From 8987aba77e71ca53f73eedae9b0c40b1f7d94c3e Mon Sep 17 00:00:00 2001
From: Harry Chen <czy88840616@gmail.com>
Date: Fri, 26 Jul 2024 15:59:26 +0800
Subject: [PATCH] fix: single field when allowFieldsDuplication enabled (#3981)

---
 packages/upload/src/parse.ts     | 5 ++++-
 packages/upload/test/koa.test.ts | 2 ++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/packages/upload/src/parse.ts b/packages/upload/src/parse.ts
index 716c0ba21afb..3ecb638e0e47 100644
--- a/packages/upload/src/parse.ts
+++ b/packages/upload/src/parse.ts
@@ -5,8 +5,11 @@ const headSeparator = Buffer.from('\r\n\r\n');
 function saveFields(fields, key, value, allowFieldsDuplication) {
   if (allowFieldsDuplication) {
     if (!fields[key]) {
-      fields[key] = [value];
+      fields[key] = value;
     } else {
+      if (!Array.isArray(fields[key])) {
+        fields[key] = [fields[key]];
+      }
       fields[key].push(value);
     }
   } else {
diff --git a/packages/upload/test/koa.test.ts b/packages/upload/test/koa.test.ts
index aff58f6f2f61..5e781f98be11 100644
--- a/packages/upload/test/koa.test.ts
+++ b/packages/upload/test/koa.test.ts
@@ -232,12 +232,14 @@ describe('test/koa.test.ts', function () {
       await request.post('/upload')
         .field('name', 'form')
         .field('name', 'form2')
+        .field('nameOther', 'other')
         .attach('file', filePath)
         .expect(200)
         .then(async response => {
           assert(response.body.files.length === 1);
           assert(response.body.files[0].filename === 'test.pdf');
           assert(JSON.stringify(response.body.fields.name) === JSON.stringify(['form', 'form2']));
+          assert(response.body.fields.nameOther === 'other');
         });
     });
   });