From ea3950967dca7a84442388419eb26a0ac1db8fe6 Mon Sep 17 00:00:00 2001
From: Alex Potsides <alex@achingbrain.net>
Date: Wed, 13 Mar 2024 17:54:08 +0100
Subject: [PATCH] fix: stop resolving on signal abort (#2)

If the passed signal has been aborted, stop trying to resolve records.
---
 src/dns.ts         |  5 +++++
 test/index.spec.ts | 29 +++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/src/dns.ts b/src/dns.ts
index 6e03e07..c7e1f97 100644
--- a/src/dns.ts
+++ b/src/dns.ts
@@ -56,6 +56,11 @@ export class DNS implements DNSInterface {
     const errors: Error[] = []
 
     for (const resolver of resolvers) {
+      // skip further resolutions if the user aborted the signal
+      if (options.signal?.aborted === true) {
+        break
+      }
+
       try {
         const result = await resolver(domain, {
           ...options,
diff --git a/test/index.spec.ts b/test/index.spec.ts
index 6a66a2c..2f6858b 100644
--- a/test/index.spec.ts
+++ b/test/index.spec.ts
@@ -140,4 +140,33 @@ describe('dns', () => {
 
     expect(defaultResolver.callCount).to.equal(1)
   })
+
+  it('should stop resolving if the user aborts the request', async () => {
+    const error = new Error('Aborted!')
+    const controller = new AbortController()
+    const fake = (): void => {
+      controller.abort()
+
+      throw error
+    }
+    const resolvers = [
+      Sinon.stub().callsFake(fake),
+      Sinon.stub().callsFake(fake),
+      Sinon.stub().callsFake(fake)
+    ]
+
+    const resolver = dns({
+      resolvers: {
+        '.': resolvers
+      }
+    })
+    const result = resolver.query('test-abort-stops-resolving.com', {
+      signal: controller.signal
+    })
+
+    await expect(result).to.eventually.be.rejectedWith(error)
+
+    // only one resolver should have been called
+    expect(resolvers.reduce((acc, curr) => acc + curr.callCount, 0)).to.equal(1)
+  })
 })