improve error handling

src/main.rs

@@ -36,7 +36,7 @@ async fn index() -> Result<NamedFile, Error> {
 async fn upload(
     payload: Multipart,
     db: web::Data<PgPool>,
-    sender: web::Data<Sender<()>>,
+    expiry_watch_sender: web::Data<Sender<()>>,
     config: web::Data<Config>,
 ) -> Result<HttpResponse, Error> {
     let file_id = format!("{:x?}", rand::random::<u32>());
@@ -48,22 +48,35 @@ async fn upload(
             Ok(data) => data,
             Err(err) => {
                 if filename.exists().await {
-                    fs::remove_file(filename)
-                        .await
-                        .map_err(|_| error::ErrorInternalServerError("could not remove file"))?;
+                    fs::remove_file(filename).await.map_err(|_| {
+                        error::ErrorInternalServerError(
+                            "could not parse multipart; could not remove file",
+                        )
+                    })?;
                 }
                 return Err(err);
             }
         };
 
-    sqlx::query("INSERT INTO Files (file_id, file_name, valid_till, kind) VALUES ($1, $2, $3, $4)")
-        .bind(&file_id)
-        .bind(original_name.as_ref().unwrap_or_else(|| &file_id))
-        .bind(valid_till.naive_local())
-        .bind(kind.to_string())
-        .execute(db.as_ref())
-        .await
-        .map_err(|_| error::ErrorInternalServerError("could not insert file into database"))?;
+    let db_insert = sqlx::query(
+        "INSERT INTO Files (file_id, file_name, valid_till, kind) VALUES ($1, $2, $3, $4)",
+    )
+    .bind(&file_id)
+    .bind(original_name.as_ref().unwrap_or(&file_id))
+    .bind(valid_till.naive_local())
+    .bind(kind.to_string())
+    .execute(db.as_ref())
+    .await;
+    if db_insert.is_err() {
+        fs::remove_file(filename).await.map_err(|_| {
+            error::ErrorInternalServerError(
+                "could not insert file into database; could not remove file",
+            )
+        })?;
+        return Err(error::ErrorInternalServerError(
+            "could not insert file into database",
+        ));
+    }
 
     log::info!(
         "create new file {} (valid_till: {}, kind: {})",
@@ -72,7 +85,7 @@ async fn upload(
         kind
     );
 
-    sender.send(()).await;
+    expiry_watch_sender.send(()).await;
 
     let redirect = if kind == FileKind::BINARY && original_name.is_some() {
         format!("/upload/{}/{}", file_id, original_name.unwrap())
@@ -219,7 +232,7 @@ async fn main() -> std::io::Result<()> {
     ));
 
     let db = web::Data::new(pool);
-    let sender = web::Data::new(sender);
+    let expiry_watch_sender = web::Data::new(sender);
     let upload_max_bytes: usize = env::var("UPLOAD_MAX_BYTES")
         .ok()
         .and_then(|variable| variable.parse().ok())
@@ -231,7 +244,7 @@ async fn main() -> std::io::Result<()> {
             App::new()
                 .wrap(middleware::Logger::default())
                 .app_data(db.clone())
-                .app_data(sender.clone())
+                .app_data(expiry_watch_sender.clone())
                 .app_data(Bytes::configure(|cfg| cfg.limit(upload_max_bytes)))
                 .data(config.clone())
                 .service(web::resource("/").route(web::get().to(index)))

src/multipart.rs

@@ -79,10 +79,10 @@ pub(crate) async fn parse_multipart(
 fn get_field_name(field: &Field) -> Result<String, error::Error> {
     Ok(field
         .content_disposition()
-        .ok_or_else(|| error::ParseError::Incomplete)?
+        .ok_or(error::ParseError::Incomplete)?
         .get_name()
         .map(|s| s.to_owned())
-        .ok_or_else(|| error::ParseError::Incomplete)?)
+        .ok_or(error::ParseError::Incomplete)?)
 }
 
 async fn parse_string(name: &str, field: actix_multipart::Field) -> Result<String, error::Error> {