From a674743f5d45cb31389ec2edb9e4ec45060b2a6c Mon Sep 17 00:00:00 2001
From: Huanyi Xie <74809554+xiehuanyi@users.noreply.github.com>
Date: Mon, 12 Oct 2026 00:30:10 +0300
Subject: [PATCH] fix(csv-stringify): allow empty string column keys

---
 .../csv-stringify/lib/api/normalize_columns.js    |  2 +-
 packages/csv-stringify/test/option.columns.js     | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/packages/csv-stringify/lib/api/normalize_columns.js b/packages/csv-stringify/lib/api/normalize_columns.js
index 53e4b2700..130e2b066 100644
--- a/packages/csv-stringify/lib/api/normalize_columns.js
+++ b/packages/csv-stringify/lib/api/normalize_columns.js
@@ -27,7 +27,7 @@ const normalize_columns = function (columns) {
         column !== null &&
         !Array.isArray(column)
       ) {
-        if (!column.key) {
+        if (!column.key && column.key !== "") {
           return [
             Error('Invalid column definition: property "key" is required'),
           ];
diff --git a/packages/csv-stringify/test/option.columns.js b/packages/csv-stringify/test/option.columns.js
index a83bd1dd1..7002ee219 100644
--- a/packages/csv-stringify/test/option.columns.js
+++ b/packages/csv-stringify/test/option.columns.js
@@ -1,8 +1,23 @@
 import "should";
 import { stringify } from "../lib/index.js";
+import { stringify as stringifySync } from "../lib/sync.js";
 
 describe("Option `columns`", function () {
   describe("definition", function () {
+    it("accepts an empty record key with an explicit header", function () {
+      stringifySync([{ "": "value" }], {
+        columns: [{ key: "", header: "blank" }],
+        header: true,
+      }).should.eql("blank\nvalue\n");
+    });
+
+    it("accepts an empty record key with the default header", function () {
+      stringifySync([{ "": "value" }], {
+        columns: [{ key: "" }],
+        header: true,
+      }).should.eql("\nvalue\n");
+    });
+
     it("validates option types", function () {
       (() => {
         stringify([], { columns: true }, () => {});