fix(formatter): Honor trailing ignore comments after list separators

crates/oxc_formatter/src/ast_nodes/generated/format.rs

@@ -25,6 +25,17 @@ impl<'a> Format<'a> for AstNode<'a, Program<'a>> {
 impl<'a> Format<'a> for AstNode<'a, Expression<'a>> {
     #[inline]
     fn fmt(&self, f: &mut Formatter<'_, 'a>) {
+        if f.comments().has_trailing_suppression_comment(self.span().end) {
+            format_leading_comments(self.span()).fmt(f);
+            FormatSuppressedNode(self.span()).fmt(f);
+            format_trailing_comments(
+                self.parent.span(),
+                self.inner.span(),
+                self.following_span_start,
+            )
+            .fmt(f);
+            return;
+        }
         let allocator = self.allocator;
         let parent = self.parent;
         match self.inner {

crates/oxc_formatter/src/formatter/comments.rs

@@ -140,6 +140,35 @@ pub struct Comments<'a> {
 }
 
 impl<'a> Comments<'a> {
+    #[inline]
+    const fn is_end_of_line_comment_gap_byte(byte: u8) -> bool {
+        matches!(byte, b'\t' | b' ' | b'=' | b':')
+    }
+
+    #[inline]
+    const fn is_trailing_suppression_gap_byte(byte: u8) -> bool {
+        Self::is_end_of_line_comment_gap_byte(byte) || matches!(byte, b',' | b';')
+    }
+
+    fn end_of_line_comments_after_with(
+        &self,
+        mut pos: u32,
+        is_allowed_gap_byte: impl Fn(u8) -> bool + Copy,
+    ) -> &'a [Comment] {
+        let comments = self.comments_after(pos);
+        for (index, comment) in comments.iter().enumerate() {
+            if self.source_text.all_bytes_match(pos, comment.span.start, is_allowed_gap_byte) {
+                if comment.is_line() || comment.followed_by_newline() {
+                    return &comments[..=index];
+                }
+                pos = comment.span.end;
+            } else {
+                break;
+            }
+        }
+        &[]
+    }
+
     pub fn new(source_text: SourceText<'a>, comments: &'a [Comment]) -> Self {
         Comments {
             source_text,
@@ -194,21 +223,8 @@ impl<'a> Comments<'a> {
     }
 
     /// Returns end-of-line comments that are after the given position (excluding printed ones).
-    pub fn end_of_line_comments_after(&self, mut pos: u32) -> &'a [Comment] {
-        let comments = self.comments_after(pos);
-        for (index, comment) in comments.iter().enumerate() {
-            if self.source_text.all_bytes_match(pos, comment.span.start, |b| {
-                matches!(b, b'\t' | b' ' | b'=' | b':')
-            }) {
-                if comment.is_line() || comment.followed_by_newline() {
-                    return &comments[..=index];
-                }
-                pos = comment.span.end;
-            } else {
-                break;
-            }
-        }
-        &[]
+    pub fn end_of_line_comments_after(&self, pos: u32) -> &'a [Comment] {
+        self.end_of_line_comments_after_with(pos, Self::is_end_of_line_comment_gap_byte)
     }
 
     /// Returns comments that start after the given position (excluding printed ones).
@@ -394,8 +410,9 @@ impl<'a> Comments<'a> {
     /// This supports patterns like:
     /// `statement(); // prettier-ignore`
     /// `statement(); /* prettier-ignore */`
+    /// `value, // prettier-ignore`
     pub fn has_trailing_suppression_comment(&self, pos: u32) -> bool {
-        self.end_of_line_comments_after(pos)
+        self.end_of_line_comments_after_with(pos, Self::is_trailing_suppression_gap_byte)
             .iter()
             .any(|comment| self.is_suppression_comment(comment))
     }

crates/oxc_formatter/tests/fixtures/js/ignore/oxfmt.js

@@ -65,6 +65,10 @@ export const item={  a:1,b:2}; // prettier-ignore
 const config={  retries:10,timeout:5000}; // prettier-ignore
 let data=[ 1,2,3 ]; // prettier-ignore
 
+const items = [
+  {a:aa(),b:bb(),c:cc(),d:dd(),e:ee(),f:ff(),g:gg()}, // prettier-ignore
+];
+
 function demo() {
   return   {a:1,b:2}; // prettier-ignore
 }

crates/oxc_formatter/tests/fixtures/js/ignore/oxfmt.js.snap

@@ -1,5 +1,6 @@
 ---
 source: crates/oxc_formatter/tests/fixtures/mod.rs
+assertion_line: 229
 ---
 ==================== Input ====================
 // This file copies from https://github.com/prettier/prettier/blob/main/tests/format/js/ignore/ignore.js,
@@ -69,6 +70,10 @@ export const item={  a:1,b:2}; // prettier-ignore
 const config={  retries:10,timeout:5000}; // prettier-ignore
 let data=[ 1,2,3 ]; // prettier-ignore
 
+const items = [
+  {a:aa(),b:bb(),c:cc(),d:dd(),e:ee(),f:ff(),g:gg()}, // prettier-ignore
+];
+
 function demo() {
   return   {a:1,b:2}; // prettier-ignore
 }
@@ -169,6 +174,10 @@ export const item={  a:1,b:2}; // prettier-ignore
 const config={  retries:10,timeout:5000}; // prettier-ignore
 let data=[ 1,2,3 ]; // prettier-ignore
 
+const items = [
+  {a:aa(),b:bb(),c:cc(),d:dd(),e:ee(),f:ff(),g:gg()}, // prettier-ignore
+];
+
 function demo() {
   return   {a:1,b:2}; // prettier-ignore
 }
@@ -268,6 +277,10 @@ export const item={  a:1,b:2}; // prettier-ignore
 const config={  retries:10,timeout:5000}; // prettier-ignore
 let data=[ 1,2,3 ]; // prettier-ignore
 
+const items = [
+  {a:aa(),b:bb(),c:cc(),d:dd(),e:ee(),f:ff(),g:gg()}, // prettier-ignore
+];
+
 function demo() {
   return   {a:1,b:2}; // prettier-ignore
 }

tasks/ast_tools/src/generators/formatter/format.rs

@@ -318,22 +318,34 @@ fn generate_enum_implementation(enum_def: &EnumDef, schema: &Schema) -> TokenStr
     };
     let node_type = get_node_type(&enum_ty);
 
-    let inline_trailing_suppression = if enum_def.name() == "Statement" {
-        // Expression statements need specialized ASI-safe suppression handling in
-        // `AstNode<ExpressionStatement>::write`.
-        quote! {
-            if !matches!(self.inner, Statement::ExpressionStatement(_))
-                && f.comments().has_trailing_suppression_comment(self.span().end)
-            {
-                format_leading_comments(self.span()).fmt(f);
-                FormatSuppressedNode(self.span()).fmt(f);
-                format_trailing_comments(self.parent.span(), self.inner.span(), self.following_span_start)
-                    .fmt(f);
-                return;
+    let inline_trailing_suppression = match enum_def.name() {
+        "Statement" => {
+            // Expression statements need specialized ASI-safe suppression handling in
+            // `AstNode<ExpressionStatement>::write`.
+            quote! {
+                if !matches!(self.inner, Statement::ExpressionStatement(_))
+                    && f.comments().has_trailing_suppression_comment(self.span().end)
+                {
+                    format_leading_comments(self.span()).fmt(f);
+                    FormatSuppressedNode(self.span()).fmt(f);
+                    format_trailing_comments(self.parent.span(), self.inner.span(), self.following_span_start)
+                        .fmt(f);
+                    return;
+                }
             }
         }
-    } else {
-        quote! {}
+        "Expression" => {
+            quote! {
+                if f.comments().has_trailing_suppression_comment(self.span().end) {
+                    format_leading_comments(self.span()).fmt(f);
+                    FormatSuppressedNode(self.span()).fmt(f);
+                    format_trailing_comments(self.parent.span(), self.inner.span(), self.following_span_start)
+                        .fmt(f);
+                    return;
+                }
+            }
+        }
+        _ => quote! {},
     };
 
     quote! {