add prelude and fix empty gen

src/main.rs

@@ -53,6 +53,10 @@ async fn main() -> Result<()> {
     let merged_outputs = generator::file::combine_chunks(outputs)?;
     for output in merged_outputs.iter() {
         tracing::info!(?output, "Merged file");
+        let parent = output.path.parent().unwrap();
+        if !parent.exists() {
+            fs::create_dir_all(parent).await?;
+        }
         let mut file = fs::File::create(&output.path).await?;
         file.write_all(output.content.as_bytes()).await?;
     }