From 222550c7451c7807e8d0c5b473eb309985d85b32 Mon Sep 17 00:00:00 2001
From: greymoth <246701683+greymoth-jp@users.noreply.github.com>
Date: Tue, 30 Jun 2026 15:19:25 +0900
Subject: [PATCH] fix(csv-stringify): quote fields containing a bare CR or LF

A field holding a carriage return or line feed is left unquoted unless it
contains the configured record_delimiter (default "\n"), so a lone "\r"
fails to round-trip: parse auto-detects CR as a record delimiter and reports
CSV_RECORD_INCONSISTENT_FIELDS_LENGTH. Quote any field that contains CR or LF.
---
 packages/csv-stringify/lib/api/index.js                |  9 +++++++++
 packages/csv-stringify/test/option.record_delimiter.js | 10 ++++++++++
 2 files changed, 19 insertions(+)

diff --git a/packages/csv-stringify/lib/api/index.js b/packages/csv-stringify/lib/api/index.js
index 39de6053..bbfff9e4 100644
--- a/packages/csv-stringify/lib/api/index.js
+++ b/packages/csv-stringify/lib/api/index.js
@@ -212,6 +212,14 @@ const stringifier = function (options, state, info) {
             value,
             record_delimiter,
           );
+          // `parse` treats CR, LF and CRLF as record delimiters when
+          // `record_delimiter` is left to auto-detection (its default), so a
+          // field holding a bare CR or LF starts a new record and must be
+          // quoted to round-trip, even when it does not contain the configured
+          // `record_delimiter` (eg a lone "\r" stringified with the default
+          // "\n" record delimiter).
+          const containsNewline =
+            value.indexOf("\r") !== -1 || value.indexOf("\n") !== -1;
           const quotedString = quoted_string && typeof field === "string";
           let quotedMatch =
             quoted_match &&
@@ -249,6 +257,7 @@ const stringifier = function (options, state, info) {
             containsQuote === true ||
             containsdelimiter ||
             containsRecordDelimiter ||
+            containsNewline ||
             quoted ||
             quotedString ||
             quotedMatch;
diff --git a/packages/csv-stringify/test/option.record_delimiter.js b/packages/csv-stringify/test/option.record_delimiter.js
index 44181a6f..1a399a9a 100644
--- a/packages/csv-stringify/test/option.record_delimiter.js
+++ b/packages/csv-stringify/test/option.record_delimiter.js
@@ -31,4 +31,14 @@ describe("Option `record_delimiter`", function () {
       },
     );
   });
+  it("quote a field containing a bare carriage return", function (next) {
+    // `parse` treats a lone CR as a record delimiter under its default
+    // auto-detection, so a field holding a CR must be quoted to round-trip even
+    // though it does not contain the default "\n" record delimiter.
+    stringify([["x\ry", "z"]], { eof: false }, (err, data) => {
+      if (err) return next(err);
+      data.toString().should.eql('"x\ry",z');
+      next();
+    });
+  });
 });