feat: impl Extend for BatchedErrors

crates/rolldown/src/error.rs

@@ -5,11 +5,6 @@ use smallvec::SmallVec;
 pub struct BatchedErrors(SmallVec<[BuildError; 1]>);
 
 impl BatchedErrors {
-  // TODO(hyf): using `trait Extend` would be more proper.
-  pub fn merge(&mut self, mut other: Self) {
-    self.0.append(&mut other.0);
-  }
-
   pub fn with_error(err: BuildError) -> Self {
     Self(smallvec::smallvec![err])
   }
@@ -50,6 +45,21 @@ pub fn into_batched_result<T>(value: Vec<Result<T, BuildError>>) -> BatchedResul
   }
 }
 
+impl Extend<BuildError> for BatchedErrors {
+  fn extend<T: IntoIterator<Item = BuildError>>(&mut self, iter: T) {
+    self.0.extend(iter.into_iter());
+  }
+}
+
+impl IntoIterator for BatchedErrors {
+  type Item = BuildError;
+  type IntoIter = smallvec::IntoIter<[BuildError; 1]>;
+
+  fn into_iter(self) -> Self::IntoIter {
+    self.0.into_iter()
+  }
+}
+
 pub type BatchedResult<T> = Result<T, BatchedErrors>;
 
 impl From<BuildError> for BatchedErrors {

crates/rolldown/src/module_loader/module_loader.rs

@@ -229,7 +229,7 @@ impl<T: FileSystem + 'static + Default> ModuleLoader<T> {
           runtime_brief = Some(runtime);
         }
         Msg::Errors(errs) => {
-          errors.merge(errs);
+          errors.extend(errs);
         }
       }
       self.remaining -= 1;

crates/rolldown/src/module_loader/normal_module_task.rs

@@ -240,7 +240,7 @@ impl<'task, T: FileSystem + Default + 'static> NormalModuleTask<'task, T> {
         ret.push(item);
       }
       Err(e) => {
-        errors.merge(e);
+        errors.extend(e);
       }
     });
     debug_assert!(errors.is_empty() && ret.len() == dependencies.len(), "{dependencies:#?}");