dns: add tests for ENODATA states, fix failure on main

.github/workflows/test-internet.yml

@@ -10,9 +10,13 @@ on:
     paths:
       - .github/workflows/test-internet.yml
       - test/internet/**
+      - test/common/internet.js
       - internal/dns/**
       - lib/dns.js
+      - lib/internal/dns/**
       - lib/net.js
+      - src/cares_wrap.cc
+      - src/cares_wrap.h
   push:
     branches:
       - main
@@ -22,9 +26,13 @@ on:
     paths:
       - .github/workflows/test-internet.yml
       - test/internet/**
+      - test/common/internet.js
       - internal/dns/**
       - lib/dns.js
+      - lib/internal/dns/**
       - lib/net.js
+      - src/cares_wrap.cc
+      - src/cares_wrap.h
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}

test/common/internet.js

@@ -46,6 +46,10 @@ const addresses = {
   DNS4_SERVER: '8.8.8.8',
   // An accessible IPv4 DNS server
   DNS6_SERVER: '2001:4860:4860::8888',
+  // A valid host with no records (except SOA)
+  NO_RECORD_HOST: 'void.example.com',
+  // A valid host with no TXT records, and a CNAME to a host with no TXT records
+  CNAME_TO_NO_TXT_HOST: 'www.microsoft.com',
 };
 
 for (const key of Object.keys(addresses)) {

test/internet/test-dns-txt-sigsegv.js

@@ -1,15 +1,17 @@
 'use strict';
 const common = require('../common');
+const { addresses } = require('../common/internet');
 const assert = require('assert');
 const dns = require('dns');
 const dnsPromises = dns.promises;
 
-(async function() {
-  const result = await dnsPromises.resolveTxt('www.microsoft.com');
-  assert.strictEqual(result.length, 0);
-})().then(common.mustCall());
+assert.rejects(
+  dnsPromises.resolveTxt(addresses.CNAME_TO_NO_TXT_HOST),
+  { code: 'ENODATA' },
+).then(common.mustCall());
 
-dns.resolveTxt('www.microsoft.com', common.mustCall((err, records) => {
-  assert.strictEqual(err, null);
-  assert.strictEqual(records.length, 0);
+dns.resolveTxt(addresses.CNAME_TO_NO_TXT_HOST, common.mustCall((err, records) => {
+  assert.ok(err instanceof Error);
+  assert.strictEqual(err.code, 'ENODATA');
+  assert.strictEqual(records, undefined);
 }));

test/internet/test-dns.js

@@ -724,6 +724,67 @@ test(function test_resolve_failure(done) {
 });
 
 
+async function testEmptyRecords(method, done) {
+  await assert.rejects(
+    dnsPromises[method](addresses.NO_RECORD_HOST),
+    { code: 'ENODATA' },
+  );
+
+  const req = dns[method](addresses.NO_RECORD_HOST, common.mustCall((err, result) => {
+    assert.ok(err instanceof Error);
+    assert.strictEqual(err.code, 'ENODATA');
+    assert.strictEqual(result, undefined);
+    done();
+  }));
+
+  checkWrap(req);
+}
+
+test(function test_empty_4_records(done) {
+  testEmptyRecords('resolve4', done);
+});
+
+test(function test_empty_6_records(done) {
+  testEmptyRecords('resolve6', done);
+});
+
+test(function test_empty_caa_records(done) {
+  testEmptyRecords('resolveCaa', done);
+});
+
+test(function test_empty_cname_records(done) {
+  testEmptyRecords('resolveCname', done);
+});
+
+test(function test_empty_mx_records(done) {
+  testEmptyRecords('resolveMx', done);
+});
+
+test(function test_empty_naptr_records(done) {
+  testEmptyRecords('resolveNaptr', done);
+});
+
+test(function test_empty_ns_records(done) {
+  testEmptyRecords('resolveNs', done);
+});
+
+test(function test_empty_ptr_records(done) {
+  testEmptyRecords('resolvePtr', done);
+});
+
+test(function test_empty_srv_records(done) {
+  testEmptyRecords('resolveSrv', done);
+});
+
+test(function test_empty_tlsa_records(done) {
+  testEmptyRecords('resolveTlsa', done);
+});
+
+test(function test_empty_txt_records(done) {
+  testEmptyRecords('resolveTxt', done);
+});
+
+
 let getaddrinfoCallbackCalled = false;
 
 console.log(`looking up ${addresses.INET4_HOST}..`);