Add a command to purge the relay chain only (#306)

* Add a command to purge the relay chain only

* WIP

* Update rococo-parachains/src/cli.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* Move cli stuff to its own crate

* Copyright dates

* Test not working for some reason...

* WIP

* Revert "WIP"

This reverts commit f97cd63742c7df822e4a6e52a29db5e0f56b7bfa.

* Fix test to use provided relay chain

* Apply suggestions from code review

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* Add hint about which database could not be purged

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

cumulus/rococo-parachains/tests/common.rs

@@ -1,4 +1,4 @@
-// Copyright 2020 Parity Technologies (UK) Ltd.
+// Copyright 2020-2021 Parity Technologies (UK) Ltd.
 // This file is part of Substrate.
 
 // Substrate is free software: you can redistribute it and/or modify

cumulus/rococo-parachains/tests/polkadot_argument_parsing.rs

@@ -1,4 +1,4 @@
-// Copyright 2020 Parity Technologies (UK) Ltd.
+// Copyright 2020-2021 Parity Technologies (UK) Ltd.
 // This file is part of Substrate.
 
 // Substrate is free software: you can redistribute it and/or modify

cumulus/rococo-parachains/tests/polkadot_mdns_issue.rs

@@ -1,4 +1,4 @@
-// Copyright 2020 Parity Technologies (UK) Ltd.
+// Copyright 2020-2021 Parity Technologies (UK) Ltd.
 // This file is part of Substrate.
 
 // Substrate is free software: you can redistribute it and/or modify

cumulus/rococo-parachains/tests/purge_chain_works.rs

@@ -1,4 +1,4 @@
-// Copyright 2020 Parity Technologies (UK) Ltd.
+// Copyright 2020-2021 Parity Technologies (UK) Ltd.
 // This file is part of Substrate.
 
 // Substrate is free software: you can redistribute it and/or modify
@@ -15,50 +15,63 @@
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
 use assert_cmd::cargo::cargo_bin;
-use std::{convert::TryInto, fs, path::PathBuf, process::Command, thread, time::Duration};
+use std::{convert::TryInto, process::Command, thread, time::Duration};
 
 mod common;
 
 #[test]
 #[cfg(unix)]
 fn purge_chain_works() {
-	use nix::{
-		sys::signal::{kill, Signal::SIGINT},
-		unistd::Pid,
-	};
+	fn run_node_and_stop() -> tempfile::TempDir {
+		use nix::{
+			sys::signal::{kill, Signal::SIGINT},
+			unistd::Pid,
+		};
 
-	let base_path = "purge_chain_test";
+		let base_path = tempfile::tempdir().unwrap();
 
-	let _ = fs::remove_dir_all(base_path);
-	let mut cmd = Command::new(cargo_bin("rococo-collator"))
-		.args(&["-d", base_path, "--", "--dev"])
-		.spawn()
-		.unwrap();
+		let mut cmd = Command::new(cargo_bin("rococo-collator"))
+			.args(&["-d"])
+			.arg(base_path.path())
+			.args(&["--"])
+			.spawn()
+			.unwrap();
 
-	// Let it produce some blocks.
-	thread::sleep(Duration::from_secs(30));
-	assert!(
-		cmd.try_wait().unwrap().is_none(),
-		"the process should still be running"
-	);
+		// Let it produce some blocks.
+		thread::sleep(Duration::from_secs(30));
+		assert!(
+			cmd.try_wait().unwrap().is_none(),
+			"the process should still be running"
+		);
 
-	// Stop the process
-	kill(Pid::from_raw(cmd.id().try_into().unwrap()), SIGINT).unwrap();
-	assert!(common::wait_for(&mut cmd, 30)
-		.map(|x| x.success())
-		.unwrap_or_default());
+		// Stop the process
+		kill(Pid::from_raw(cmd.id().try_into().unwrap()), SIGINT).unwrap();
+		assert!(common::wait_for(&mut cmd, 30)
+			.map(|x| x.success())
+			.unwrap_or_default());
 
-	let status = Command::new(cargo_bin("rococo-collator"))
-		.args(&["purge-chain", "-d", base_path, "-y"])
-		.status()
-		.unwrap();
-	assert!(status.success());
+		base_path
+	}
 
-	// Make sure that the `parachain_local_testnet` chain folder exists, but the `db` is deleted.
-	assert!(PathBuf::from(base_path)
-		.join("chains/local_testnet/")
-		.exists());
-	assert!(!PathBuf::from(base_path)
-		.join("chains/local_testnet/db")
-		.exists());
+	// Check that both databases are deleted
+	{
+		let base_path = run_node_and_stop();
+
+		assert!(base_path.path().join("chains/local_testnet/db").exists());
+		assert!(base_path.path().join("polkadot/chains/westend_dev/db").exists());
+
+		let status = Command::new(cargo_bin("rococo-collator"))
+			.args(&["purge-chain", "-d"])
+			.arg(base_path.path())
+			.arg("-y")
+			.status()
+			.unwrap();
+		assert!(status.success());
+
+		// Make sure that the `parachain_local_testnet` chain folder exists, but the `db` is deleted.
+		assert!(base_path.path().join("chains/local_testnet").exists());
+		assert!(!base_path.path().join("chains/local_testnet/db").exists());
+		assert!(base_path.path().join("polkadot/chains/westend_dev").exists());
+		assert!(!base_path.path().join("polkadot/chains/westend_dev/db").exists());
+	}
 }

cumulus/rococo-parachains/tests/running_the_node_and_interrupt.rs

@@ -1,4 +1,4 @@
-// Copyright 2020 Parity Technologies (UK) Ltd.
+// Copyright 2020-2021 Parity Technologies (UK) Ltd.
 // This file is part of Substrate.
 
 // Substrate is free software: you can redistribute it and/or modify