Impl OptionalFromRequest on MultipartFile and change behaviour on MultipartFiles to contain 0 files

Cargo.toml

@@ -4,7 +4,7 @@ exclude = ["examples"]
 
 [workspace.package]
 edition = "2024"
-rust-version = "1.88"
+rust-version = "1.89"
 authors = ["Martin Berg Alstad"]
 homepage = "martials.no"
 
@@ -60,7 +60,7 @@ derive_more = { workspace = true, features = ["from", "constructor"] }
 tokio = "1.40"
 # Database
 diesel = "2.2"
-diesel-async = "0.5"
+diesel-async = "0.6"
 diesel_migrations = "2.2"
 deadpool-diesel = "0.6"
 # Error handling
@@ -71,13 +71,13 @@ quote = "1.0"
 deluxe = "0.5"
 proc-macro2 = "1.0"
 # Test
-testcontainers-modules = "0.11"
+testcontainers-modules = "0.13"
 # Utils
 derive_more = "2.0"
 regex = "1.11"
 
 [features]
-axum = ["dep:axum", "dep:tower", "dep:tower-http", "dep:thiserror", "dep:tracing", "dep:tracing-subscriber", "dep:tokio", "dep:mime"]
+axum = ["dep:axum", "dep:tower", "dep:serde", "dep:tower-http", "dep:thiserror", "dep:tracing", "dep:tracing-subscriber", "dep:tokio", "dep:mime"]
 diesel = ["dep:diesel-crud-trait", "dep:diesel", "dep:diesel-async", "dep:deadpool-diesel", "dep:diesel_migrations"]
 io = ["dep:tokio", "dep:tokio-util"]
 iter = []

examples/multipart_file/Cargo.lock

@@ -17,58 +17,13 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
 
-[[package]]
-name = "async-trait"
-version = "0.1.80"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c6fa2087f2753a7da8cc1c0dbfcf89579dd57458e36769de5ac750b4671737ca"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
-
-[[package]]
-name = "axum"
-version = "0.7.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3a6c9af12842a67734c9a2e355436e5d03b22383ed60cf13cd0c18fbfe3dcbcf"
-dependencies = [
- "async-trait",
- "axum-core 0.4.3",
- "bytes",
- "futures-util",
- "http",
- "http-body",
- "http-body-util",
- "hyper",
- "hyper-util",
- "itoa",
- "matchit 0.7.3",
- "memchr",
- "mime",
- "percent-encoding",
- "pin-project-lite",
- "rustversion",
- "serde",
- "serde_json",
- "serde_path_to_error",
- "serde_urlencoded",
- "sync_wrapper 1.0.1",
- "tokio",
- "tower 0.4.13",
- "tower-layer",
- "tower-service",
- "tracing",
-]
-
 [[package]]
 name = "axum"
 version = "0.8.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "021e862c184ae977658b36c4500f7feac3221ca5da43e3f25bd04ab6c79a29b5"
 dependencies = [
- "axum-core 0.5.2",
+ "axum-core",
  "bytes",
  "form_urlencoded",
  "futures-util",
@@ -78,7 +33,7 @@ dependencies = [
  "hyper",
  "hyper-util",
  "itoa",
- "matchit 0.8.4",
+ "matchit",
  "memchr",
  "mime",
  "multer",
@@ -89,7 +44,7 @@ dependencies = [
  "serde_json",
  "serde_path_to_error",
  "serde_urlencoded",
- "sync_wrapper 1.0.1",
+ "sync_wrapper",
  "tokio",
  "tower 0.5.2",
  "tower-layer",
@@ -97,27 +52,6 @@ dependencies = [
  "tracing",
 ]
 
-[[package]]
-name = "axum-core"
-version = "0.4.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a15c63fd72d41492dc4f497196f5da1fb04fb7529e631d73630d1b491e47a2e3"
-dependencies = [
- "async-trait",
- "bytes",
- "futures-util",
- "http",
- "http-body",
- "http-body-util",
- "mime",
- "pin-project-lite",
- "rustversion",
- "sync_wrapper 0.1.2",
- "tower-layer",
- "tower-service",
- "tracing",
-]
-
 [[package]]
 name = "axum-core"
 version = "0.5.2"
@@ -132,7 +66,7 @@ dependencies = [
  "mime",
  "pin-project-lite",
  "rustversion",
- "sync_wrapper 1.0.1",
+ "sync_wrapper",
  "tower-layer",
  "tower-service",
  "tracing",
@@ -375,9 +309,10 @@ checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
 name = "lib"
 version = "2.0.0"
 dependencies = [
- "axum 0.8.4",
+ "axum",
  "derive_more",
  "mime",
+ "serde",
  "thiserror",
  "tokio",
  "tower 0.5.2",
@@ -398,12 +333,6 @@ version = "0.4.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a7a70ba024b9dc04c27ea2f0c0548feb474ec5c54bba33a7f72f873a39d07b24"
 
-[[package]]
-name = "matchit"
-version = "0.7.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0e7465ac9959cc2b1404e8e2367b43684a6d13790fe23056cc8c6c5a6b7bcb94"
-
 [[package]]
 name = "matchit"
 version = "0.8.4"
@@ -464,7 +393,7 @@ dependencies = [
 name = "multipart_file"
 version = "0.1.0"
 dependencies = [
- "axum 0.7.5",
+ "axum",
  "lib",
  "tokio",
 ]
@@ -675,12 +604,6 @@ dependencies = [
  "unicode-ident",
 ]
 
-[[package]]
-name = "sync_wrapper"
-version = "0.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2047c6ded9c721764247e62cd3b03c09ffc529b2ba5b10ec482ae507a4a70160"
-
 [[package]]
 name = "sync_wrapper"
 version = "1.0.1"
@@ -758,7 +681,6 @@ dependencies = [
  "tokio",
  "tower-layer",
  "tower-service",
- "tracing",
 ]
 
 [[package]]
@@ -770,7 +692,7 @@ dependencies = [
  "futures-core",
  "futures-util",
  "pin-project-lite",
- "sync_wrapper 1.0.1",
+ "sync_wrapper",
  "tokio",
  "tower-layer",
  "tower-service",

examples/multipart_file/Cargo.toml

@@ -1,9 +1,9 @@
 [package]
 name = "multipart_file"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 
 [dependencies]
 lib = { path = "../..", features = ["axum"] }
-axum = "0.7.5"
+axum = "0.8"
-tokio = { version = "1.40", features = ["rt-multi-thread", "macros"] }
+tokio = { version = "1.47", features = ["rt-multi-thread", "macros"] }

examples/multipart_file/src/main.rs

@@ -1,22 +1,10 @@
 use axum::extract::DefaultBodyLimit;
 use lib::axum::app::AppBuilder;
-use lib::axum::extractor::MultipartFiles;
+use lib::axum::extractor::{MultipartFile, MultipartFiles};
 use lib::routes;
 
-// 0 or more
+// 0 or more files
-async fn with_optional_file(files: Option<MultipartFiles>) -> String {
+async fn several_files(MultipartFiles(files): MultipartFiles) -> String {
-    format!(
-        "{:?}",
-        files.map(|files| files
-            .0
-            .into_iter()
-            .map(|file| file.filename)
-            .collect::<Vec<_>>())
-    )
-}
-
-// 1 or more files
-async fn handler(MultipartFiles(files): MultipartFiles) -> String {
     format!(
         "{:?} uploaded",
         files
@@ -26,11 +14,26 @@ async fn handler(MultipartFiles(files): MultipartFiles) -> String {
     )
 }
 
+// 1 file exactly
+async fn single_file(MultipartFile(file): MultipartFile) -> String {
+    format!("{:?} uploaded", file.filename)
+}
+
+// 0 or 1 file
+async fn optional_single_file(file: Option<MultipartFile>) -> String {
+    format!(
+        "{:?} uploaded",
+        file.map(|file| file.0.filename)
+            .unwrap_or(String::from("No file found"))
+    )
+}
+
 #[tokio::main]
 async fn main() {
     let route = routes!(
-        get "/" => handler,
+        get "/" => several_files,
-        get "/opt" => with_optional_file
+        get "/file" => single_file,
+        get "/opt/file" => optional_single_file
     )
     .layer(DefaultBodyLimit::disable());
     AppBuilder::new().route(route).serve().await.unwrap();

src/axum/extractor.rs

@@ -1,10 +1,11 @@
-use axum::{
+use axum::extract::FromRequest;
-    extract::{
+use axum::extract::Multipart;
-        FromRequest, Multipart, Request,
+use axum::extract::OptionalFromRequest;
-        multipart::{Field, MultipartError, MultipartRejection},
+use axum::extract::Request;
-    },
+use axum::extract::multipart::Field;
-    response::IntoResponse,
+use axum::extract::multipart::MultipartError;
-};
+use axum::extract::multipart::MultipartRejection;
+use axum::response::IntoResponse;
 use mime::Mime;
 use std::str::FromStr;
 use thiserror::Error;
@@ -140,6 +141,40 @@ where
     }
 }
 
+impl<S> OptionalFromRequest<S> for MultipartFile
+where
+    S: Send + Sync,
+{
+    type Rejection = MultipartFileRejection;
+
+    /// Extracts a single file from a multipart request.
+    /// Expects exactly one file. A file must have a name, bytes and optionally a content type.
+    /// This extractor consumes the request and must ble placed last in the handler.
+    /// # Example
+    /// ```
+    /// use std::io::Read;
+    /// use axum::response::Html;
+    /// use lib::axum::extractor::{MultipartFile, MultipartFiles};
+    ///
+    /// async fn upload_file(opt_file: Option<MultipartFile>) -> Html<String> {
+    ///     Html(opt_file
+    ///         .map(|MultipartFile(file)| String::from_utf8(file.bytes).unwrap())
+    ///         .unwrap_or_else(|| String::from("<p>Not Found</p>"))
+    ///     )
+    /// }
+    /// ```
+    async fn from_request(req: Request, state: &S) -> Result<Option<Self>, Self::Rejection> {
+        let multipart = Multipart::from_request(req, state).await?;
+        let files = get_files(multipart).await?;
+        if files.len() > 1 {
+            Err(MultipartFileRejection::SeveralFiles)
+        } else {
+            let file = files.first().ok_or(MultipartFileRejection::NoFiles)?;
+            Ok(Some(MultipartFile(file.clone())))
+        }
+    }
+}
+
 impl<S> FromRequest<S> for MultipartFiles
 where
     S: Send + Sync,
@@ -147,7 +182,7 @@ where
     type Rejection = MultipartFileRejection;
 
     /// Extracts multiple files from a multipart request.
-    /// Expects at least one file. A file must have a name, bytes and optionally a content type.
+    /// Can contain 0 files. A file must have a name, bytes and optionally a content type.
     /// This extractor consumes the request and must ble placed last in the handler.
     /// # Example
     /// ```
@@ -167,12 +202,8 @@ where
     async fn from_request(req: Request, state: &S) -> Result<Self, Self::Rejection> {
         let multipart = Multipart::from_request(req, state).await?;
         let files = get_files(multipart).await?;
-        if files.is_empty() {
-            Err(MultipartFileRejection::NoFiles)
-        } else {
         Ok(MultipartFiles(files))
     }
-    }
 }
 
 async fn get_files(mut multipart: Multipart) -> Result<Vec<File>, MultipartFileRejection> {