fix(formatter): incorrect formatting method chain with trailing comments (oxc-project#16027)

* close oxc-project#15983

Author: Dunqing

crates/oxc_formatter/src/utils/member_chain/chain_member.rs

@@ -55,6 +55,16 @@ impl ChainMember<'_, '_> {
     pub const fn is_computed_expression(&self) -> bool {
         matches!(self, Self::ComputedMember { .. })
     }
+
+    pub fn span(&self) -> oxc_span::Span {
+        match self {
+            Self::StaticMember(member) => member.span(),
+            Self::TSNonNullExpression(e) => e.span(),
+            Self::CallExpression { expression, .. } => expression.span(),
+            Self::ComputedMember(member) => member.span(),
+            Self::Node(node) => node.span(),
+        }
+    }
 }
 
 impl<'a> Format<'a> for ChainMember<'a, '_> {
@@ -64,7 +74,6 @@ impl<'a> Format<'a> for ChainMember<'a, '_> {
                 write!(
                     f,
                     [
-                        line_suffix_boundary(),
                         FormatLeadingComments::Comments(
                             f.context().comments().comments_before(member.property().span().start)
                         ),

crates/oxc_formatter/src/utils/member_chain/mod.rs

@@ -45,7 +45,7 @@ impl<'a, 'b> MemberChain<'a, 'b> {
         // `flattened_items` now contains only the nodes that should have a sequence of
         // `[ StaticMemberExpression -> AnyNode + CallExpression ]`
         let tail_groups =
-            compute_remaining_groups(chain_members.drain(remaining_members_start_index..));
+            compute_remaining_groups(chain_members.drain(remaining_members_start_index..), f);
         let head_group = MemberChainGroup::from(chain_members);
 
         let mut member_chain = Self { head: head_group, tail: tail_groups, root: call_expression };
@@ -300,11 +300,18 @@ fn get_split_index_of_head_and_tail_groups(members: &[ChainMember<'_, '_>]) -> u
 /// computes groups coming after the first group
 fn compute_remaining_groups<'a, 'b>(
     members: impl IntoIterator<Item = ChainMember<'a, 'b>>,
+    f: &Formatter<'_, 'a>,
 ) -> TailChainGroups<'a, 'b> {
     let mut has_seen_call_expression = false;
     let mut groups_builder = MemberChainGroupsBuilder::default();
 
     for member in members {
+        let span = member.span();
+        let has_trailing_comment =
+            f.comments().comments_after(span.end).first().is_some_and(|comment| {
+                f.source_text().bytes_range(span.end, comment.span.start).trim_ascii().is_empty()
+            });
+
         match member {
             // [0] should be appended at the end of the group instead of the
             // beginning of the next one
@@ -333,6 +340,14 @@ fn compute_remaining_groups<'a, 'b>(
             }
             ChainMember::Node(_) => unreachable!("Remaining members never have a `Node` variant"),
         }
+
+        // Close the group immediately if the node had any trailing comments to
+        // ensure those are printed in a trailing position for the token they
+        // were originally commenting
+        if has_trailing_comment {
+            groups_builder.close_group();
+            has_seen_call_expression = false;
+        }
     }
 
     groups_builder.finish()

crates/oxc_formatter/tests/fixtures/ts/member-chains/issue-15983.ts

@@ -0,0 +1,5 @@
+wow /** do something weird here */
+  .omg! /** do something weird here */
+  .map((x) => x.name) /** do something weird here */
+  .filter((x) => x.length > 3)
+  .sort((a, b) => a.length - b.length);

crates/oxc_formatter/tests/fixtures/ts/member-chains/issue-15983.ts.snap

@@ -0,0 +1,29 @@
+---
+source: crates/oxc_formatter/tests/fixtures/mod.rs
+---
+==================== Input ====================
+wow /** do something weird here */
+  .omg! /** do something weird here */
+  .map((x) => x.name) /** do something weird here */
+  .filter((x) => x.length > 3)
+  .sort((a, b) => a.length - b.length);
+==================== Output ====================
+------------------
+{ printWidth: 80 }
+------------------
+wow /** do something weird here */
+  .omg! /** do something weird here */
+  .map((x) => x.name) /** do something weird here */
+  .filter((x) => x.length > 3)
+  .sort((a, b) => a.length - b.length);
+
+-------------------
+{ printWidth: 100 }
+-------------------
+wow /** do something weird here */
+  .omg! /** do something weird here */
+  .map((x) => x.name) /** do something weird here */
+  .filter((x) => x.length > 3)
+  .sort((a, b) => a.length - b.length);
+
+===================== End =====================