"wasm-bindgen-futures",
+	"kvdb-memorydb",
+	"rand/wasm-bindgen",
+	"rand6"
+]
+cli = [
+	"substrate-cli",
+	"transaction-factory",
+	"tokio",
+	"exit-future",
+	"ctrlc",
+	"client_db/kvdb-rocksdb"
+]
diff --git a/node/cli/browser-demo/README.md b/node/cli/browser-demo/README.md
index 30470cc27680e..4faebcbc76df4 100644
--- a/node/cli/browser-demo/README.md
+++ b/node/cli/browser-demo/README.md
@@ -3,7 +3,7 @@
 ```sh
 cargo install wasm-pack		# If necessary
 
-# From the `node-browser` directory (parent from this README)
+# From the `node/cli` directory (parent from this README)
 wasm-pack build --target web --out-dir ./demo/pkg --no-typescript --release -- --no-default-features --features "browser"
 
 xdg-open index.html
diff --git a/node/cli/src/browser.rs b/node/cli/src/browser.rs
index bc8aa169051ad..802786edcc8a5 100644
--- a/node/cli/src/browser.rs
+++ b/node/cli/src/browser.rs
@@ -25,6 +25,8 @@ use substrate_service::{AbstractService, RpcSession, Roles as ServiceRoles, Conf
 use wasm_bindgen::prelude::*;
 
 /// Starts the client.
+///
+/// You must pass a libp2p transport that supports .
 #[wasm_bindgen]
 pub fn start_client(wasm_ext: wasm_ext::ffi::Transport) -> Result<Client, JsValue> {
 	start_inner(wasm_ext)
@@ -35,35 +37,40 @@ fn start_inner(wasm_ext: wasm_ext::ffi::Transport) -> Result<Client, Box<dyn std
 	console_error_panic_hook::set_once();
 	console_log::init_with_level(log::Level::Info);
 
-	let wasm_ext = wasm_ext::ExtTransport::new(wasm_ext);
-
-	let chain_spec = ChainSpec::FlamingFir.load().map_err(|e| format!("{:?}", e))?;
-	let mut config = Configuration::<(), _, _>::default_with_spec(chain_spec);
-	config.network.transport = network::config::TransportConfig::Normal {
-		wasm_external_transport: Some(wasm_ext.clone()),
-		enable_mdns: false,
-	};
-	config.telemetry_external_transport = Some(wasm_ext);
-	config.roles = ServiceRoles::FULL;
-	config.name = "Browser node".to_string();
-	config.database = {
-		let db = Arc::new(kvdb_memorydb::create(10));
-		DatabaseConfig::Custom(db)
+	// Build the configuration to pass to the service.
+	let config = {
+		let wasm_ext = wasm_ext::ExtTransport::new(wasm_ext);
+		let chain_spec = ChainSpec::FlamingFir.load().map_err(|e| format!("{:?}", e))?;
+		let mut config = Configuration::<(), _, _>::default_with_spec(chain_spec);
+		config.network.transport = network::config::TransportConfig::Normal {
+			wasm_external_transport: Some(wasm_ext.clone()),
+			enable_mdns: false,
+		};
+		config.telemetry_external_transport = Some(wasm_ext);
+		config.roles = ServiceRoles::LIGHT;
+		config.name = "Browser node".to_string();
+		config.database = {
+			let db = Arc::new(kvdb_memorydb::create(10));
+			DatabaseConfig::Custom(db)
+		};
+		config
 	};
 
-	//info!("{}", version.name);
+	info!("Substrate browser node");
 	info!("  version {}", config.full_version());
 	info!("  by Parity Technologies, 2017-2019");
 	info!("Chain specification: {}", config.chain_spec.name());
 	info!("Node name: {}", config.name);
 	info!("Roles: {:?}", config.roles);
 
-	let mut service = new_full!(config)
-		.map_err(|e: String| format!("{:?}", e))?.0;
-
-	/*let informant = substrate_cli::informant::build(&service);
-	wasm_bindgen_futures::spawn_local(informant);*/
+	// Create the service. This is the most heavy initialization step.
+	let mut service = crate::service::new_light(config).map_err(|e| format!("{:?}", e))?;
 
+	// We now dispatch a background task responsible for processing the service.
+	//
+	// The main action performed by the code below consists in polling the service with
+	// `service.poll()`.
+	// The rest consists in handling RPC requests.
 	let (rpc_send_tx, mut rpc_send_rx) = mpsc::unbounded::<RpcMessage>();
 	wasm_bindgen_futures::spawn_local(futures::future::poll_fn(move || {
 		loop {
diff --git a/node/cli/src/lib.rs b/node/cli/src/lib.rs
index 65accabb1f9cb..d22087c8f47d6 100644
--- a/node/cli/src/lib.rs
+++ b/node/cli/src/lib.rs
@@ -15,6 +15,16 @@
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
 //! Substrate CLI library.
+//!
+//! This package has two Cargo features:
+//!
+//! - `cli` (default): exposes functions that parse command-line options, then start and run the
+//! node as a CLI application.
+//!
+//! - `browser`: exposes the content of the `browser` module, which consists of exported symbols
+//! that are meant to be passed through the `wasm-bindgen` utility and called from JavaScript.
+//! Despite its name the produced WASM can theoretically also be used from NodeJS, although this
+//! hasn't been tested.
 
 #![warn(missing_docs)]
 #![warn(unused_extern_crates)]

From c49401fb92c0d30b36f157ef71b38954bec380e3 Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Wed, 30 Oct 2019 21:40:54 +0100
Subject: [PATCH 09/14] Remove substrate-finality-grandpa from the CI

Its tests use tokio, which fails to compile.
---
 .gitlab-ci.yml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 36391cfb614b0..afff58f14362f 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -200,7 +200,6 @@ check-web-wasm:
     - time cargo web build -p substrate-consensus-aura
     - time cargo web build -p substrate-consensus-babe
     - time cargo web build -p substrate-consensus-common
-    - time cargo web build -p substrate-finality-grandpa
     - time cargo web build -p substrate-service
     - time cargo web build -p substrate-telemetry
     # Note: the command below is a bit weird because several Cargo issues prevent us from compiling the node in a more straight-forward way.

From 84f339251e405cf386a9d787d53c15708048bc13 Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Thu, 31 Oct 2019 10:50:03 +0100
Subject: [PATCH 10/14] Address review

---
 node/cli/browser-demo/build.sh | 5 ++---
 node/cli/src/browser.rs        | 2 --
 node/cli/src/cli.rs            | 2 --
 node/cli/src/factory_impl.rs   | 2 --
 node/cli/src/lib.rs            | 3 +++
 5 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/node/cli/browser-demo/build.sh b/node/cli/browser-demo/build.sh
index 5b34edeb4c08d..c16100794ad2e 100755
--- a/node/cli/browser-demo/build.sh
+++ b/node/cli/browser-demo/build.sh
@@ -1,4 +1,3 @@
-cd ..
-wasm-pack build --target web --out-dir ./browser-demo/pkg --no-typescript --release -- --no-default-features --features "browser"
-cd browser-demo
+#!/usr/bin/env sh
+wasm-pack build --target web --out-dir ./browser-demo/pkg --no-typescript --release ./.. -- --no-default-features --features "browser"
 python -m SimpleHTTPServer 8000
diff --git a/node/cli/src/browser.rs b/node/cli/src/browser.rs
index 802786edcc8a5..02d999995d366 100644
--- a/node/cli/src/browser.rs
+++ b/node/cli/src/browser.rs
@@ -14,8 +14,6 @@
 // You should have received a copy of the GNU General Public License
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
-#![cfg(feature = "browser")]
-
 use crate::ChainSpec;
 use futures::{prelude::*, sync::oneshot, sync::mpsc};
 use libp2p::wasm_ext;
diff --git a/node/cli/src/cli.rs b/node/cli/src/cli.rs
index 3f8c9c5657f7a..2e5d27cec7a5f 100644
--- a/node/cli/src/cli.rs
+++ b/node/cli/src/cli.rs
@@ -14,8 +14,6 @@
 // You should have received a copy of the GNU General Public License
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
-#![cfg(feature = "cli")]
-
 pub use substrate_cli::error;
 use tokio::prelude::Future;
 use tokio::runtime::{Builder as RuntimeBuilder, Runtime};
diff --git a/node/cli/src/factory_impl.rs b/node/cli/src/factory_impl.rs
index 6578350a5a6dd..48fb7b237f1e6 100644
--- a/node/cli/src/factory_impl.rs
+++ b/node/cli/src/factory_impl.rs
@@ -18,8 +18,6 @@
 //! using the cli to manufacture transactions and distribute them
 //! to accounts.
 
-#![cfg(feature = "cli")]
-
 use rand::{Rng, SeedableRng};
 use rand::rngs::StdRng;
 
diff --git a/node/cli/src/lib.rs b/node/cli/src/lib.rs
index d22087c8f47d6..78660ae92e3c5 100644
--- a/node/cli/src/lib.rs
+++ b/node/cli/src/lib.rs
@@ -33,8 +33,11 @@ pub mod chain_spec;
 
 #[macro_use]
 mod service;
+#[cfg(feature = "browser")]
 mod browser;
+#[cfg(feature = "cli")]
 mod cli;
+#[cfg(feature = "cli")]
 mod factory_impl;
 
 #[cfg(feature = "browser")]

From 708a59ea0972f27a433a6c5b6587f3f842d79542 Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Thu, 31 Oct 2019 11:00:33 +0100
Subject: [PATCH 11/14] Add rocksdb feature to the service

---
 core/cli/Cargo.toml          | 2 +-
 core/service/Cargo.toml      | 6 ++++++
 core/service/test/Cargo.toml | 2 +-
 node/cli/Cargo.toml          | 4 ++--
 4 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/core/cli/Cargo.toml b/core/cli/Cargo.toml
index a2723484ad4c1..2298bba0b711f 100644
--- a/core/cli/Cargo.toml
+++ b/core/cli/Cargo.toml
@@ -28,7 +28,7 @@ header-metadata = { package = "substrate-header-metadata", path = "../../core/cl
 network = { package = "substrate-network", path = "../../core/network" }
 sr-primitives = { path = "../../core/sr-primitives" }
 primitives = { package = "substrate-primitives", path = "../../core/primitives" }
-service = { package = "substrate-service", path = "../../core/service" }
+service = { package = "substrate-service", path = "../../core/service", default-features = false }
 state-machine = { package = "substrate-state-machine", path = "../../core/state-machine" }
 substrate-telemetry = { path = "../../core/telemetry" }
 keyring = { package = "substrate-keyring", path = "../keyring" }
diff --git a/core/service/Cargo.toml b/core/service/Cargo.toml
index 76d68eb45f94f..1a85ed8de0f70 100644
--- a/core/service/Cargo.toml
+++ b/core/service/Cargo.toml
@@ -4,6 +4,12 @@ version = "2.0.0"
 authors = ["Parity Technologies <admin@parity.io>"]
 edition = "2018"
 
+[features]
+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 = ["client_db/kvdb-rocksdb"]
+
 [dependencies]
 derive_more = "0.15.0"
 futures = "0.1.29"
diff --git a/core/service/test/Cargo.toml b/core/service/test/Cargo.toml
index 872d63415f4e8..4415369a6a1d3 100644
--- a/core/service/test/Cargo.toml
+++ b/core/service/test/Cargo.toml
@@ -12,7 +12,7 @@ log = "0.4.8"
 env_logger = "0.7.0"
 fdlimit = "0.1.1"
 futures03 = { package = "futures-preview", version = "=0.3.0-alpha.19", features = ["compat"] }
-service = { package = "substrate-service", path = "../../../core/service" }
+service = { package = "substrate-service", path = "../../../core/service", default-features = false }
 network = { package = "substrate-network", path = "../../../core/network" }
 consensus = { package = "substrate-consensus-common", path = "../../../core/consensus/common" }
 client = { package = "substrate-client", path = "../../../core/client" }
diff --git a/node/cli/Cargo.toml b/node/cli/Cargo.toml
index ba8d5fe25cce0..99a4c6aebfb85 100644
--- a/node/cli/Cargo.toml
+++ b/node/cli/Cargo.toml
@@ -36,7 +36,7 @@ node-primitives = { path = "../primitives" }
 hex-literal = "0.2.1"
 substrate-rpc = { package = "substrate-rpc", path = "../../core/rpc" }
 substrate-basic-authorship = { path = "../../core/basic-authorship" }
-substrate-service = { path = "../../core/service" }
+substrate-service = { path = "../../core/service", default-features = false }
 chain-spec = { package = "substrate-chain-spec", path = "../../core/chain-spec" }
 transaction_pool = { package = "substrate-transaction-pool", path = "../../core/transaction-pool" }
 network = { package = "substrate-network", path = "../../core/network" }
@@ -114,5 +114,5 @@ cli = [
 	"tokio",
 	"exit-future",
 	"ctrlc",
-	"client_db/kvdb-rocksdb"
+	"substrate-service/rocksdb"
 ]

From fdb4f768e30dc38dee6b0bac86b083f82c68ebe9 Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Thu, 31 Oct 2019 11:08:19 +0100
Subject: [PATCH 12/14] Fix substrate-service WASM CI

---
 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index afff58f14362f..2564905447447 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -200,7 +200,7 @@ check-web-wasm:
     - time cargo web build -p substrate-consensus-aura
     - time cargo web build -p substrate-consensus-babe
     - time cargo web build -p substrate-consensus-common
-    - time cargo web build -p substrate-service
+    - time cargo web build -p substrate-service --no-default-features
     - time cargo web build -p substrate-telemetry
     # Note: the command below is a bit weird because several Cargo issues prevent us from compiling the node in a more straight-forward way.
     - time cargo build --manifest-path=node/cli/Cargo.toml --no-default-features --features "browser" --target=wasm32-unknown-unknown

From e89e188ac8ece48094142a4479eb02132473764f Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Thu, 31 Oct 2019 11:33:38 +0100
Subject: [PATCH 13/14] Apply suggestions from code review
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-Authored-By: Bastian Köcher <bkchr@users.noreply.github.com>
---
 node/cli/browser-demo/ws.js | 2 +-
 node/cli/src/browser.rs     | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/node/cli/browser-demo/ws.js b/node/cli/browser-demo/ws.js
index 320f742a12ade..fa7a499a8a7a3 100644
--- a/node/cli/browser-demo/ws.js
+++ b/node/cli/browser-demo/ws.js
@@ -1,4 +1,4 @@
-// Copyright 2018-2019 Parity Technologies (UK) Ltd.
+// Copyright 2019 Parity Technologies (UK) Ltd.
 // This file is part of Substrate.
 
 // Substrate is free software: you can redistribute it and/or modify
diff --git a/node/cli/src/browser.rs b/node/cli/src/browser.rs
index 02d999995d366..1c84efa107ea7 100644
--- a/node/cli/src/browser.rs
+++ b/node/cli/src/browser.rs
@@ -1,4 +1,4 @@
-// Copyright 2018-2019 Parity Technologies (UK) Ltd.
+// Copyright 2019 Parity Technologies (UK) Ltd.
 // This file is part of Substrate.
 
 // Substrate is free software: you can redistribute it and/or modify

From cbe0f81c9ad5682fb1fe02f3144201f7872ba966 Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Thu, 31 Oct 2019 11:46:29 +0100
Subject: [PATCH 14/14] Don't WASM-compile substrate-service altogether

---
 .gitlab-ci.yml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 2564905447447..10b293acd8bac 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -200,7 +200,6 @@ check-web-wasm:
     - time cargo web build -p substrate-consensus-aura
     - time cargo web build -p substrate-consensus-babe
     - time cargo web build -p substrate-consensus-common
-    - time cargo web build -p substrate-service --no-default-features
     - time cargo web build -p substrate-telemetry
     # Note: the command below is a bit weird because several Cargo issues prevent us from compiling the node in a more straight-forward way.
     - time cargo build --manifest-path=node/cli/Cargo.toml --no-default-features --features "browser" --target=wasm32-unknown-unknown