From 8576bf69fcb7dbb3c85e382f35d6443d76d7ca04 Mon Sep 17 00:00:00 2001
From: Mathias Lundell <lundell.mathias@gmail.com>
Date: Tue, 17 Dec 2024 15:07:22 +0100
Subject: [PATCH 1/2] fix: undefined function called

---
 lib/interceptor/dns.js   |  6 +++-
 test/interceptors/dns.js | 62 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+), 1 deletion(-)

diff --git a/lib/interceptor/dns.js b/lib/interceptor/dns.js
index fc5dc1a4366..98ef376ecbb 100644
--- a/lib/interceptor/dns.js
+++ b/lib/interceptor/dns.js
@@ -213,6 +213,10 @@ class DNSInstance {
     this.#records.set(origin.hostname, records)
   }
 
+  deleteRecords (origin) {
+    this.#records.delete(origin.hostname)
+  }
+
   getHandler (meta, opts) {
     return new DNSDispatchHandler(this, meta, opts)
   }
@@ -261,7 +265,7 @@ class DNSDispatchHandler extends DecoratorHandler {
         break
       }
       case 'ENOTFOUND':
-        this.#state.deleteRecord(this.#origin)
+        this.#state.deleteRecords(this.#origin)
       // eslint-disable-next-line no-fallthrough
       default:
         super.onResponseError(controller, err)
diff --git a/test/interceptors/dns.js b/test/interceptors/dns.js
index 944c190492e..1468b669d73 100644
--- a/test/interceptors/dns.js
+++ b/test/interceptors/dns.js
@@ -1732,6 +1732,68 @@ test('Should handle max cached items', async t => {
   t.equal(await response3.body.text(), 'hello world! (x2)')
 })
 
+test('Should handle ENOTFOUND response error', async t => {
+  t = tspl(t, { plan: 4 })
+  let lookupCounter = 0
+  const hostname = 'something-which-should-result-in-enotfound.undici'
+
+  const requestOptions = {
+    method: 'GET',
+    path: '/',
+    origin: 'http://localhost'
+  }
+
+  const client = new Agent().compose([
+    dispatch => {
+      return (opts, handler) => {
+        opts.origin = new URL(`http://${hostname}`)
+        return dispatch(opts, handler)
+      }
+    },
+    dns({
+      lookup (origin, opts, cb) {
+        lookupCounter++
+        if (lookupCounter === 1) {
+          cb(null, [
+            {
+              address: '127.0.0.1',
+              family: 4
+            }
+          ])
+        } else {
+          // Causes InformationalError
+          cb(null, [])
+        }
+      }
+    })
+  ])
+
+  after(async () => {
+    await client.close()
+  })
+
+  let error1
+  try {
+    await client.request(requestOptions)
+  } catch (err) {
+    error1 = err
+  }
+  t.equal(error1.code, 'ENOTFOUND')
+  t.equal(error1.hostname, hostname)
+
+  // Test that the records in the dns interceptor were deleted after the
+  // previous request
+  let error2
+  try {
+    await client.request(requestOptions)
+  } catch (err) {
+    error2 = err
+  }
+  t.equal(error2.name, 'InformationalError')
+
+  t.equal(lookupCounter, 2)
+})
+
 test('#3937 - Handle host correctly', async t => {
   t = tspl(t, { plan: 10 })
 

From 82116f0c681149fed18f59a9470b646ad565ebf3 Mon Sep 17 00:00:00 2001
From: Mathias Lundell <lundell.mathias@gmail.com>
Date: Tue, 17 Dec 2024 15:14:28 +0100
Subject: [PATCH 2/2] test: easier test

Depends on PR #3956 being merged first.
---
 test/interceptors/dns.js | 19 ++++---------------
 1 file changed, 4 insertions(+), 15 deletions(-)

diff --git a/test/interceptors/dns.js b/test/interceptors/dns.js
index 1468b669d73..050d31ee2ec 100644
--- a/test/interceptors/dns.js
+++ b/test/interceptors/dns.js
@@ -1733,9 +1733,8 @@ test('Should handle max cached items', async t => {
 })
 
 test('Should handle ENOTFOUND response error', async t => {
-  t = tspl(t, { plan: 4 })
+  t = tspl(t, { plan: 3 })
   let lookupCounter = 0
-  const hostname = 'something-which-should-result-in-enotfound.undici'
 
   const requestOptions = {
     method: 'GET',
@@ -1744,22 +1743,13 @@ test('Should handle ENOTFOUND response error', async t => {
   }
 
   const client = new Agent().compose([
-    dispatch => {
-      return (opts, handler) => {
-        opts.origin = new URL(`http://${hostname}`)
-        return dispatch(opts, handler)
-      }
-    },
     dns({
       lookup (origin, opts, cb) {
         lookupCounter++
         if (lookupCounter === 1) {
-          cb(null, [
-            {
-              address: '127.0.0.1',
-              family: 4
-            }
-          ])
+          const err = new Error('test error')
+          err.code = 'ENOTFOUND'
+          cb(err)
         } else {
           // Causes InformationalError
           cb(null, [])
@@ -1779,7 +1769,6 @@ test('Should handle ENOTFOUND response error', async t => {
     error1 = err
   }
   t.equal(error1.code, 'ENOTFOUND')
-  t.equal(error1.hostname, hostname)
 
   // Test that the records in the dns interceptor were deleted after the
   // previous request