Add value delimiter and tests args (#2280)

## Description
This PR adds the possibility to define multiple relayers with ','
delimiter in args. It also adds a test for the relayer argument.

## Checklist
- [x] Breaking changes are clearly marked as such in the PR description
and changelog
- [x] New behavior is reflected in tests
- [x] [The specification](https://github.com/FuelLabs/fuel-specs/)
matches the implemented behavior (link update PR if changes are needed)

### Before requesting review
- [x] I have reviewed the code myself
- [x] I have created follow-up issues caused by this PR and linked them
here

CHANGELOG.md

@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - [2189](https://github.com/FuelLabs/fuel-core/pull/2151): Select next DA height to never include more than u16::MAX -1 transactions from L1.
 - [2162](https://github.com/FuelLabs/fuel-core/pull/2162): Pool structure with dependencies, etc.. for the next transaction pool module. Also adds insertion/verification process in PoolV2 and tests refactoring
 - [2265](https://github.com/FuelLabs/fuel-core/pull/2265): Integrate Block Committer API for DA Block Costs.
+- [2280](https://github.com/FuelLabs/fuel-core/pull/2280): Allow comma separated relayer addresses in cli
 
 ### Changed
 

bin/fuel-core/src/cli/run/relayer.rs

@@ -19,7 +19,7 @@ pub struct RelayerArgs {
 
     /// Uri addresses to ethereum client. It can be in format of `http://localhost:8545/` or `ws://localhost:8545/`.
     /// If not set relayer will not start.
-    #[arg(long = "relayer", env)]
+    #[arg(long = "relayer", value_delimiter = ',', env)]
     #[arg(required_if_eq("enable_relayer", "true"))]
     #[arg(requires_if(IsPresent, "enable_relayer"))]
     pub relayer: Option<Vec<url::Url>>,
@@ -70,3 +70,27 @@ impl RelayerArgs {
         Some(config)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use clap::Parser;
+    use test_case::test_case;
+
+    #[derive(Debug, Clone, Parser)]
+    pub struct Command {
+        #[clap(flatten)]
+        relayer: RelayerArgs,
+    }
+
+    #[test_case(&[""] => Ok(None); "no args")]
+    #[test_case(&["", "--enable-relayer", "--relayer=https://test.com"] => Ok(Some(vec![url::Url::parse("https://test.com").unwrap()])); "one relayer")]
+    #[test_case(&["", "--enable-relayer", "--relayer=https://test.com", "--relayer=https://test2.com"] => Ok(Some(vec![url::Url::parse("https://test.com").unwrap(), url::Url::parse("https://test2.com").unwrap()])); "two relayers in different args")]
+    #[test_case(&["", "--enable-relayer", "--relayer=https://test.com,https://test2.com"] => Ok(Some(vec![url::Url::parse("https://test.com").unwrap(), url::Url::parse("https://test2.com").unwrap()])); "two relayers in same arg")]
+    fn parse_relayer_urls(args: &[&str]) -> Result<Option<Vec<url::Url>>, String> {
+        let command: Command =
+            Command::try_parse_from(args).map_err(|e| e.to_string())?;
+        let args = command.relayer;
+        Ok(args.relayer)
+    }
+}