Improve handling of trailing comments for the consequence of if statements.

Author: Dunqing

crates/oxc_formatter/src/write/utils/statement_body.rs

@@ -11,6 +11,7 @@ use crate::{
         trivia::FormatTrailingComments,
     },
     generated::ast_nodes::{AstNode, AstNodes},
+    utils::format_node_without_trailing_comments::FormatNodeWithoutTrailingComments,
     write,
     write::FormatWrite,
 };
@@ -50,24 +51,28 @@ impl<'a> Format<'a> for FormatStatementBody<'a, '_> {
                 [indent(&format_args!(
                     &soft_line_break_or_space(),
                     &format_once(|f| {
+                        // ```js
+                        // if (condition)
+                        //     statement; // comment1
+                        // // comment2
+                        // else {}
+                        // ```
+                        // The following logic is to ensure that `comment1` is printed as a trailing comment of the
+                        // statement, and leave `comment2` to be printed in the IfStatement's alternate.
+
+                        let body_span = self.body.span();
                         let is_consequent_of_if_statement_parent = matches!(
                             self.body.parent,
                             AstNodes::IfStatement(if_stmt)
-                            if if_stmt.consequent.span() == self.body.span() && if_stmt.alternate.is_some()
+                            if if_stmt.consequent.span() == body_span && if_stmt.alternate.is_some()
                         );
-                        if is_consequent_of_if_statement_parent
-                            && let AstNodes::ExpressionStatement(expression) =
-                                self.body.as_ast_nodes()
-                        {
-                            expression.format_leading_comments(f)?;
-                            expression.write(f)?;
-                            let comments = f
-                                .context()
-                                .comments()
-                                .comments_before_character(expression.span.end, b'\n');
+                        if is_consequent_of_if_statement_parent {
+                            write!(f, FormatNodeWithoutTrailingComments(self.body))?;
+                            let comments =
+                                f.context().comments().end_of_line_comments_after(body_span.end);
                             FormatTrailingComments::Comments(comments).fmt(f)
                         } else {
-                            self.body.fmt(f)
+                            write!(f, self.body)
                         }
                     })
                 ))]