fix(formatter): incorrect handling of CRLF for multiline block comment

.gitattributes

@@ -1,3 +1,4 @@
 crates/oxc_formatter/tests/fixtures/** text=auto eol=lf
+crates/oxc_formatter/tests/fixtures/js/crlf text=auto eol=crlf
 apps/oxfmt/test/fixtures/** text=auto eol=lf
 apps/oxlint/test/fixtures/** text=auto eol=lf

crates/oxc_formatter/src/formatter/trivia.rs

@@ -56,8 +56,10 @@
 //! 2. Applies indentation based on container type (block, soft, none)
 //! 3. Preserves comment relationships and spacing
 //! 4. Advances cursor for processed comments
+use oxc_allocator::StringBuilder;
 use oxc_ast::{Comment, CommentContent, CommentKind};
 use oxc_span::Span;
+use oxc_syntax::line_terminator::LineTerminatorSplitter;
 
 use crate::write;
 
@@ -427,20 +429,32 @@ impl<'a> Format<'a> for FormatDanglingComments<'a> {
 
 impl<'a> Format<'a> for Comment {
     fn fmt(&self, f: &mut Formatter<'_, 'a>) {
-        let source_text = f.source_text().text_for(&self.span).trim_end();
-        if is_alignable_comment(source_text) {
-            let mut lines = source_text.lines();
-
-            // `is_alignable_comment` only returns `true` for multiline comments
-            let first_line = lines.next().unwrap();
-            write!(f, [text(first_line.trim_end())]);
-
-            // Indent the remaining lines by one space so that all `*` are aligned.
-            for line in lines {
-                write!(f, [hard_line_break(), " ", text(line.trim())]);
+        let content = f.source_text().text_for(&self.span);
+        if content.bytes().any(|b| b == b'\n' || b == b'\r') {
+            let mut lines = LineTerminatorSplitter::new(content);
+            if is_alignable_comment(content) {
+                // `unwrap` is safe because `content` contains at least one line.
+                let first_line = lines.next().unwrap();
+                write!(f, [text(first_line.trim_end())]);
+
+                // Indent the remaining lines by one space so that all `*` are aligned.
+                for line in lines {
+                    write!(f, [hard_line_break(), " ", text(line.trim())]);
+                }
+            } else {
+                // Normalize line endings `\r\n` to `\n`
+                let mut string = StringBuilder::with_capacity_in(content.len(), f.allocator());
+                // `unwrap` is safe because `content` contains at least one line.
+                string.push_str(lines.next().unwrap().trim_end());
+
+                for str in lines {
+                    string.push('\n');
+                    string.push_str(str);
+                }
+                write!(f, [text(string.into_str())]);
             }
         } else {
-            write!(f, [text(source_text)]);
+            write!(f, [text(content.trim_end())]);
         }
     }
 }
@@ -475,11 +489,6 @@ impl<'a> Format<'a> for Comment {
 ///  */
 /// "#)));
 /// ```
-pub fn is_alignable_comment(source_text: &str) -> bool {
-    if !source_text.contains('\n') {
-        return false;
-    }
-    source_text.lines().enumerate().all(|(index, line)| {
-        if index == 0 { line.starts_with("/*") } else { line.trim_start().starts_with('*') }
-    })
+pub fn is_alignable_comment(lines: &str) -> bool {
+    LineTerminatorSplitter::new(lines).skip(1).all(|line| line.trim_start().starts_with('*'))
 }

crates/oxc_formatter/tests/fixtures/js/crlf/block-comment.js

@@ -0,0 +1,13 @@
+/*
+multi
+line
+block
+*/
+
+/**
+ * js doc
+ * @type {string}
+ * @description This is a description.
+ */
+
+// single line comment

crates/oxc_formatter/tests/fixtures/js/crlf/block-comment.js.snap

@@ -0,0 +1,88 @@
+---
+source: crates/oxc_formatter/tests/fixtures/mod.rs
+---
+==================== Input ====================
+/*
+multi
+line
+block
+*/
+
+/**
+ * js doc
+ * @type {string}
+ * @description This is a description.
+ */
+
+// single line comment
+
+==================== Output ====================
+-----------------------------------
+{ endOfLine: "lf", printWidth: 80 }
+-----------------------------------
+/*
+multi
+line
+block
+*/
+
+/**
+ * js doc
+ * @type {string}
+ * @description This is a description.
+ */
+
+// single line comment
+
+------------------------------------
+{ endOfLine: "lf", printWidth: 100 }
+------------------------------------
+/*
+multi
+line
+block
+*/
+
+/**
+ * js doc
+ * @type {string}
+ * @description This is a description.
+ */
+
+// single line comment
+
+-------------------------------------
+{ endOfLine: "crlf", printWidth: 80 }
+-------------------------------------
+/*
+multi
+line
+block
+*/
+
+/**
+ * js doc
+ * @type {string}
+ * @description This is a description.
+ */
+
+// single line comment
+
+--------------------------------------
+{ endOfLine: "crlf", printWidth: 100 }
+--------------------------------------
+/*
+multi
+line
+block
+*/
+
+/**
+ * js doc
+ * @type {string}
+ * @description This is a description.
+ */
+
+// single line comment
+
+===================== End =====================

crates/oxc_formatter/tests/fixtures/js/crlf/options.json

@@ -0,0 +1,8 @@
+[
+  {
+    "endOfLine": "lf"
+  },
+  {
+    "endOfLine": "crlf"
+  }
+]

crates/oxc_formatter/tests/fixtures/mod.rs

@@ -3,7 +3,7 @@ use std::{env::current_dir, fs, path::Path};
 use oxc_allocator::Allocator;
 use oxc_formatter::{
     ArrowParentheses, BracketSameLine, BracketSpacing, FormatOptions, Formatter, IndentStyle,
-    IndentWidth, LineWidth, QuoteStyle, Semicolons, TrailingCommas, get_parse_options,
+    IndentWidth, LineEnding, LineWidth, QuoteStyle, Semicolons, TrailingCommas, get_parse_options,
 };
 use oxc_parser::Parser;
 use oxc_span::SourceType;
@@ -108,6 +108,16 @@ fn parse_format_options(json: &OptionSet) -> FormatOptions {
                     options.bracket_same_line = BracketSameLine::from(b);
                 }
             }
+            "endOfLine" => {
+                if let Some(s) = value.as_str() {
+                    options.line_ending = match s {
+                        "lf" => LineEnding::Lf,
+                        "crlf" => LineEnding::Crlf,
+                        "cr" => LineEnding::Cr,
+                        _ => LineEnding::default(),
+                    };
+                }
+            }
             _ => {}
         }
     }