Metadata: Retain a subset of metadata pallets

cli/src/commands/codegen.rs

@@ -3,11 +3,9 @@
 // see LICENSE for license details.
 
 use clap::Parser as ClapParser;
-use jsonrpsee::client_transport::ws::Uri;
-use std::path::PathBuf;
 use subxt_codegen::{DerivesRegistry, TypeSubstitutes};
 
-use super::utils::MetadataSource;
+use super::utils::FileOrUrl;
 
 /// Generate runtime API client code from metadata.
 ///
@@ -16,12 +14,8 @@ use super::utils::MetadataSource;
 /// `subxt codegen | rustfmt --edition=2018 --emit=stdout`
 #[derive(Debug, ClapParser)]
 pub struct Opts {
-    /// The url of the substrate node to query for metadata for codegen.
-    #[clap(name = "url", long, value_parser)]
-    url: Option<Uri>,
-    /// The path to the encoded metadata file.
-    #[clap(short, long, value_parser)]
-    file: Option<PathBuf>,
+    #[command(flatten)]
+    file_or_url: FileOrUrl,
     /// Additional derives
     #[clap(long = "derive")]
     derives: Vec<String>,
@@ -53,8 +47,7 @@ fn derive_for_type_parser(src: &str) -> Result<(String, String), String> {
 }
 
 pub async fn run(opts: Opts) -> color_eyre::Result<()> {
-    let source = MetadataSource::new(opts.url, opts.file)?;
-    let bytes = source.fetch().await?;
+    let bytes = opts.file_or_url.fetch().await?;
 
     codegen(
         &bytes,

cli/src/commands/metadata.rs

@@ -5,25 +5,17 @@
 use clap::Parser as ClapParser;
 use color_eyre::eyre;
 use frame_metadata::{RuntimeMetadata, RuntimeMetadataPrefixed};
-use jsonrpsee::client_transport::ws::Uri;
 use scale::{Decode, Encode};
-use std::{
-    io::{self, Write},
-    path::PathBuf,
-};
+use std::io::{self, Write};
 use subxt_metadata::retain_metadata_pallets;
 
-use super::utils::MetadataSource;
+use super::utils::FileOrUrl;
 
 /// Download metadata from a substrate node, for use with `subxt` codegen.
 #[derive(Debug, ClapParser)]
 pub struct Opts {
-    /// The url of the substrate node to query for metadata for codegen.
-    #[clap(name = "url", long, value_parser)]
-    url: Option<Uri>,
-    /// The path to the encoded metadata file.
-    #[clap(short, long, value_parser)]
-    file: Option<PathBuf>,
+    #[command(flatten)]
+    file_or_url: FileOrUrl,
     /// The format of the metadata to display: `json`, `hex` or `bytes`.
     #[clap(long, short, default_value = "bytes")]
     format: String,
@@ -34,8 +26,7 @@ pub struct Opts {
 }
 
 pub async fn run(opts: Opts) -> color_eyre::Result<()> {
-    let source = MetadataSource::new(opts.url, opts.file)?;
-    let bytes = source.fetch().await?;
+    let bytes = opts.file_or_url.fetch().await?;
     let mut metadata = <RuntimeMetadataPrefixed as Decode>::decode(&mut &bytes[..])?;
 
     if let Some(pallets) = opts.pallets {

cli/src/commands/utils.rs

@@ -2,47 +2,42 @@
 // This file is dual-licensed as Apache-2.0 or GPL-3.0.
 // see LICENSE for license details.
 
+use clap::Args;
 use std::{fs, io::Read, path::PathBuf};
 
 use color_eyre::eyre;
 use subxt_codegen::utils::Uri;
 
-// The source of the metadata.
-pub enum MetadataSource {
-    // Metadata is loaded from a file.
-    FilePath(PathBuf),
-    // Metadata is downloaded from a runtime node.
-    Uri(Uri),
+/// The source of the metadata.
+#[derive(Debug, Args)]
+pub struct FileOrUrl {
+    /// The url of the substrate node to query for metadata for codegen.
+    #[clap(name = "url", long, value_parser)]
+    url: Option<Uri>,
+    /// The path to the encoded metadata file.
+    #[clap(short, long, value_parser)]
+    file: Option<PathBuf>,
 }
 
-impl MetadataSource {
-    /// Constructs a new [`MetadataSource`].
-    pub fn new(url: Option<Uri>, file: Option<PathBuf>) -> color_eyre::Result<Self> {
-        if let Some(file) = file {
-            if url.is_some() {
+impl FileOrUrl {
+    /// Fetch the metadata bytes.
+    pub async fn fetch(&self) -> color_eyre::Result<Vec<u8>> {
+        if let Some(path) = &self.file {
+            if self.url.is_some() {
                 eyre::bail!("specify one of `--url` or `--file` but not both")
             };
 
-            return Ok(Self::FilePath(file));
+            let mut file = fs::File::open(path)?;
+            let mut bytes = Vec::new();
+            file.read_to_end(&mut bytes)?;
+            return Ok(bytes);
         }
-        let url = url.unwrap_or_else(|| {
+
+        let url = self.url.clone().unwrap_or_else(|| {
             "http://localhost:9933"
                 .parse::<Uri>()
                 .expect("default url is valid")
         });
-        Ok(Self::Uri(url))
-    }
-
-    /// Fetch the metadata bytes.
-    pub async fn fetch(&self) -> color_eyre::Result<Vec<u8>> {
-        match &self {
-            Self::FilePath(path) => {
-                let mut file = fs::File::open(path)?;
-                let mut bytes = Vec::new();
-                file.read_to_end(&mut bytes)?;
-                Ok(bytes)
-            }
-            Self::Uri(url) => Ok(subxt_codegen::utils::fetch_metadata_bytes(url).await?),
-        }
+        Ok(subxt_codegen::utils::fetch_metadata_bytes(&url).await?)
     }
 }