Add multipart interaction form extraction

Cargo.lock

@@ -39,6 +39,7 @@ dependencies = [
  "matchit",
  "memchr",
  "mime",
+ "multer",
  "percent-encoding",
  "pin-project-lite",
  "rustversion",
@@ -85,6 +86,12 @@ dependencies = [
  "shlex",
 ]
 
+[[package]]
+name = "cfg-if"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
+
 [[package]]
 name = "cobs"
 version = "0.3.0"
@@ -106,6 +113,15 @@ version = "0.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "edd0f118536f44f5ccd48bcb8b111bdc3de888b58c74639dfb034a357d0f206d"
 
+[[package]]
+name = "encoding_rs"
+version = "0.8.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "75030f3c4f45dafd7586dd6780965a8c7e8e285a5ecb86713e63a79c5b2766f3"
+dependencies = [
+ "cfg-if",
+]
+
 [[package]]
 name = "equivalent"
 version = "1.0.2"
@@ -199,6 +215,12 @@ dependencies = [
  "pin-project-lite",
 ]
 
+[[package]]
+name = "httparse"
+version = "1.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6dbf3de79e51f3d586ab4cb9d5c3e2c14aa28ed23d180cf89b4df0454a69cc87"
+
 [[package]]
 name = "indexmap"
 version = "2.14.0"
@@ -233,6 +255,23 @@ version = "0.3.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6877bb514081ee2a7ff5ef9de3281f14a4dd4bceac4c09388074a6b5df8a139a"
 
+[[package]]
+name = "multer"
+version = "3.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "83e87776546dc87511aa5ee218730c92b666d7264ab6ed41f9d215af9cd5224b"
+dependencies = [
+ "bytes",
+ "encoding_rs",
+ "futures-util",
+ "http",
+ "httparse",
+ "memchr",
+ "mime",
+ "spin",
+ "version_check",
+]
+
 [[package]]
 name = "percent-encoding"
 version = "2.3.2"
@@ -381,6 +420,7 @@ dependencies = [
  "axum",
  "slhx-core",
  "slhx-js",
+ "tokio",
 ]
 
 [[package]]
@@ -418,6 +458,12 @@ dependencies = [
  "slhx-core",
 ]
 
+[[package]]
+name = "spin"
+version = "0.9.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6980e8d7511241f8acf4aebddbb1ff938df5eebe98691418c4468d0b72a96a67"
+
 [[package]]
 name = "streaming-iterator"
 version = "0.1.9"
@@ -461,6 +507,27 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "tokio"
+version = "1.52.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8fc7f01b389ac15039e4dc9531aa973a135d7a4135281b12d7c1bc79fd57fffe"
+dependencies = [
+ "pin-project-lite",
+ "tokio-macros",
+]
+
+[[package]]
+name = "tokio-macros"
+version = "2.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "385a6cb71ab9ab790c5fe8d67f1645e6c450a7ce006a33de03daa956cf70a496"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "tower"
 version = "0.5.3"
@@ -521,6 +588,12 @@ version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
 
+[[package]]
+name = "version_check"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
+
 [[package]]
 name = "zmij"
 version = "1.0.21"

slhx-axum/Cargo.toml

@@ -7,6 +7,9 @@ edition.workspace = true
 path = "src/lib.rs"
 
 [dependencies]
-axum = { version = "0.7", default-features = false }
+axum = { version = "0.7", default-features = false, features = ["multipart"] }
 slhx-core = { path = "../slhx-core" }
 slhx-js = { path = "../slhx-js" }
+
+[dev-dependencies]
+tokio = { version = "1", features = ["macros", "rt"] }

slhx-axum/src/lib.rs

@@ -1,6 +1,6 @@
 use axum::async_trait;
 use axum::body::{to_bytes, Body};
-use axum::extract::{FromRequest, FromRequestParts};
+use axum::extract::{FromRequest, FromRequestParts, Multipart};
 use axum::http::{header, request::Parts, HeaderMap, HeaderValue, Request, Response, StatusCode};
 use axum::response::IntoResponse;
 use slhx_core::{BuildFingerprint, EffectBatch, IntoEffect};
@@ -107,10 +107,19 @@ pub struct EffectResponse {
     pub batch: EffectBatch,
 }
 
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct InteractionFile {
+    pub name: String,
+    pub file_name: Option<String>,
+    pub content_type: Option<String>,
+    pub bytes: Vec<u8>,
+}
+
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub struct InteractionForm {
     pub handle_id: u32,
     fields: Vec<(String, String)>,
+    files: Vec<InteractionFile>,
 }
 
 pub struct HandlerRegistry {
@@ -143,11 +152,52 @@ impl InteractionForm {
         Self {
             handle_id,
             fields: fields.into_iter().collect(),
+            files: Vec::new(),
         }
     }
 
     pub fn parse_urlencoded(body: &[u8]) -> Result<Self, InteractionFormRejection> {
-        let fields = parse_urlencoded_pairs(body)?;
+        Self::from_parts(parse_urlencoded_pairs(body)?, Vec::new())
+    }
+
+    // req: multipart/001, req: multipart/002
+    pub async fn parse_multipart(mut multipart: Multipart) -> Result<Self, InteractionFormRejection> {
+        let mut fields = Vec::new();
+        let mut files = Vec::new();
+
+        while let Some(field) = multipart
+            .next_field()
+            .await
+            .map_err(|_| InteractionFormRejection::InvalidBody)?
+        {
+            let Some(name) = field.name().map(str::to_owned) else {
+                continue;
+            };
+            let file_name = field.file_name().map(str::to_owned);
+            let content_type = field.content_type().map(str::to_owned);
+            let bytes = field
+                .bytes()
+                .await
+                .map_err(|_| InteractionFormRejection::InvalidBody)?;
+
+            if file_name.is_some() {
+                files.push(InteractionFile {
+                    name,
+                    file_name,
+                    content_type,
+                    bytes: bytes.to_vec(),
+                });
+            } else {
+                let value = String::from_utf8(bytes.to_vec())
+                    .map_err(|_| InteractionFormRejection::InvalidBody)?;
+                fields.push((name, value));
+            }
+        }
+
+        Self::from_parts(fields, files)
+    }
+
+    fn from_parts(fields: Vec<(String, String)>, files: Vec<InteractionFile>) -> Result<Self, InteractionFormRejection> {
         let Some(handle) = fields
             .iter()
             .find_map(|(name, value)| (name == SLHX_HANDLE_FIELD).then_some(value))
@@ -157,7 +207,7 @@ impl InteractionForm {
         let handle_id = handle
             .parse::<u32>()
             .map_err(|_| InteractionFormRejection::InvalidHandle)?;
-        Ok(Self { handle_id, fields })
+        Ok(Self { handle_id, fields, files })
     }
 
     pub fn value(&self, name: &str) -> Option<&str> {
@@ -175,6 +225,14 @@ impl InteractionForm {
     pub fn fields(&self) -> &[(String, String)] {
         &self.fields
     }
+
+    pub fn files(&self) -> &[InteractionFile] {
+        &self.files
+    }
+
+    pub fn file(&self, name: &str) -> Option<&InteractionFile> {
+        self.files.iter().find(|file| file.name == name)
+    }
 }
 
 impl HandlerRegistry {
@@ -219,7 +277,7 @@ impl HandlerRegistry {
 impl IntoResponse for InteractionFormRejection {
     fn into_response(self) -> axum::response::Response {
         let (status, message) = match self {
-            Self::InvalidBody => (StatusCode::BAD_REQUEST, "invalid urlencoded slhx form body"),
+            Self::InvalidBody => (StatusCode::BAD_REQUEST, "invalid slhx form body"),
             Self::MissingHandle => (StatusCode::BAD_REQUEST, "missing __h slhx handle field"),
             Self::InvalidHandle => (StatusCode::BAD_REQUEST, "invalid __h slhx handle field"),
         };
@@ -235,6 +293,13 @@ where
     type Rejection = InteractionFormRejection;
 
     async fn from_request(req: Request<Body>, _state: &S) -> Result<Self, Self::Rejection> {
+        if is_multipart(req.headers()) {
+            let multipart = Multipart::from_request(req, _state)
+                .await
+                .map_err(|_| InteractionFormRejection::InvalidBody)?;
+            return Self::parse_multipart(multipart).await;
+        }
+
         let bytes = to_bytes(req.into_body(), 1024 * 1024)
             .await
             .map_err(|_| InteractionFormRejection::InvalidBody)?;
@@ -242,6 +307,18 @@ where
     }
 }
 
+fn is_multipart(headers: &HeaderMap) -> bool {
+    headers
+        .get(header::CONTENT_TYPE)
+        .and_then(|value| value.to_str().ok())
+        .is_some_and(|content_type| {
+            content_type
+                .split(';')
+                .next()
+                .is_some_and(|mime| mime.trim().eq_ignore_ascii_case("multipart/form-data"))
+        })
+}
+
 impl PageMode {
     pub fn from_headers(headers: &HeaderMap) -> Self {
         match headers.get(SLHX_PARTIAL_HEADER).and_then(|value| value.to_str().ok()) {
@@ -402,7 +479,8 @@ fn hex(byte: u8) -> Option<u8> {
 
 #[cfg(test)]
 mod tests {
-    use super::{html_with_root_fingerprint, BuildFingerprint};
+    use super::{html_with_root_fingerprint, BuildFingerprint, InteractionForm};
+    use axum::{body::Body, extract::FromRequest, http::Request};
 
     #[test]
     fn root_fingerprint_is_added_to_initial_root() {
@@ -426,4 +504,38 @@ mod tests {
 
         assert_eq!(html, "<main data-slhx-root data-slhx-fp=\"1\">Docs</main>");
     }
+
+    #[tokio::test]
+    async fn interaction_form_extracts_multipart_fields_and_files() {
+        let boundary = "slhx-test-boundary";
+        let body = concat!(
+            "--slhx-test-boundary\r\n",
+            "Content-Disposition: form-data; name=\"__h\"\r\n\r\n",
+            "7\r\n",
+            "--slhx-test-boundary\r\n",
+            "Content-Disposition: form-data; name=\"title\"\r\n\r\n",
+            "Report\r\n",
+            "--slhx-test-boundary\r\n",
+            "Content-Disposition: form-data; name=\"upload\"; filename=\"a.txt\"\r\n",
+            "Content-Type: text/plain\r\n\r\n",
+            "hello\r\n",
+            "--slhx-test-boundary--\r\n",
+        );
+        let request = Request::builder()
+            .header(
+                axum::http::header::CONTENT_TYPE,
+                format!("multipart/form-data; boundary={boundary}"),
+            )
+            .body(Body::from(body))
+            .unwrap();
+
+        let form = InteractionForm::from_request(request, &()).await.unwrap();
+
+        assert_eq!(form.handle_id, 7);
+        assert_eq!(form.value("title"), Some("Report"));
+        let file = form.file("upload").unwrap();
+        assert_eq!(file.file_name.as_deref(), Some("a.txt"));
+        assert_eq!(file.content_type.as_deref(), Some("text/plain"));
+        assert_eq!(file.bytes, b"hello");
+    }
 }