Problem

Disclaimer: the problem occured to me, AI was used to minify the breaking code and summarize the issue. I hope that is OK

dx fmt --file rewrites a valid Dioxus RSX event handler into invalid Rust.

The breakage appears when an onclick: { ... } handler contains:

• an outer #[cfg(...)] let
• a move |_| { ... } closure
• an inner #[cfg(...)] let
• an if let Err(err) block with error.set(format!(...))

After formatting, dx fmt inserts stray fragments like .clone(); and truncates the error.set(format!(...)) call, so the file no longer compiles.

Steps To Reproduce

Steps to reproduce the behavior:

• Save this as repro.rs:

  use dioxus::prelude::*;
  
  fn app() -> Element {
      let mut uploading = use_signal(|| false);
      let mut error = use_signal(String::new);
      let create_photo_collection = String::new();
  
      rsx! {
          button {
              onclick: {
                  #[cfg(target_os = "android")]
                  let create_photo_collection_gallery = create_photo_collection.clone();
  
                  move |_| {
                      uploading.set(true);
                      error.set(String::new());
  
                      #[cfg(target_os = "android")]
                      let create_photo_collection_gallery_call =
                          create_photo_collection_gallery.clone();
  
                      if let Err(err) = Err::<(), _>("x") {
                          error.set(format!(
                              "{}: {}",
                              "err",
                              err
                          ));
                          uploading.set(false);
                          return;
                      }
                  }
              },
              "x"
          }
      }
  }
  
  fn main() {}

• Run:

  dx fmt --file repro.rs

• Inspect the formatted file.

Expected behavior

dx fmt should preserve valid Rust/RSX and produce a formatted file that still compiles.

Instead, it rewrites the snippet into broken code like:

#[cfg(target_os = "android")]
let create_photo_collection_gallery_call =
    create_photo_collection_gallery.clone();
    .clone();

if let Err(err) = Err::<(), _>("x") {
    err
    ));
    uploading.set(false);
    return;
}

Screenshots

N/A

Environment:

• Dioxus version: dioxus 0.7.7
• Rust version: rustc 1.95.0
• OS info: Linux
• App platform: N/A (formatter / RSX source issue)