From ba4ca327843de62a83c1f9c32acc303bd6b8545f Mon Sep 17 00:00:00 2001
From: tsctx <91457664+tsctx@users.noreply.github.com>
Date: Tue, 14 Nov 2023 09:04:40 +0900
Subject: [PATCH] fix: implement `Headers#delete` correctly (#2430)

* fix: implement `Headers#delete` correctly

* fix: HeadersList

* test: add

* test: add comment

* revert
---
 lib/fetch/headers.js  |  4 ++--
 test/fetch/headers.js | 11 ++++++++++-
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/lib/fetch/headers.js b/lib/fetch/headers.js
index 035560428bc..cfdc8868efa 100644
--- a/lib/fetch/headers.js
+++ b/lib/fetch/headers.js
@@ -203,7 +203,7 @@ class HeadersList {
       this.cookies = null
     }
 
-    return this[kHeadersMap].delete(name)
+    this[kHeadersMap].delete(name)
   }
 
   // https://fetch.spec.whatwg.org/#concept-header-list-get
@@ -308,7 +308,7 @@ class Headers {
     // 7. Delete name from this’s header list.
     // 8. If this’s guard is "request-no-cors", then remove
     //    privileged no-CORS request headers from this.
-    return this[kHeadersList].delete(name)
+    this[kHeadersList].delete(name)
   }
 
   // https://fetch.spec.whatwg.org/#dom-headers-get
diff --git a/test/fetch/headers.js b/test/fetch/headers.js
index 5da1a1ded1f..48461103d78 100644
--- a/test/fetch/headers.js
+++ b/test/fetch/headers.js
@@ -160,7 +160,7 @@ tap.test('Headers append', t => {
 })
 
 tap.test('Headers delete', t => {
-  t.plan(3)
+  t.plan(4)
 
   t.test('deletes valid header entry from instance', t => {
     t.plan(3)
@@ -193,6 +193,15 @@ tap.test('Headers delete', t => {
     t.throws(() => headers.delete(), 'throws on missing namee')
     t.throws(() => headers.delete('invalid @ header ? name'), 'throws on invalid name')
   })
+
+  // https://github.com/nodejs/undici/issues/2429
+  t.test('`Headers#delete` returns undefined', t => {
+    t.plan(2)
+    const headers = new Headers({ test: 'test' })
+
+    t.same(headers.delete('test'), undefined)
+    t.same(headers.delete('test2'), undefined)
+  })
 })
 
 tap.test('Headers get', t => {