feat: add ChainspecParser trait (#9259)

Co-authored-by: Matthias Seitz <matthias.seitz@outlook.de>

crates/cli/cli/Cargo.toml

@@ -13,6 +13,8 @@ repository.workspace = true
 [dependencies]
 # reth
 reth-cli-runner.workspace = true
+reth-chainspec.workspace = true
+eyre.workspace = true
 
 # misc
 clap.workspace = true

crates/cli/cli/src/chainspec.rs

@@ -0,0 +1,25 @@
+use clap::builder::TypedValueParser;
+use reth_chainspec::ChainSpec;
+use std::sync::Arc;
+
+/// Trait for parsing chain specifications.
+///
+/// This trait extends [`clap::builder::TypedValueParser`] to provide a parser for chain
+/// specifications. Implementers of this trait must provide a list of supported chains and a
+/// function to parse a given string into a [`ChainSpec`].
+pub trait ChainSpecParser: TypedValueParser<Value = Arc<ChainSpec>> + Default {
+    /// List of supported chains.
+    const SUPPORTED_CHAINS: &'static [&'static str];
+
+    /// Parses the given string into a [`ChainSpec`].
+    ///
+    /// # Arguments
+    ///
+    /// * `s` - A string slice that holds the chain spec to be parsed.
+    ///
+    /// # Errors
+    ///
+    /// This function will return an error if the input string cannot be parsed into a valid
+    /// [`ChainSpec`].
+    fn parse(&self, s: &str) -> eyre::Result<Arc<ChainSpec>>;
+}

crates/cli/cli/src/lib.rs

@@ -14,6 +14,8 @@ use reth_cli_runner::CliRunner;
 
 use clap::{Error, Parser};
 
+pub mod chainspec;
+
 /// Reth based node cli.
 ///
 /// This trait is supposed to be implemented by the main struct of the CLI.