feat(rust): implemented the config argument

rust/src/main.rs

@@ -1,3 +1,5 @@
+use std::path::Path;
+
 use clap::Parser;
 use figment::{
     Figment,
@@ -6,22 +8,37 @@ use figment::{
 use tracing::{Level, event};
 
 mod args;
-use args::{ActionType, CommandArgs};
+use crate::args::{ActionType, ArgsError, CommandArgs};
 
 mod config;
 
 mod error;
-use error::CommandError;
+use crate::error::CommandError;
 
 #[tokio::main]
 async fn main() -> Result<(), CommandError> {
     let args = CommandArgs::parse();
 
-    let config: config::CommandConfig = Figment::new()
+    let figment = Figment::new()
         .admerge(Json::file("config.json"))
-        .admerge(Toml::file("config.toml"))
-        .admerge(Env::prefixed("APP_"))
-        .extract()?;
+        .admerge(Toml::file("config.toml"));
+
+    let config: config::CommandConfig = match &args.config {
+        None => figment,
+        Some(f) => {
+            let file = Path::new(&f);
+
+            match file.extension().and_then(|e| e.to_str()) {
+                Some("toml") => Ok(figment.admerge(Toml::file(file))),
+                Some("json") => Ok(figment.admerge(Json::file(file))),
+                _ => Err(ArgsError::InvalidConfigExtension(
+                    file.extension().and_then(|e| e.to_str().map(String::from)),
+                )),
+            }
+        }?,
+    }
+    .admerge(Env::prefixed("APP_"))
+    .extract()?;
 
     match &args.action {
         ActionType::Serve(serve_args) => {
@@ -41,7 +58,9 @@ async fn main() -> Result<(), CommandError> {
 
             println!("{:#?}", config.port.ports);
         }
-    }
+    };
+
+    println!("{}", CommandError::InvalidArgument(ArgsError::InvalidConfigExtension(Some(String::from("txt")))));
 
     Ok(())
 }