avatar: return 404 if user does not exist

crates/ezidam/src/error.rs

@@ -39,4 +39,8 @@ impl Error {
     pub fn internal_server_error<E: std::error::Error>(error: E) -> Self {
         Self::new(Status::InternalServerError, error)
     }
+
+    pub fn not_found<M: std::fmt::Display>(value: M) -> Self {
+        Self::new(Status::NotFound, value)
+    }
 }

crates/ezidam/src/routes/root.rs

@@ -47,7 +47,9 @@ async fn avatar(
     size: Option<u32>,
 ) -> Result<FileFromBytes> {
     // Verify existence of user
-    let _user = User::get_by_id(&mut *db, &user_id.0).await?;
+    let _user = User::get_by_id(&mut *db, &user_id.0)
+        .await?
+        .ok_or_else(|| Error::not_found(user_id.0.to_string()))?;
 
     // Generate avatar
     let avatar = task::spawn_blocking(move || {