files: inline disposition for common web app file types (#2257)

actix-files/src/lib.rs

@@ -279,6 +279,22 @@ mod tests {
         );
     }
 
+    #[actix_rt::test]
+    async fn test_named_file_javascript() {
+        let file = NamedFile::open("tests/test.js").unwrap();
+
+        let req = TestRequest::default().to_http_request();
+        let resp = file.respond_to(&req).await.unwrap();
+        assert_eq!(
+            resp.headers().get(header::CONTENT_TYPE).unwrap(),
+            "application/javascript"
+        );
+        assert_eq!(
+            resp.headers().get(header::CONTENT_DISPOSITION).unwrap(),
+            "inline; filename=\"test.js\""
+        );
+    }
+
     #[actix_rt::test]
     async fn test_named_file_image_attachment() {
         let cd = ContentDisposition {

actix-files/src/named.rs

@@ -120,6 +120,11 @@ impl NamedFile {
 
             let disposition = match ct.type_() {
                 mime::IMAGE | mime::TEXT | mime::VIDEO => DispositionType::Inline,
+                mime::APPLICATION => match ct.subtype() {
+                    mime::JAVASCRIPT | mime::JSON => DispositionType::Inline,
+                    name if name == "wasm" => DispositionType::Inline,
+                    _ => DispositionType::Attachment,
+                },
                 _ => DispositionType::Attachment,
             };
 
@@ -213,9 +218,11 @@ impl NamedFile {
 
     /// Set the Content-Disposition for serving this file. This allows
     /// changing the inline/attachment disposition as well as the filename
-    /// sent to the peer. By default the disposition is `inline` for text,
-    /// image, and video content types, and `attachment` otherwise, and
-    /// the filename is taken from the path provided in the `open` method
+    /// sent to the peer.
+    ///
+    /// By default the disposition is `inline` for `text/*`, `image/*`, `video/*` and
+    /// `application/{javascript, json, wasm}` mime types, and `attachment` otherwise,
+    /// and the filename is taken from the path provided in the `open` method
     /// after converting it to UTF-8 using.
     /// [`std::ffi::OsStr::to_string_lossy`]
     #[inline]