Make CLI state pruning optional again

bin/node/cli/tests/common.rs

@@ -161,6 +161,7 @@ pub fn find_ws_url_from_output(read: impl Read + Send) -> (String, String) {
 			let line =
 				line.expect("failed to obtain next line from stdout for WS address discovery");
 			data.push_str(&line);
+			data.push_str("\n");
 
 			// does the line contain our port (we expect this specific output from substrate).
 			let sock_addr = match line.split_once("Running JSON-RPC WS server: addr=") {
@@ -170,7 +171,10 @@ pub fn find_ws_url_from_output(read: impl Read + Send) -> (String, String) {
 
 			Some(format!("ws://{}", sock_addr))
 		})
-		.expect("We should get a WebSocket address");
+		.unwrap_or_else(|| {
+			eprintln!("Observed node output:\n{}", data);
+			panic!("We should get a WebSocket address")
+		});
 
 	(ws_url, data)
 }

bin/node/cli/tests/remember_state_pruning_works.rs

@@ -0,0 +1,38 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2022 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
+
+// This program 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.
+
+// This program 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 this program. If not, see <https://www.gnu.org/licenses/>.
+
+use tempfile::tempdir;
+
+pub mod common;
+
+#[tokio::test]
+#[cfg(unix)]
+async fn remember_state_pruning_works() {
+	let base_path = tempdir().expect("could not create a temp dir");
+
+	// First run with `--state-pruning=archive`.
+	common::run_node_for_a_while(
+		base_path.path(),
+		&["--dev", "--state-pruning=archive", "--no-hardware-benchmarks"],
+	)
+	.await;
+
+	// Then run again without specifying the state pruning.
+	// This should load state pruning settings from the db.
+	common::run_node_for_a_while(base_path.path(), &["--dev", "--no-hardware-benchmarks"]).await;
+}

client/cli/src/params/pruning_params.rs

@@ -28,21 +28,44 @@ pub struct PruningParams {
 	/// This mode specifies when the block's state (ie, storage)
 	/// should be pruned (ie, removed) from the database.
 	///
+	/// This setting can only be set on the first creation of the database. Every subsequent run
+	/// will load the pruning mode from the database and will error if the stored mode doesn't
+	/// match this CLI value. It is fine to drop this CLI flag for subsequent runs.
+	///
 	/// Possible values:
-	///  'archive'            Keep the state of all blocks.
-	///  'archive-canonical'  Keep only the state of finalized blocks.
-	///   number              Keep the state of the last number of finalized blocks.
-	#[arg(alias = "pruning", long, value_name = "PRUNING_MODE", default_value = "256")]
-	pub state_pruning: DatabasePruningMode,
+	///
+	///  - archive:
+	///
+	///    Keep the state of all blocks.
+	///
+	///  - 'archive-canonical'
+	///
+	///    Keep only the state of finalized blocks.
+	///
+	///  - number
+	///
+	///    Keep the state of the last number of finalized blocks.
+	///
+	/// [default: 256]
+	#[arg(alias = "pruning", long, value_name = "PRUNING_MODE")]
+	pub state_pruning: Option<DatabasePruningMode>,
 	/// Specify the blocks pruning mode.
 	///
 	/// This mode specifies when the block's body (including justifications)
 	/// should be pruned (ie, removed) from the database.
 	///
 	/// Possible values:
-	///  'archive'            Keep all blocks.
-	///  'archive-canonical'  Keep only finalized blocks.
-	///   number              Keep the last `number` of finalized blocks.
+	///  - 'archive'
+	///
+	///    Keep all blocks.
+	///
+	///  - 'archive-canonical'
+	///
+	///    Keep only finalized blocks.
+	///
+	///  - number
+	///
+	///  Keep the last `number` of finalized blocks.
 	#[arg(
 		alias = "keep-blocks",
 		long,
@@ -55,7 +78,7 @@ pub struct PruningParams {
 impl PruningParams {
 	/// Get the pruning value from the parameters
 	pub fn state_pruning(&self) -> error::Result<Option<PruningMode>> {
-		Ok(Some(self.state_pruning.into()))
+		Ok(self.state_pruning.map(|v| v.into()))
 	}
 
 	/// Get the block pruning value from the parameters