fix: make outdir behavior compatible with rollup if file is used (rol…

…ldown#3304)

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### Description
close rolldown#3240
<!-- Please insert your description here and provide especially info
about the "what" this PR is solving -->

crates/rolldown/src/asset/asset_generator.rs

@@ -27,7 +27,7 @@ impl Generator for AssetGenerator {
       let preliminary_filename =
         ctx.chunk.asset_preliminary_filenames.get(&asset_module.idx).unpack();
       let file_path =
-        ctx.options.cwd.as_path().join(&ctx.options.dir).join(preliminary_filename.as_str());
+        ctx.options.cwd.as_path().join(&ctx.options.out_dir).join(preliminary_filename.as_str());
       let file_dir = file_path.parent().expect("chunk file name should have a parent");
       instantiated_chunks.push(InstantiatedChunk {
         origin_chunk: ctx.chunk_idx,

crates/rolldown/src/bundler.rs

@@ -13,7 +13,7 @@ use rolldown_fs::{FileSystem, OsFileSystem};
 use rolldown_plugin::{
   HookBuildEndArgs, HookRenderErrorArgs, SharedPluginDriver, __inner::SharedPluginable,
 };
-use std::{borrow::Cow, sync::Arc};
+use std::sync::Arc;
 use tracing_chrome::FlushGuard;
 
 pub struct Bundler {
@@ -99,11 +99,7 @@ impl Bundler {
   ) -> BuildResult<BundleOutput> {
     let mut output = self.bundle_up(scan_stage_output, /* is_write */ true).await?;
 
-    let dist_dir = if self.options.file.is_some() {
-      Cow::Borrowed(&self.options.cwd)
-    } else {
-      Cow::Owned(self.options.cwd.join(&self.options.dir))
-    };
+    let dist_dir = self.options.cwd.join(&self.options.out_dir);
 
     self.fs.create_dir_all(&dist_dir).map_err(|err| {
       anyhow::anyhow!("Could not create directory for output chunks: {:?}", dist_dir).context(err)

crates/rolldown/src/css/css_generator.rs

@@ -42,7 +42,7 @@ impl Generator for CssGenerator {
 
     // Here file path is generated by chunk file name template, it maybe including path segments.
     // So here need to read it's parent directory as file_dir.
-    let file_path = ctx.options.cwd.as_path().join(&ctx.options.dir).join(
+    let file_path = ctx.options.cwd.as_path().join(&ctx.options.out_dir).join(
       ctx
         .chunk
         .css_preliminary_filename

crates/rolldown/src/ecmascript/ecma_generator.rs

@@ -193,7 +193,7 @@ impl Generator for EcmaGenerator {
 
     // Here file path is generated by chunk file name template, it maybe including path segments.
     // So here need to read it's parent directory as file_dir.
-    let file_path = ctx.options.cwd.as_path().join(&ctx.options.dir).join(
+    let file_path = ctx.options.cwd.as_path().join(&ctx.options.out_dir).join(
       ctx
         .chunk
         .preliminary_filename

crates/rolldown/src/stages/generate_stage/mod.rs

@@ -271,7 +271,7 @@ impl<'a> GenerateStage<'a> {
           chunk.asset_absolute_preliminary_filenames.insert(
             module.idx,
             preliminary
-              .absolutize_with(self.options.cwd.join(&self.options.dir))
+              .absolutize_with(self.options.cwd.join(&self.options.out_dir))
               .expect_into_string(),
           );
           chunk.asset_preliminary_filenames.insert(module.idx, preliminary);
@@ -282,12 +282,12 @@ impl<'a> GenerateStage<'a> {
 
       chunk.absolute_preliminary_filename = Some(
         preliminary_filename
-          .absolutize_with(self.options.cwd.join(&self.options.dir))
+          .absolutize_with(self.options.cwd.join(&self.options.out_dir))
           .expect_into_string(),
       );
       chunk.css_absolute_preliminary_filename = Some(
         css_preliminary_filename
-          .absolutize_with(self.options.cwd.join(&self.options.dir))
+          .absolutize_with(self.options.cwd.join(&self.options.out_dir))
           .expect_into_string(),
       );
       chunk.preliminary_filename = Some(preliminary_filename);

crates/rolldown/src/utils/normalize_options.rs

@@ -1,3 +1,5 @@
+use std::path::Path;
+
 use oxc::transformer::InjectGlobalVariablesConfig;
 use rolldown_common::{
   Comments, GlobalsOutputOption, InjectImport, ModuleType, NormalizedBundlerOptions, OutputFormat,
@@ -142,6 +144,18 @@ pub fn normalize_options(mut raw_options: crate::BundlerOptions) -> NormalizeOpt
     _ => raw_options.inline_dynamic_imports.unwrap_or(false),
   };
 
+  // If the `file` is provided, use the parent directory of the file as the `out_dir`.
+  // Otherwise, use the `dir` if provided, or default to `dist`.
+  let out_dir = raw_options.file.as_ref().map_or_else(
+    || raw_options.dir.clone().unwrap_or_else(|| "dist".to_string()),
+    |file| {
+      Path::new(file.as_str())
+        .parent()
+        .map(|parent| parent.to_string_lossy().to_string())
+        .unwrap_or_default()
+    },
+  );
+
   let normalized = NormalizedBundlerOptions {
     input: raw_options.input.unwrap_or_default(),
     cwd: raw_options
@@ -170,7 +184,8 @@ pub fn normalize_options(mut raw_options: crate::BundlerOptions) -> NormalizeOpt
     intro: raw_options.intro,
     outro: raw_options.outro,
     es_module: raw_options.es_module.unwrap_or_default(),
-    dir: raw_options.dir.unwrap_or_else(|| "dist".to_string()),
+    dir: raw_options.dir,
+    out_dir,
     file: raw_options.file,
     format,
     exports: raw_options.exports.unwrap_or(crate::OutputExports::Auto),

crates/rolldown/src/watch/watcher_task.rs

@@ -85,7 +85,8 @@ impl WatcherTask {
     match result {
       Ok(()) => {
         self.emitter.emit(WatcherEvent::Event(BundleEvent::BundleEnd(BundleEndEventData {
-          output: bundler.options.cwd.join(&bundler.options.dir).to_string_lossy().to_string(),
+          // TODO Here should be the file if specified `file` option
+          output: bundler.options.cwd.join(&bundler.options.out_dir).to_string_lossy().to_string(),
           #[allow(clippy::cast_possible_truncation)]
           duration: start_time.elapsed().as_millis() as u32,
         })))?;

crates/rolldown/tests/rolldown/errors/invalid_option/invalid-output-file/_config.json

@@ -1,6 +1,6 @@
 {
   "config": {
-    "file": "dist.js",
+    "file": "dist/index.js",
     "name": "wrap"
   },
   "expectError": true

crates/rolldown/tests/rolldown/function/file/css/artifacts.snap

@@ -7,13 +7,13 @@ snapshot_kind: text
 ## dist/out.css
 
 ```css
+body {
+  background-color: #f0f0f0;
+}
 
 ```
-## dist/out.css
+## out.css
 
 ```css
-body {
-  background-color: #f0f0f0;
-}
 
 ```

crates/rolldown/tests/rolldown/function/file/js/_config.json

@@ -1,6 +1,6 @@
 {
   "config": {
-    "file": "dist/out.css"
+    "file": "dist/out.js"
   },
   "expectExecuted": false
 }

crates/rolldown/tests/rolldown/function/file/js/artifacts.snap

@@ -4,9 +4,9 @@ snapshot_kind: text
 ---
 # Assets
 
-## dist/out.css
+## out.js
 
-```css
+```js
 
 //#region main.js
 var main_default = "hello, world";

crates/rolldown/tests/rolldown/function/file/js_css/artifacts.snap

@@ -6,6 +6,14 @@ snapshot_kind: text
 
 ## dist/out.css
 
+```css
+body {
+  background-color: #f0f0f0;
+}
+
+```
+## out.css
+
 ```css
 
 //#region main.js
@@ -14,11 +22,3 @@ var main_default = "hello, world";
 //#endregion
 export { main_default as default };
 ```
-## dist/out.css
-
-```css
-body {
-  background-color: #f0f0f0;
-}
-
-```

crates/rolldown/tests/rolldown/warnings/invalid_option/invalid_output_dir_option/artifacts.snap

@@ -12,7 +12,7 @@ snapshot_kind: text
 ```
 # Assets
 
-## dist/main.js
+## main.js
 
 ```js
 

crates/rolldown/tests/snapshots/integration_rolldown__filename_with_hash.snap

@@ -4103,16 +4103,16 @@ snapshot_kind: text
 
 # tests/rolldown/function/file/css
 
-- dist/out.css => dist/out.css
+- out.css => out.css
 - dist/out.css
 
 # tests/rolldown/function/file/js
 
-- dist/out.css => dist/out.css
+- out.js => out.js
 
 # tests/rolldown/function/file/js_css
 
-- dist/out.css => dist/out.css
+- out.css => out.css
 - dist/out.css
 
 # tests/rolldown/function/format/app/export-all
@@ -5296,7 +5296,7 @@ snapshot_kind: text
 
 # tests/rolldown/warnings/invalid_option/invalid_output_dir_option
 
-- dist/main.js => dist/main.js
+- main.js => main.js
 
 # tests/rolldown/warnings/invalid_option/unsupported_code_splitting_format
 

crates/rolldown_binding/src/types/binding_normalized_options.rs

@@ -107,8 +107,7 @@ impl BindingNormalizedOptions {
 
   #[napi(getter)]
   pub fn dir(&self) -> Option<String> {
-    // NOTE: rollup returns undefined when `dir` is not set
-    Some(self.inner.dir.clone())
+    self.inner.dir.clone()
   }
 
   #[napi(getter)]

crates/rolldown_common/src/chunk/mod.rs

@@ -124,7 +124,12 @@ impl Chunk {
     make_unique_name: &mut impl FnMut(&ArcStr) -> ArcStr,
   ) -> anyhow::Result<PreliminaryFilename> {
     if let Some(file) = &options.file {
-      return Ok(PreliminaryFilename::new(file.clone(), None));
+      let basename = PathBuf::from(file)
+        .file_name()
+        .expect("The file should have basename")
+        .to_string_lossy()
+        .to_string();
+      return Ok(PreliminaryFilename::new(basename, None));
     }
     let filename_template = self.filename_template(options, rollup_pre_rendered_chunk).await?;
     let extracted_hash_pattern = extract_hash_pattern(filename_template.template());

crates/rolldown_common/src/inner_bundler_options/types/normalized_bundler_options.rs

@@ -46,7 +46,10 @@ pub struct NormalizedBundlerOptions {
   pub entry_filenames: ChunkFilenamesOutputOption,
   pub chunk_filenames: ChunkFilenamesOutputOption,
   pub asset_filenames: FilenameTemplate,
-  pub dir: String,
+  // The user specified output directory config
+  pub dir: Option<String>,
+  // The rolldown resolved output directory from `dir` or `file`.
+  pub out_dir: String,
   pub file: Option<String>,
   pub format: OutputFormat,
   pub exports: OutputExports,

crates/rolldown_testing/src/integration_test.rs

@@ -46,9 +46,9 @@ impl IntegrationTest {
     let mut bundler = Bundler::new(options);
 
     if self.test_meta.write_to_disk {
-      if bundler.options().dir.as_path().is_dir() {
-        std::fs::remove_dir_all(&bundler.options().dir)
-          .context(bundler.options().dir.clone())
+      if bundler.options().out_dir.as_path().is_dir() {
+        std::fs::remove_dir_all(&bundler.options().out_dir)
+          .context(bundler.options().out_dir.clone())
           .expect("Failed to clean the output directory");
       }
       bundler.write().await
@@ -73,7 +73,7 @@ impl IntegrationTest {
     let cwd = bundler.options().cwd.clone();
 
     let bundle_output = if self.test_meta.write_to_disk {
-      let abs_output_dir = cwd.join(&bundler.options().dir);
+      let abs_output_dir = cwd.join(&bundler.options().out_dir);
       if abs_output_dir.is_dir() {
         std::fs::remove_dir_all(&abs_output_dir)
           .context(format!("{abs_output_dir:?}"))
@@ -128,7 +128,7 @@ impl IntegrationTest {
       let cwd = bundler.options().cwd.clone();
 
       let bundle_output = if self.test_meta.write_to_disk {
-        let abs_output_dir = cwd.join(&bundler.options().dir);
+        let abs_output_dir = cwd.join(&bundler.options().out_dir);
         if abs_output_dir.is_dir() {
           std::fs::remove_dir_all(&abs_output_dir)
             .context(format!("{abs_output_dir:?}"))
@@ -440,7 +440,7 @@ impl IntegrationTest {
 
   fn execute_output_assets(bundler: &Bundler, test_title: &str) {
     let cwd = bundler.options().cwd.clone();
-    let dist_folder = cwd.join(&bundler.options().dir);
+    let dist_folder = cwd.join(&bundler.options().out_dir);
 
     let is_expect_executed_under_esm = matches!(bundler.options().format, OutputFormat::Esm)
       || (!matches!(bundler.options().format, OutputFormat::Cjs)

packages/rolldown/tests/fixtures/output/file/_config.ts

@@ -8,6 +8,6 @@ export default defineTest({
     },
   },
   afterTest: function (output) {
-    expect(output.output[0].fileName).toMatchInlineSnapshot(`"dist/out.js"`)
+    expect(output.output[0].fileName).toBe('out.js')
   },
 })

packages/rolldown/tests/fixtures/plugin/normalized-option/_config.ts

@@ -82,7 +82,7 @@ export default defineTest({
       expect(option.chunkFileNames).toBeInstanceOf(Function)
       expect(option.assetFileNames).toBe('assets/[name]-[hash][extname]')
       expect(option.file).toBe('dist/[name].js')
-      expect(option.dir).toBe('dist')
+      expect(option.dir).toBe(undefined)
       expect(option.format).toBe('umd')
       expect(option.exports).toBe('auto')
       expect(option.esModule).toBe('if-default-prop')