span for minify

turbopack/crates/turbopack-ecmascript/src/minify.rs

@@ -1,4 +1,4 @@
-use std::{io::Write, sync::Arc};
+use std::{borrow::Cow, io::Write, sync::Arc};
 
 use anyhow::{bail, Context, Result};
 use swc_core::{
@@ -19,7 +19,8 @@ use swc_core::{
         transforms::base::fixer::paren_remover,
     },
 };
-use turbo_tasks::{ResolvedVc, Vc};
+use tracing::{field::Empty, Instrument};
+use turbo_tasks::{ResolvedVc, ValueToString, Vc};
 use turbo_tasks_fs::FileSystemPath;
 use turbopack_core::{
     code_builder::{Code, CodeBuilder},
@@ -34,6 +35,22 @@ pub async fn minify(
     code: Vc<Code>,
     source_maps: Vc<bool>,
 ) -> Result<Vc<Code>> {
+    let code_ref = code.await?;
+    let code_str = code_ref.source_code().to_str()?;
+    let span = tracing::info_span!("minify", path = %path.to_string().await?, input_len = code_str.len(), output_len = Empty);
+    let code = async move { minify_inner(path, code, code_str, source_maps).await }
+        .instrument(span.clone())
+        .await?;
+    span.record("output_len", code.source_code().len());
+    Ok(code.cell())
+}
+
+pub async fn minify_inner(
+    path: Vc<FileSystemPath>,
+    code: Vc<Code>,
+    code_str: Cow<'_, str>,
+    source_maps: Vc<bool>,
+) -> Result<Code> {
     let path = path.await?;
     let source_maps = source_maps.await?.then(|| code.generate_source_map());
     let code = code.await?;
@@ -43,7 +60,7 @@ pub async fn minify(
         let compiler = Arc::new(Compiler::new(cm.clone()));
         let fm = compiler.cm.new_source_file(
             FileName::Custom(path.path.to_string()).into(),
-            code.source_code().to_str()?.into_owned(),
+            code_str.into_owned(),
         );
 
         let lexer = Lexer::new(
@@ -134,7 +151,7 @@ pub async fn minify(
     } else {
         builder.push_source(&src.into(), None);
     }
-    Ok(builder.build().cell())
+    Ok(builder.build())
 }
 
 // From https://github.com/swc-project/swc/blob/11efd4e7c5e8081f8af141099d3459c3534c1e1d/crates/swc/src/lib.rs#L523-L560