Augmented node template docs (#6721)

substrate/bin/node-template/node/src/chain_spec.rs

@@ -8,13 +8,13 @@ use sp_finality_grandpa::AuthorityId as GrandpaId;
 use sp_runtime::traits::{Verify, IdentifyAccount};
 use sc_service::ChainType;
 
-// Note this is the URL for the telemetry server
-//const STAGING_TELEMETRY_URL: &str = "wss://telemetry.polkadot.io/submit/";
+// The URL for the telemetry server.
+// const STAGING_TELEMETRY_URL: &str = "wss://telemetry.polkadot.io/submit/";
 
 /// Specialized `ChainSpec`. This is a specialization of the general Substrate ChainSpec type.
 pub type ChainSpec = sc_service::GenericChainSpec<GenesisConfig>;
 
-/// Helper function to generate a crypto pair from seed
+/// Generate a crypto pair from seed.
 pub fn get_from_seed<TPublic: Public>(seed: &str) -> <TPublic::Pair as Pair>::Public {
 	TPublic::Pair::from_string(&format!("//{}", seed), None)
 		.expect("static values are valid; qed")
@@ -23,14 +23,14 @@ pub fn get_from_seed<TPublic: Public>(seed: &str) -> <TPublic::Pair as Pair>::Pu
 
 type AccountPublic = <Signature as Verify>::Signer;
 
-/// Helper function to generate an account ID from seed
+/// Generate an account ID from seed.
 pub fn get_account_id_from_seed<TPublic: Public>(seed: &str) -> AccountId where
 	AccountPublic: From<<TPublic::Pair as Pair>::Public>
 {
 	AccountPublic::from(get_from_seed::<TPublic>(seed)).into_account()
 }
 
-/// Helper function to generate an authority key for Aura
+/// Generate an Aura authority key.
 pub fn authority_keys_from_seed(s: &str) -> (AuraId, GrandpaId) {
 	(
 		get_from_seed::<AuraId>(s),
@@ -42,15 +42,20 @@ pub fn development_config() -> Result<ChainSpec, String> {
 	let wasm_binary = WASM_BINARY.ok_or("Development wasm binary not available".to_string())?;
 
 	Ok(ChainSpec::from_genesis(
+		// Name
 		"Development",
+		// ID
 		"dev",
 		ChainType::Development,
 		move || testnet_genesis(
 			wasm_binary,
+			// Initial PoA authorities
 			vec![
 				authority_keys_from_seed("Alice"),
 			],
+			// Sudo account
 			get_account_id_from_seed::<sr25519::Public>("Alice"),
+			// Pre-funded accounts
 			vec![
 				get_account_id_from_seed::<sr25519::Public>("Alice"),
 				get_account_id_from_seed::<sr25519::Public>("Bob"),
@@ -59,10 +64,15 @@ pub fn development_config() -> Result<ChainSpec, String> {
 			],
 			true,
 		),
+		// Bootnodes
 		vec![],
+		// Telemetry
 		None,
+		// Protocol ID
 		None,
+		// Properties
 		None,
+		// Extensions
 		None,
 	))
 }
@@ -71,16 +81,21 @@ pub fn local_testnet_config() -> Result<ChainSpec, String> {
 	let wasm_binary = WASM_BINARY.ok_or("Development wasm binary not available".to_string())?;
 
 	Ok(ChainSpec::from_genesis(
+		// Name
 		"Local Testnet",
+		// ID
 		"local_testnet",
 		ChainType::Local,
 		move || testnet_genesis(
 			wasm_binary,
+			// Initial PoA authorities
 			vec![
 				authority_keys_from_seed("Alice"),
 				authority_keys_from_seed("Bob"),
 			],
+			// Sudo account
 			get_account_id_from_seed::<sr25519::Public>("Alice"),
+			// Pre-funded accounts
 			vec![
 				get_account_id_from_seed::<sr25519::Public>("Alice"),
 				get_account_id_from_seed::<sr25519::Public>("Bob"),
@@ -97,14 +112,20 @@ pub fn local_testnet_config() -> Result<ChainSpec, String> {
 			],
 			true,
 		),
+		// Bootnodes
 		vec![],
+		// Telemetry
 		None,
+		// Protocol ID
 		None,
+		// Properties
 		None,
+		// Extensions
 		None,
 	))
 }
 
+/// Configure initial storage state for FRAME modules.
 fn testnet_genesis(
 	wasm_binary: &[u8],
 	initial_authorities: Vec<(AuraId, GrandpaId)>,
@@ -114,10 +135,12 @@ fn testnet_genesis(
 ) -> GenesisConfig {
 	GenesisConfig {
 		system: Some(SystemConfig {
+			// Add Wasm runtime to storage.
 			code: wasm_binary.to_vec(),
 			changes_trie_config: Default::default(),
 		}),
 		balances: Some(BalancesConfig {
+			// Configure endowed accounts with initial balance of 1 << 60.
 			balances: endowed_accounts.iter().cloned().map(|k|(k, 1 << 60)).collect(),
 		}),
 		aura: Some(AuraConfig {
@@ -127,6 +150,7 @@ fn testnet_genesis(
 			authorities: initial_authorities.iter().map(|x| (x.1.clone(), 1)).collect(),
 		}),
 		sudo: Some(SudoConfig {
+			// Assign network admin rights.
 			key: root_key,
 		}),
 	}