Replace dev chain special case with preset

Add --min-gas-price (does the same as legacy --gasprice) and tweak
gas_pricer_config() and test cases.  Dev preset will still be
overridden by CLI arguments, including --gasprice.

parity/cli/config.full.toml

@@ -101,6 +101,7 @@ reseal_min_period = 4000
 reseal_max_period = 60000
 work_queue_size = 20
 relay_set = "cheap"
+min_gas_price = ""
 usd_per_tx = "0.0025"
 usd_per_eth = "auto"
 price_update_period = "hourly"

parity/cli/mod.rs

@@ -269,6 +269,8 @@ usage! {
 			or |c: &Config| otry!(c.mining).tx_time_limit.clone().map(Some),
 		flag_relay_set: String = "cheap",
 			or |c: &Config| otry!(c.mining).relay_set.clone(),
+		flag_min_gas_price: Option<String> = None,
+			or |c: &Config| otry!(c.mining).min_gas_price.clone().map(Some),
 		flag_usd_per_tx: String = "0.0025",
 			or |c: &Config| otry!(c.mining).usd_per_tx.clone(),
 		flag_usd_per_eth: String = "auto",
@@ -542,6 +544,7 @@ struct Mining {
 	tx_gas_limit: Option<String>,
 	tx_time_limit: Option<u64>,
 	relay_set: Option<String>,
+	min_gas_price: Option<String>,
 	usd_per_tx: Option<String>,
 	usd_per_eth: Option<String>,
 	price_update_period: Option<String>,
@@ -808,6 +811,7 @@ mod tests {
 			flag_tx_gas_limit: Some("6283184".into()),
 			flag_tx_time_limit: Some(100u64),
 			flag_relay_set: "cheap".into(),
+			flag_min_gas_price: Some("".into()),
 			flag_usd_per_tx: "0.0025".into(),
 			flag_usd_per_eth: "auto".into(),
 			flag_price_update_period: "hourly".into(),
@@ -1035,6 +1039,7 @@ mod tests {
 				reseal_max_period: Some(60000),
 				work_queue_size: None,
 				relay_set: None,
+				min_gas_price: None,
 				usd_per_tx: None,
 				usd_per_eth: None,
 				price_update_period: Some("hourly".into()),

parity/cli/presets/config.dev.toml

@@ -0,0 +1,6 @@
+[parity]
+chain = "dev"
+
+[mining]
+reseal_min_period = 0
+min_gas_price = "0"

parity/cli/presets/mod.rs

@@ -16,8 +16,7 @@
 
 pub fn preset_config_string(arg: &str) -> Result<&'static str, &str> {
     match arg.to_lowercase().as_ref() {
-        "poa" => Ok(include_str!("./config.poa.toml")),
-        "pow" => Ok(include_str!("./config.pow.toml")),
+        "dev" => Ok(include_str!("./config.dev.toml")),
         _ => Err(arg.clone())
     }
 }

parity/cli/usage.txt

@@ -295,6 +295,10 @@ Sealing/Mining Options:
                                    means we relay nothing if not mining);
                                    lenient - Same as strict when mining, and cheap
                                    when not (default: {flag_relay_set}).
+  --min-gas-price STRING           Minimum amount of Wei per GAS to be paid for a
+                                   transaction to be accepted for mining. Overrides
+                                   --basic-tx-usd.
+                                   (default: {flag_min_gas_price:?})
   --usd-per-tx USD                 Amount of USD to be paid for a basic transaction
                                    (default: {flag_usd_per_tx}). The minimum gas price is set
                                    accordingly.

parity/configuration.rs

@@ -36,7 +36,7 @@ use parity_rpc::NetworkSettings;
 use cache::CacheConfig;
 use helpers::{to_duration, to_mode, to_block_id, to_u256, to_pending_set, to_price, replace_home, replace_home_and_local,
 geth_ipc_path, parity_ipc_path, to_bootnodes, to_addresses, to_address, to_gas_limit, to_queue_strategy};
-use params::{SpecType, ResealPolicy, AccountsConfig, GasPricerConfig, MinerExtras, Pruning, Switch};
+use params::{ResealPolicy, AccountsConfig, GasPricerConfig, MinerExtras, Pruning, Switch};
 use ethcore_logger::Config as LogConfig;
 use dir::{self, Directories, default_hypervisor_path, default_local_path, default_data_path};
 use dapps::Configuration as DappsConfiguration;
@@ -332,12 +332,6 @@ impl Configuration {
 
 			let verifier_settings = self.verifier_settings();
 
-			// Special presets are present for the dev chain.
-			let (gas_pricer, miner_options) = match spec {
-				SpecType::Dev => (GasPricerConfig::Fixed(0.into()), self.miner_options(0)?),
-				_ => (self.gas_pricer_config()?, self.miner_options(self.args.flag_reseal_min_period)?),
-			};
-
 			let run_cmd = RunCmd {
 				cache_config: cache_config,
 				dirs: dirs,
@@ -347,14 +341,14 @@ impl Configuration {
 				pruning_memory: self.args.flag_pruning_memory,
 				daemon: daemon,
 				logger_config: logger_config.clone(),
-				miner_options: miner_options,
+				miner_options: self.miner_options(self.args.flag_reseal_min_period)?,
 				ws_conf: ws_conf,
 				http_conf: http_conf,
 				ipc_conf: ipc_conf,
 				net_conf: net_conf,
 				network_id: network_id,
 				acc_conf: self.accounts_config()?,
-				gas_pricer: gas_pricer,
+				gas_pricer: self.gas_pricer_config()?,
 				miner_extras: self.miner_extras()?,
 				stratum: self.stratum_options()?,
 				update_policy: update_policy,
@@ -625,8 +619,10 @@ impl Configuration {
 			U256::from_dec_str(&format!("{:.0}", wei_per_gas)).unwrap()
 		}
 
-		if let Some(d) = self.args.flag_gasprice.as_ref() {
-			return Ok(GasPricerConfig::Fixed(to_u256(d)?));
+		if let Some(dec) = self.args.flag_gasprice.as_ref() {
+			return Ok(GasPricerConfig::Fixed(to_u256(dec)?));
+		} else if let Some(dec) = self.args.flag_min_gas_price.as_ref() {
+			return Ok(GasPricerConfig::Fixed(to_u256(dec)?));
 		}
 
 		let usd_per_tx = to_price(&self.args.flag_usd_per_tx)?;
@@ -1586,9 +1582,9 @@ mod tests {
 	}
 
 	#[test]
-	fn test_dev_chain() {
-		let args = vec!["parity", "--chain", "dev"];
-		let conf = parse(&args);
+	fn test_dev_preset() {
+		let args = vec!["parity", "preset", "dev"];
+		let conf = Configuration::parse(&args, None).unwrap();
 		match conf.into_command().unwrap().cmd {
 			Cmd::Run(c) => {
 				assert_eq!(c.gas_pricer, GasPricerConfig::Fixed(0.into()));