feat: suppport transform hook return map (#422)

crates/rolldown/src/bundler/module_loader/normal_module_task.rs

@@ -65,7 +65,8 @@ impl<'task, T: FileSystem + Default + 'static> NormalModuleTask<'task, T> {
         .await?;
 
     // Run plugin transform.
-    let source: Arc<str> = transform_source(&self.ctx.plugin_driver, source).await?.into();
+    let source: Arc<str> =
+      transform_source(&self.ctx.plugin_driver, source, &mut sourcemap_chain).await?.into();
 
     let (ast, scope, scan_result, ast_symbol, namespace_symbol) = self.scan(&source);
     tracing::trace!("scan {:?}", self.resolved_path);

crates/rolldown/src/bundler/plugin_driver/mod.rs

@@ -1,15 +1,16 @@
 use std::sync::Arc;
 
 use rolldown_error::BuildError;
+use rolldown_sourcemap::SourceMap;
 use rolldown_utils::block_on_spawn_all;
 
 use crate::{
   plugin::{
     args::{HookBuildEndArgs, RenderChunkArgs},
     plugin::{BoxPlugin, HookNoopReturn},
   },
-  HookLoadArgs, HookLoadReturn, HookResolveIdArgs, HookResolveIdReturn, HookTransformArgs,
-  HookTransformReturn, Output, PluginContext,
+  HookLoadArgs, HookLoadReturn, HookResolveIdArgs, HookResolveIdReturn, HookTransformArgs, Output,
+  PluginContext,
 };
 
 pub type SharedPluginDriver = Arc<PluginDriver>;
@@ -48,13 +49,24 @@ impl PluginDriver {
     Ok(None)
   }
 
-  pub async fn transform(&self, args: &HookTransformArgs<'_>) -> HookTransformReturn {
+  pub async fn transform(
+    &self,
+    args: &HookTransformArgs<'_>,
+  ) -> Result<(String, Vec<SourceMap>), BuildError> {
+    let mut sourcemap_chain = vec![];
+    let mut code = args.code.to_string();
     for plugin in &self.plugins {
-      if let Some(r) = plugin.transform(&mut PluginContext::new(), args).await? {
-        return Ok(Some(r));
+      if let Some(r) = plugin
+        .transform(&mut PluginContext::new(), &HookTransformArgs { id: args.id, code: &code })
+        .await?
+      {
+        code = r.code;
+        if let Some(map) = r.map {
+          sourcemap_chain.push(map);
+        }
       }
     }
-    Ok(None)
+    Ok((code, sourcemap_chain))
   }
 
   pub async fn build_end(&self, args: Option<&HookBuildEndArgs>) -> HookNoopReturn {

crates/rolldown/src/bundler/utils/transform_source.rs

@@ -1,14 +1,16 @@
+use rolldown_sourcemap::SourceMap;
+
 use crate::{bundler::plugin_driver::PluginDriver, error::BatchedErrors, HookTransformArgs};
 
 pub async fn transform_source(
   plugin_driver: &PluginDriver,
-  mut source: String,
+  source: String,
+  sourcemap_chain: &mut Vec<SourceMap>,
 ) -> Result<String, BatchedErrors> {
-  if let Some(r) =
-    plugin_driver.transform(&HookTransformArgs { id: source.as_ref(), code: &source }).await?
-  {
-    source = r.code;
-  };
+  let (code, map_chain) =
+    plugin_driver.transform(&HookTransformArgs { id: source.as_ref(), code: &source }).await?;
+
+  sourcemap_chain.extend(map_chain);
 
-  Ok(source)
+  Ok(code)
 }

packages/node/src/options/create-build-plugin-adapter.ts

@@ -207,7 +207,7 @@ function transform(hook: Plugin['transform']) {
           return
         }
         // TODO other filed
-        return { code: value.code }
+        return { code: value.code, map: transformSourcemap(value.map) }
       } catch (error) {
         console.error(error)
         throw error

packages/node/test/cases/plugin/transform/config.ts

@@ -13,6 +13,7 @@ const config: RollupOptions = {
           expect(code).toStrictEqual('')
           return {
             code: `console.log('foo')`,
+            map: { mappings: "" }
           }
         }
       },