fix(formatter): print JSDoc embedded snippets with LF (#27821)

Otherwise, CRLF is appeared in IR, then panics.

apps/oxfmt/src/core/embed/prettier_string.rs

@@ -21,7 +21,7 @@ use oxc_formatter_core::{StringEmbedder, TailwindSorter};
 use crate::core::{
     embed::{FormatEmbeddedWithConfigCallback, dispatcher, jsdoc_fence},
     language::{Route, route_embedded},
-    options::inject_print_width,
+    options::inject_string_embed_options,
 };
 
 /// Build the napi build's string embedder installed on the session.
@@ -62,8 +62,8 @@ pub fn build_string_embedder(
             let Some(mut options) = dispatch_config.prettier_options_for(prettier_language) else {
                 return Err(format!("No plugin enabled for parser: {parser_name}"));
             };
-            // The same effective width the native branch prints at
-            inject_print_width(&mut options, print_width);
+            // The same effective width and line ending the native branch prints with
+            inject_string_embed_options(&mut options, print_width);
             (format_embedded)(options, code)
                 .map(|mut code| {
                     // Remove trailing newline added by Prettier without allocation.

apps/oxfmt/src/core/options/mod.rs

@@ -37,7 +37,7 @@ pub use to_oxc_formatter_yaml::to_oxc_formatter_yaml;
 #[cfg(feature = "napi")]
 pub use to_prettier::{
     build_prettier_options, inject_filepath, inject_opt_in_plugin_payloads,
-    inject_oxfmt_plugin_payload, inject_parser, inject_print_width, inject_tailwind_plugin_payload,
-    to_prettier,
+    inject_oxfmt_plugin_payload, inject_parser, inject_string_embed_options,
+    inject_tailwind_plugin_payload, to_prettier,
 };
 pub use validate::{ValidatedOptions, validate};

apps/oxfmt/src/core/options/to_prettier.rs

@@ -172,9 +172,13 @@ pub fn inject_parser(opts: &mut Value, parser_name: &str) {
     as_object_mut(opts).insert("parser".to_string(), Value::String(parser_name.to_string()));
 }
 
-/// Inject `printWidth` key, overriding the configured one.
-pub fn inject_print_width(opts: &mut Value, print_width: usize) {
-    as_object_mut(opts).insert("printWidth".to_string(), Value::from(print_width));
+/// Inject the keys for a string re-embedded into the parent's IR, overriding the configured ones:
+/// - `printWidth`: the effective width at the embedding position
+/// - `endOfLine`: `lf`, since the IR only takes `\n`
+pub fn inject_string_embed_options(opts: &mut Value, print_width: usize) {
+    let opts = as_object_mut(opts);
+    opts.insert("printWidth".to_string(), Value::from(print_width));
+    opts.insert("endOfLine".to_string(), Value::from("lf"));
 }
 
 /// Inject `filepath` key.

crates/oxc_formatter/src/formatter/jsdoc/embedded.rs

@@ -1,4 +1,4 @@
-use oxc_formatter_core::{FormatSession, LineWidth};
+use oxc_formatter_core::{FormatSession, LineEnding, LineWidth};
 use oxc_span::SourceType;
 
 use crate::options::TrailingCommas;
@@ -25,6 +25,22 @@ fn parse_and_build<'a>(
     Some(code)
 }
 
+/// Options for a JS/TS snippet formatted to a string and re-embedded into the comment text.
+///
+/// - `line_ending` is `Lf`: the comment is IR text which only takes `\n`, the host converts once at the end
+/// - `jsdoc` / `sort_imports` / `sort_tailwindcss` are disabled (top-level concerns)
+pub(super) fn snippet_options(format_options: &JsFormatOptions, width: usize) -> JsFormatOptions {
+    let width = u16::try_from(width).unwrap_or(80).clamp(1, LineWidth::MAX);
+    JsFormatOptions {
+        line_ending: LineEnding::Lf,
+        line_width: LineWidth::try_from(width).unwrap(),
+        jsdoc: None,
+        sort_imports: None,
+        sort_tailwindcss: None,
+        ..format_options.clone()
+    }
+}
+
 /// Returns `true` if the fenced code block language is JS/TS/JSX/TSX (case-insensitive).
 pub(super) fn is_js_ts_lang(lang: &str) -> bool {
     ["js", "javascript", "jsx", "ts", "typescript", "tsx"]
@@ -111,16 +127,7 @@ pub(super) fn format_jsdoc_js_snippet(
     format_options: &JsFormatOptions,
     session: &FormatSession<'_>,
 ) -> Option<String> {
-    let width = u16::try_from(print_width).unwrap_or(80).clamp(1, 320);
-    let line_width = LineWidth::try_from(width).unwrap();
-
-    let base_options = JsFormatOptions {
-        line_width,
-        jsdoc: None,
-        sort_imports: None,
-        sort_tailwindcss: None,
-        ..format_options.clone()
-    };
+    let base_options = snippet_options(format_options, print_width);
 
     // Try to parse and format with the given source type
     let try_format = |code: &str, source_type: SourceType| {

crates/oxc_formatter/src/formatter/jsdoc/serialize.rs

@@ -1,7 +1,7 @@
 use std::borrow::Cow;
 
 use oxc_ast::Comment;
-use oxc_formatter_core::{FormatSession, LineWidth};
+use oxc_formatter_core::FormatSession;
 use oxc_jsdoc::JSDoc;
 use oxc_span::Span;
 
@@ -10,7 +10,7 @@ use crate::options::{JsdocOptions, QuoteStyle};
 use crate::{JsFormatOptions, write};
 
 use super::{
-    imports::process_import_tags, line_buffer::LineBuffer,
+    embedded::snippet_options, imports::process_import_tags, line_buffer::LineBuffer,
     mdast_serialize::format_description_mdast, normalize::normalize_tag_kind,
     param_order::reorder_param_tags,
 };
@@ -80,14 +80,7 @@ impl<'a, 'o> JsdocFormatter<'a, 'o> {
         // `commentContentPrintWidth` to Prettier's TS formatter. This lets the
         // formatter wrap complex types (object literals, function types) across
         // multiple lines when they exceed the available width.
-        let type_width = u16::try_from(wrap_width).unwrap_or(80).clamp(1, LineWidth::MAX);
-        let type_format_options = JsFormatOptions {
-            line_width: LineWidth::try_from(type_width).unwrap(),
-            jsdoc: None,
-            sort_imports: None,
-            sort_tailwindcss: None,
-            ..format_options.clone()
-        };
+        let type_format_options = snippet_options(format_options, wrap_width);
         Self {
             options,
             format_options,
@@ -1179,14 +1172,7 @@ mod tests {
     }
 
     fn fmt_type_width(type_str: &str, width: u16) -> Option<String> {
-        let opts = JsFormatOptions {
-            line_width: LineWidth::try_from(width).unwrap(),
-            jsdoc: None,
-            sort_imports: None,
-            sort_tailwindcss: None,
-            ..JsFormatOptions::default()
-        };
-        fmt_type_with_opts(type_str, &opts)
+        fmt_type_with_opts(type_str, &snippet_options(&JsFormatOptions::default(), width.into()))
     }
 
     #[test]

crates/oxc_formatter/tests/fixtures/js/jsdoc/crlf/multiline-type.js

@@ -0,0 +1,6 @@
+/**
+ * @returns {{ aaaaaaaaaaaaaaaa: string; bbbbbbbbbbbbbbbbbb: number }} x
+ * @example
+ * const x = { aaaaaaaaaaaaaaaa: 1, bbbbbbbbbbbbbbbbbb: 2 };
+ */
+function f() {}

crates/oxc_formatter/tests/fixtures/js/jsdoc/crlf/multiline-type.js.snap

@@ -0,0 +1,46 @@
+---
+source: crates/oxc_formatter/tests/fixtures/mod.rs
+---
+==================== Input ====================
+/**
+ * @returns {{ aaaaaaaaaaaaaaaa: string; bbbbbbbbbbbbbbbbbb: number }} x
+ * @example
+ * const x = { aaaaaaaaaaaaaaaa: 1, bbbbbbbbbbbbbbbbbb: 2 };
+ */
+function f() {}
+
+==================== Output ====================
+--------------------------------------------------
+{ endOfLine: "crlf", jsdoc: true, printWidth: 40 }
+--------------------------------------------------
+/**
+ * @example
+ *   const x = { aaaaaaaaaaaaaaaa: 1, bbbbbbbbbbbbbbbbbb: 2 };
+ * @returns {{
+ *   aaaaaaaaaaaaaaaa: string;
+ *   bbbbbbbbbbbbbbbbbb: number;
+ * }} X
+ */
+function f() {}
+
+--------------------------------------------------
+{ endOfLine: "crlf", jsdoc: true, printWidth: 80 }
+--------------------------------------------------
+/**
+ * @example
+ *   const x = { aaaaaaaaaaaaaaaa: 1, bbbbbbbbbbbbbbbbbb: 2 };
+ * @returns {{ aaaaaaaaaaaaaaaa: string; bbbbbbbbbbbbbbbbbb: number }} X
+ */
+function f() {}
+
+---------------------------------------------------
+{ endOfLine: "crlf", jsdoc: true, printWidth: 100 }
+---------------------------------------------------
+/**
+ * @example
+ *   const x = { aaaaaaaaaaaaaaaa: 1, bbbbbbbbbbbbbbbbbb: 2 };
+ * @returns {{ aaaaaaaaaaaaaaaa: string; bbbbbbbbbbbbbbbbbb: number }} X
+ */
+function f() {}
+
+===================== End =====================

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

@@ -0,0 +1 @@
+[{ "jsdoc": true, "endOfLine": "crlf", "printWidth": 40 }]

crates/oxc_formatter_core/src/session/mod.rs

@@ -7,8 +7,8 @@ use std::{cell::RefCell, rc::Rc, sync::Arc};
 use oxc_allocator::Allocator;
 
 use crate::{
-    DispatchPayload, DispatchRequest, DispatchResponse, Document, FormatDispatcher, PrinterOptions,
-    UniqueGroupIdBuilder,
+    DispatchPayload, DispatchRequest, DispatchResponse, Document, FormatDispatcher, LineEnding,
+    PrinterOptions, UniqueGroupIdBuilder,
 };
 
 /// Upper bound on nested embedded dispatches;
@@ -184,6 +184,7 @@ impl<'a> FormatSession<'a> {
     /// must come back as TEXT. The caller supplies `printer_options`, typically its own
     /// print options with the embedding position's effective width, and owns any
     /// re-embedding conventions (e.g. trailing-newline handling) on the returned text.
+    /// The line ending is always `Lf`: the text goes back into the parent's IR, which only takes `\n`.
     /// A text consumer has no parent index space, so the child's Tailwind classes
     /// collect in a fresh scope and sort locally instead of joining this session's scope.
     ///
@@ -205,7 +206,7 @@ impl<'a> FormatSession<'a> {
         };
 
         let code = Document::new(doc, scoped.take_sorted_tailwind_classes())
-            .print(text_len, printer_options)
+            .print(text_len, printer_options.with_line_ending(LineEnding::Lf))
             .map_err(|err| err.to_string())?
             .into_code();
         Ok(Some(code))