move multipart error handling into its module

src/multipart.rs

@@ -5,10 +5,14 @@ use futures_util::{StreamExt, TryStreamExt};
 use mime::{Mime, APPLICATION_OCTET_STREAM, TEXT_PLAIN};
 use std::{
     cmp::{max, min},
+    io::ErrorKind,
     path::Path,
 };
 use time::{Duration, OffsetDateTime};
-use tokio::{fs::File, io::AsyncWriteExt};
+use tokio::{
+    fs::{self, File},
+    io::AsyncWriteExt,
+};
 
 const MAX_UPLOAD_DURATION: Duration = Duration::days(31);
 const DEFAULT_UPLOAD_DURATION: Duration = Duration::minutes(30);
@@ -21,6 +25,25 @@ pub(crate) struct UploadConfig {
 }
 
 pub(crate) async fn parse_multipart(
+    payload: Multipart,
+    file_path: &Path,
+    config: &config::Config,
+) -> Result<UploadConfig, error::Error> {
+    match parse_multipart_inner(payload, file_path, config).await {
+        Ok(data) => Ok(data),
+        Err(err) => {
+            match fs::remove_file(file_path).await {
+                Err(err) if err.kind() != ErrorKind::NotFound => {
+                    log::error!("could not remove file {:?}", err);
+                }
+                _ => {}
+            }
+            Err(err)
+        }
+    }
+}
+
+pub(crate) async fn parse_multipart_inner(
     mut payload: Multipart,
     file_path: &Path,
     config: &config::Config,

src/upload.rs

@@ -41,28 +41,12 @@ pub async fn upload(
         error::ErrorInternalServerError("could not create file")
     })?;
 
-    let parsed_multipart = multipart::parse_multipart(payload, &file_name, &config).await;
     let UploadConfig {
         original_name,
         content_type,
         valid_till,
         delete_on_download,
-    } = match parsed_multipart {
+    } = multipart::parse_multipart(payload, &file_name, &config).await?;
-        Ok(data) => data,
-        Err(err) => {
-            match fs::remove_file(file_name).await {
-                Ok(()) => {}
-                Err(err) if err.kind() == ErrorKind::NotFound => {}
-                Err(err) => {
-                    log::error!("could not remove file {:?}", err);
-                    return Err(error::ErrorInternalServerError(
-                        "could not parse multipart; could not remove file",
-                    ));
-                }
-            }
-            return Err(err);
-        }
-    };
 
     let file_name = original_name.clone().unwrap_or_else(|| {
         format!(