fix(clippy): split code a bit

Main was too big for clippy

src/main.rs

@@ -128,7 +128,7 @@ impl SavedIPs {
             .chain(self.ipv6.map(IpAddr::V6))
     }
 
-    fn from_str(data: &str) -> miette::Result<Self> {
+    fn from_str(data: &str) -> Result<Self> {
         match data.parse::<IpAddr>() {
             // Old format
             Ok(IpAddr::V4(ipv4)) => Ok(Self {
@@ -145,7 +145,7 @@ impl SavedIPs {
 }
 
 impl AppState<'static> {
-    fn from_args(args: &Opts, config: &config::Config) -> miette::Result<Self> {
+    fn from_args(args: &Opts, config: &config::Config) -> Result<Self> {
         let Opts {
             verbosity: _,
             data_dir,
@@ -180,7 +180,7 @@ impl AppState<'static> {
             // Load keyfile
             key_file: key_file
                 .as_deref()
-                .map(|path| -> miette::Result<_> {
+                .map(|path| -> Result<_> {
                     std::fs::File::open(path)
                         .into_diagnostic()
                         .wrap_err_with(|| {
@@ -255,6 +255,18 @@ impl std::str::FromStr for Ipv6Prefix {
     }
 }
 
+fn load_password(path: &Path) -> Result<Box<[u8]>> {
+    let pass = std::fs::read_to_string(path).into_diagnostic()?;
+
+    let pass: Box<[u8]> = URL_SAFE_NO_PAD
+        .decode(pass.trim().as_bytes())
+        .into_diagnostic()
+        .wrap_err_with(|| format!("failed to decode password from {}", path.display()))?
+        .into();
+
+    Ok(pass)
+}
+
 #[tracing::instrument(err)]
 fn main() -> Result<()> {
     // set panic hook to pretty print with miette's formatter
@@ -310,18 +322,8 @@ fn main() -> Result<()> {
     let password_hash = config
         .password
         .password_file
-        .map(|path| -> miette::Result<_> {
-            let path = path.as_path();
-            let pass = std::fs::read_to_string(path).into_diagnostic()?;
-
-            let pass: Box<[u8]> = URL_SAFE_NO_PAD
-                .decode(pass.trim().as_bytes())
-                .into_diagnostic()
-                .wrap_err_with(|| format!("failed to decode password from {}", path.display()))?
-                .into();
-
-            Ok(pass)
-        })
+        .as_deref()
+        .map(load_password)
         .transpose()
         .wrap_err("failed to load password hash")?;
 
@@ -336,7 +338,16 @@ fn main() -> Result<()> {
         .into_diagnostic()
         .wrap_err("failed to start the tokio runtime")?;
 
-    rt.block_on(async {
+    rt.block_on(async_main(state, config, password_hash))
+        .wrap_err("failed to run main loop")
+}
+
+#[tracing::instrument(err, skip(state, pass))]
+async fn async_main(
+    state: AppState<'static>,
+    config: Config,
+    pass: Option<Box<[u8]>>,
+) -> Result<()> {
     // Update DNS record with previous IPs (if available)
     let ips = state.last_ips.lock().await.clone();
 
@@ -366,7 +377,7 @@ fn main() -> Result<()> {
     // Create services
     let app = Router::new().route("/update", get(update_records));
     // if a password is provided, validate it
-        let app = if let Some(pass) = password_hash {
+    let app = if let Some(pass) = pass {
         app.layer(auth::layer(
             Box::leak(pass),
             Box::leak(config.password.salt),
@@ -391,8 +402,6 @@ fn main() -> Result<()> {
     )
     .await
     .into_diagnostic()
-    })
-    .wrap_err("failed to run main loop")
 }
 
 /// Serde deserialization decorator to map empty Strings to None,