feat: add option to output metadata to a file (#61)

* add option to output metadata to a file in either scale or json encoding

* refactor metadata printing

* cargo clippy --fix and cargo fmt

* don't panic on broken pipe

* update cargo lock

* improve error handling by properly installing eyre and replacing lots of panics and unwraps

* Minor fixes

* Add doc and user goodie

* cargo +nightly clippy --fix

* fix typo

* Generate doc

---------

Co-authored-by: Chevdor <chevdor@users.noreply.github.com>
Co-authored-by: Chevdor <chevdor@gmail.com>

.gitignore

@@ -4,3 +4,4 @@ data
 .env
 scripts/out
 *.gz
+metadata.*

cli/src/main.rs

@@ -1,5 +1,7 @@
 mod opts;
 
+use std::io::Write;
+
 use clap::{crate_name, crate_version, Parser};
 // use color_eyre::owo_colors::OwoColorize;
 use env_logger::Env;
@@ -20,6 +22,8 @@ macro_rules! noquiet {
 fn main() -> color_eyre::Result<()> {
 	env_logger::Builder::from_env(Env::default().default_filter_or("none")).init();
 	let opts: Opts = Opts::parse();
+	color_eyre::install()?;
+
 	noquiet!(opts, println!("Running {} v{}", crate_name!(), crate_version!()));
 
 	match opts.subcmd {
@@ -57,13 +61,43 @@ fn main() -> color_eyre::Result<()> {
 			info!("⏱️  Loading WASM from {:?}", &source);
 			let subwasm = Subwasm::new(&source);
 
-			if let Some(filter) = meta_opts.module {
-				subwasm.display_module(filter);
-			} else if opts.json {
-				subwasm.display_metadata_json()
-			} else {
-				subwasm.display_modules_list()
+			let mut fmt: OutputFormat = meta_opts.format.unwrap_or_else(|| "human".into()).into();
+			if opts.json {
+				eprintln!("--json is DEPRECATED, use --format=json instead");
+				fmt = OutputFormat::Json;
 			}
+
+			let mut output = meta_opts.output;
+			if let Some(out) = &output {
+				if out.is_empty() || out == "auto" {
+					match fmt {
+						OutputFormat::Human => output = Some("metadata.txt".into()),
+						OutputFormat::Json => output = Some("metadata.json".into()),
+						OutputFormat::Scale => output = Some("metadata.scale".into()),
+						OutputFormat::HexScale => output = Some("metadata.hex".into()),
+						OutputFormat::JsonScale => output = Some("metadata.jscale".into()),
+					}
+				}
+			}
+
+			let mut out: Box<dyn Write> = if let Some(output) = &output {
+				Box::new(std::fs::File::create(output)?)
+			} else {
+				Box::new(std::io::stdout())
+			};
+
+			match subwasm.write_metadata(fmt, meta_opts.module, &mut out) {
+				Ok(_) => Ok(()),
+				Err(e) => {
+					if let Some(e) = e.root_cause().downcast_ref::<std::io::Error>() {
+						if e.kind() == std::io::ErrorKind::BrokenPipe {
+							log::debug!("ignoring broken pipe error: {:?}", e);
+							return Ok(());
+						}
+					}
+					Err(e)
+				}
+			}?
 		}
 
 		SubCommand::Diff(diff_opts) => {
@@ -77,11 +111,11 @@ fn main() -> color_eyre::Result<()> {
 		}
 
 		SubCommand::Compress(copts) => {
-			compress(copts.input, copts.output).unwrap();
+			compress(copts.input, copts.output)?;
 		}
 
 		SubCommand::Decompress(dopts) => {
-			decompress(dopts.input, dopts.output).unwrap();
+			decompress(dopts.input, dopts.output)?;
 		}
 	};
 

cli/src/opts.rs

@@ -132,6 +132,15 @@ pub struct MetaOpts {
 	/// Currently, you must pass a block hash. Passing the block numbers is not supported.
 	#[clap(short, long)]
 	pub block: Option<String>, // TODO: can do better...
+
+	/// You may specifiy the output format. One of "human", "scale", "json", "json+scale", "hex+scale"
+	#[clap(long, short, default_value = "human")]
+	pub format: Option<String>,
+
+	/// You may specifiy the output filename where the metadata will be saved.
+	/// Alternatively, you may use `auto` and an appropriate name will be generated according to the `format` your chose.
+	#[clap(short, long)]
+	pub output: Option<String>,
 }
 
 /// Compare 2 runtimes

cli/tests/test.rs

@@ -32,7 +32,7 @@ mod cli_tests {
 		fn it_gets_a_runtime() {
 			let mut cmd = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
 
-			let assert = cmd.args(&["get", "--output", "runtime.wasm", "wss://rpc.polkadot.io:443"]).assert();
+			let assert = cmd.args(["get", "--output", "runtime.wasm", "wss://rpc.polkadot.io:443"]).assert();
 			assert.success().code(0);
 			assert!(Path::new("runtime.wasm").exists());
 		}
@@ -41,7 +41,7 @@ mod cli_tests {
 		fn it_fails_on_bad_chain() {
 			let mut cmd = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
 
-			let assert = cmd.args(&["get", "--chain", "foobar"]).assert();
+			let assert = cmd.args(["get", "--chain", "foobar"]).assert();
 			assert.failure().code(101);
 		}
 	}
@@ -53,11 +53,11 @@ mod cli_tests {
 		#[test]
 		fn it_shows_metadata() {
 			let mut cmd = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
-			let assert = cmd.args(&["get", "wss://rpc.polkadot.io:443", "--output", "runtime.wasm"]).assert();
+			let assert = cmd.args(["get", "wss://rpc.polkadot.io:443", "--output", "runtime.wasm"]).assert();
 			assert.success().code(0);
 
 			let mut cmd = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
-			let assert = cmd.args(&["meta", "runtime.wasm"]).assert();
+			let assert = cmd.args(["meta", "runtime.wasm"]).assert();
 			assert.success().code(0);
 		}
 	}
@@ -69,27 +69,27 @@ mod cli_tests {
 		#[test]
 		fn it_does_basic_compress_decompress() {
 			let mut cmd = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
-			let assert = cmd.args(&["get", "wss://rpc.polkadot.io:443", "--output", "compressed.wasm"]).assert();
+			let assert = cmd.args(["get", "wss://rpc.polkadot.io:443", "--output", "compressed.wasm"]).assert();
 			assert.success().code(0);
 
 			let mut cmd = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
-			cmd.args(&["decompress", "compressed.wasm", "decompressed.wasm"]).assert().success().code(0);
+			cmd.args(["decompress", "compressed.wasm", "decompressed.wasm"]).assert().success().code(0);
 
 			let mut cmd = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
-			cmd.args(&["compress", "decompressed.wasm", "new_compressed.wasm"]).assert().success().code(0);
+			cmd.args(["compress", "decompressed.wasm", "new_compressed.wasm"]).assert().success().code(0);
 		}
 
 		#[test]
 		fn it_does_decompress_on_already() {
 			let mut cmd = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
-			let assert = cmd.args(&["get", "wss://rpc.polkadot.io:443", "--output", "compressed.wasm"]).assert();
+			let assert = cmd.args(["get", "wss://rpc.polkadot.io:443", "--output", "compressed.wasm"]).assert();
 			assert.success().code(0);
 
 			let mut cmd = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
-			cmd.args(&["decompress", "compressed.wasm", "decompressed.wasm"]).assert().success().code(0);
+			cmd.args(["decompress", "compressed.wasm", "decompressed.wasm"]).assert().success().code(0);
 
 			let mut cmd = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
-			cmd.args(&["decompress", "decompressed.wasm", "new_decompressed.wasm"]).assert().success().code(0);
+			cmd.args(["decompress", "decompressed.wasm", "new_decompressed.wasm"]).assert().success().code(0);
 		}
 	}
 }

doc/usage_meta.adoc

@@ -10,5 +10,7 @@ Options:
   -j, --json             Output as json
   -m, --module <MODULE>  Without this flag, the metadata command display the list of all modules. Using this flag, you will only see the module of your choice and a few details about it
   -b, --block <BLOCK>    The optional block where to fetch the runtime. That allows fetching older runtimes but you will need to connect to archive nodes. Currently, you must pass a block hash. Passing the block numbers is not supported
+  -f, --format <FORMAT>  You may specifiy the output format. One of "human", "scale", "json", "json+scale", "hex+scale" [default: human]
+  -o, --output <OUTPUT>  You may specifiy the output filename where the metadata will be saved. Alternatively, you may use `auto` and an appropriate name will be generated according to the `format` your chose
   -h, --help             Print help information
   -V, --version          Print version information

lib/Cargo.toml

@@ -18,7 +18,6 @@ repository = "https://github.com/chevdor/subwasm"
 version = "0.18.0"
 
 [dependencies]
-calm_io = "0.1"
 color-eyre = "0.6"
 frame-metadata = { version = "15", package = "frame-metadata", features = [
     "v12",
@@ -39,3 +38,4 @@ substrate-differ = { version = "0.18.0", path = "../libs/substrate-differ" }
 wasm-loader = { version = "0.18.0", path = "../libs/wasm-loader" }
 wasm-testbed = { version = "0.18.0", path = "../libs/wasm-testbed" }
 sp-version = { tag = "monthly-2023-01", git = "https://github.com/paritytech/substrate" }
+hex = "0.4"

lib/src/lib.rs

@@ -1,3 +1,4 @@
+use color_eyre::eyre::eyre;
 use std::path::Path;
 use std::{fs::File, path::PathBuf};
 use std::{io::prelude::*, str::FromStr};
@@ -17,6 +18,7 @@ mod subwasm;
 mod types;
 pub use chain_info::*;
 use log::{debug, info};
+pub use metadata_wrapper::OutputFormat;
 pub use runtime_info::*;
 pub use subwasm::*;
 pub use types::*;
@@ -67,7 +69,7 @@ pub fn download_runtime(url: &str, block_ref: Option<BlockRef>, output: Option<P
 	let url = match url {
 		url if url.starts_with("ws") => NodeEndpoint::WebSocket(url.to_string()),
 		url if url.starts_with("http") => NodeEndpoint::Http(url.to_string()),
-		_ => panic!("The url should either start with http or ws"),
+		_ => return Err(eyre!("The url should either start with http or ws")),
 	};
 
 	let reference = OnchainBlock { endpoint: url, block_ref };
@@ -129,41 +131,41 @@ pub fn diff(src_a: Source, src_b: Source) {
 
 /// Compress a given runtime into a new file. You cannot compress
 /// a runtime that is already compressed.
-pub fn compress(input: PathBuf, output: PathBuf) -> Result<(), String> {
-	let wasm = WasmLoader::load_from_source(&Source::File(input)).unwrap();
+pub fn compress(input: PathBuf, output: PathBuf) -> color_eyre::Result<()> {
+	let wasm = WasmLoader::load_from_source(&Source::File(input))?;
 
 	if wasm.compression().compressed() {
-		return Err("The input is already compressed".into());
+		return Err(eyre!("The input is already compressed"));
 	}
 
-	let bytes_compressed = Compression::compress(wasm.original_bytes()).unwrap();
+	let bytes_compressed = Compression::compress(wasm.original_bytes()).map_err(|e| eyre!(e))?;
 
 	debug!("original   = {:?}", wasm.original_bytes().len());
 	debug!("compressed = {:?}", bytes_compressed.len());
 	info!("Saving compressed runtime to {:?}", output);
 
-	let mut buffer = File::create(output).unwrap();
-	buffer.write_all(&bytes_compressed.to_vec()).unwrap();
+	let mut buffer = File::create(output)?;
+	buffer.write_all(&bytes_compressed.to_vec())?;
 
 	Ok(())
 }
 
 /// Decompress a given runtime file. It is fine decompressing an already
 /// decompressed runtime, you will just get the same.
-pub fn decompress(input: PathBuf, output: PathBuf) -> Result<(), String> {
-	let wasm = WasmLoader::load_from_source(&Source::File(input)).unwrap();
+pub fn decompress(input: PathBuf, output: PathBuf) -> color_eyre::Result<()> {
+	let wasm = WasmLoader::load_from_source(&Source::File(input))?;
 
 	let bytes_decompressed = match wasm.compression().compressed() {
 		false => wasm.original_bytes().clone(),
-		true => Compression::decompress(wasm.original_bytes()).unwrap(),
+		true => Compression::decompress(wasm.original_bytes()).map_err(|e| eyre!(e))?,
 	};
 
 	debug!("original     = {:?}", wasm.original_bytes().len());
 	debug!("decompressed = {:?}", bytes_decompressed.len());
 
 	info!("Saving decompressed runtime to {:?}", output);
-	let mut buffer = File::create(output).unwrap();
-	buffer.write_all(&bytes_decompressed.to_vec()).unwrap();
+	let mut buffer = File::create(output)?;
+	buffer.write_all(&bytes_decompressed.to_vec())?;
 
 	Ok(())
 }