fix(js_formatter): correctly handle line terminators in JSX string

CHANGELOG.md

@@ -236,6 +236,7 @@ our [guidelines for writing a good changelog entry](https://github.com/biomejs/b
 - Fix [#2470](https://github.com/biomejs/biome/issues/2470) by avoid introducing linebreaks in single line string interpolations. Contributed by @ah-yu
 - Resolve deadlocks by narrowing the scope of locks. Contributed by @mechairoi
 - Fix [#2782](https://github.com/biomejs/biome/issues/2782) by computing the enabled rules by taking the override settings into consideration. Contributed by @ematipico
+- Fix [https://github.com/biomejs/biome/issues/2877] by correctly handling line terminators in JSX string. Contributed by @ah-yu
 
 ### JavaScript APIs
 

crates/biome_formatter/src/token/string.rs

@@ -140,8 +140,13 @@ pub fn normalize_string(
 ) -> Cow<str> {
     let alternate_quote = preferred_quote.other();
 
-    // A string should be manipulated only if its raw content contains backslash or quotes
-    if !raw_content.contains(['\\', preferred_quote.as_char(), alternate_quote.as_char()]) {
+    // A string should be manipulated only if its raw content contains backslash, quotes or line terminators
+    if !raw_content.contains([
+        '\\',
+        '\r',
+        preferred_quote.as_char(),
+        alternate_quote.as_char(),
+    ]) {
         return Cow::Borrowed(raw_content);
     }
 
@@ -264,3 +269,20 @@ pub fn normalize_string(
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn normalize_newline() {
+        assert_eq!(
+            normalize_string("a\nb", Quote::Double, true),
+            Cow::Borrowed("a\nb")
+        );
+        assert_eq!(
+            normalize_string("a\r\nb", Quote::Double, false),
+            Cow::Borrowed("a\nb")
+        );
+    }
+}

crates/biome_js_formatter/tests/specs/jsx/multiline_jsx_string/multiline_jsx_string.jsx

@@ -0,0 +1,2 @@
+<div className="px-1 px-2
+px-3"/>;

crates/biome_js_formatter/tests/specs/jsx/multiline_jsx_string/multiline_jsx_string.jsx.snap

@@ -0,0 +1,66 @@
+---
+source: crates/biome_formatter_test/src/snapshot_builder.rs
+info: jsx/multiline_jsx_string/multiline_jsx_string.jsx
+---
+# Input
+
+```jsx
+<div className="px-1 px-2
+px-3"/>;
+
+```
+
+
+=============================
+
+# Outputs
+
+## Output 1
+
+-----
+Indent style: Tab
+Indent width: 2
+Line ending: LF
+Line width: 80
+Quote style: Double Quotes
+JSX quote style: Double Quotes
+Quote properties: As needed
+Trailing commas: All
+Semicolons: Always
+Arrow parentheses: Always
+Bracket spacing: true
+Bracket same line: false
+Attribute Position: Auto
+-----
+
+```jsx
+<div
+	className="px-1 px-2
+px-3"
+/>;
+```
+
+## Output 1
+
+-----
+Indent style: Tab
+Indent width: 2
+Line ending: CRLF
+Line width: 80
+Quote style: Double Quotes
+JSX quote style: Double Quotes
+Quote properties: As needed
+Trailing commas: All
+Semicolons: Always
+Arrow parentheses: Always
+Bracket spacing: true
+Bracket same line: false
+Attribute Position: Auto
+-----
+
+```jsx
+<div<CRLF>
+	className="px-1 px-2<CRLF>
+px-3"<CRLF>
+/>;<CRLF>
+```

crates/biome_js_formatter/tests/specs/jsx/multiline_jsx_string/options.json

@@ -0,0 +1,6 @@
+{
+  "$schema": "../../../../../../packages/@biomejs/biome/configuration_schema.json",
+  "formatter": {
+    "lineEnding": "crlf"
+  }
+}