Fix soa zone answer

Author: Meldiron

src/DNS/Zone/Resolver.php

@@ -42,6 +42,18 @@ public static function lookup(Message $query, Zone $zone): Message
         $records = self::selectBestRecords($query, $zone);
 
         if (empty($records)) {
+            // SOA is stored separately; if querying SOA at the zone apex, return it
+            if ($question->type === Record::TYPE_SOA && $question->name === $zone->name) {
+                return Message::response(
+                    header: $query->header,
+                    responseCode: Message::RCODE_NOERROR,
+                    questions: $query->questions,
+                    answers: [$zone->soa],
+                    authoritative: true,
+                    recursionAvailable: false
+                );
+            }
+
             return Message::response(
                 header: $query->header,
                 responseCode: Message::RCODE_NXDOMAIN,
@@ -157,6 +169,18 @@ private static function handleExactMatch(array $records, Message $query, Zone $z
         $isAuthoritative = $zone->isAuthoritative($question->name);
 
         if ($isAuthoritative) {
+            // SOA is stored separately in Zone; handle SOA queries at the zone apex
+            if ($question->type === Record::TYPE_SOA && $question->name === $zone->name) {
+                return Message::response(
+                    header: $query->header,
+                    responseCode: Message::RCODE_NOERROR,
+                    questions: $query->questions,
+                    answers: [$zone->soa],
+                    authoritative: true,
+                    recursionAvailable: false
+                );
+            }
+
             // Path E1: Exact match of type
             $exactTypeRecords = array_filter(
                 $records,

tests/unit/DNS/Zone/ResolverTest.php

@@ -465,6 +465,49 @@ public function testLookupReturnsApexAAAARecord(): void
         $this->assertSame($aaaaRecord, $response->answers[0]);
     }
 
+    public function testLookupReturnsSoaAnswerForApexSoaQueryWithRecords(): void
+    {
+        $soa = new Record(
+            'example.com',
+            Record::TYPE_SOA,
+            ttl: 300,
+            rdata: 'ns1.appwrite.zone. team@appwrite.io. 1761705275 3600 600 86400 300'
+        );
+        $aRecord = new Record('example.com', Record::TYPE_A, ttl: 3600, rdata: '1.1.1.1');
+        $zone = new Zone('example.com', [$aRecord], $soa);
+
+        $question = new Question('example.com', Record::TYPE_SOA);
+        $query = Message::query($question);
+        $response = Resolver::lookup($query, $zone);
+
+        $this->assertSame(Message::RCODE_NOERROR, $response->header->responseCode);
+        $this->assertCount(1, $response->answers);
+        $this->assertSame($soa, $response->answers[0]);
+        $this->assertTrue($response->header->authoritative);
+        $this->assertFalse($response->header->recursionAvailable);
+    }
+
+    public function testLookupReturnsSoaAnswerForApexSoaQueryWithNoRecords(): void
+    {
+        $soa = new Record(
+            'example.com',
+            Record::TYPE_SOA,
+            ttl: 300,
+            rdata: 'ns1.appwrite.zone. team@appwrite.io. 1761705275 3600 600 86400 300'
+        );
+        $zone = new Zone('example.com', [], $soa);
+
+        $question = new Question('example.com', Record::TYPE_SOA);
+        $query = Message::query($question);
+        $response = Resolver::lookup($query, $zone);
+
+        $this->assertSame(Message::RCODE_NOERROR, $response->header->responseCode);
+        $this->assertCount(1, $response->answers);
+        $this->assertSame($soa, $response->answers[0]);
+        $this->assertTrue($response->header->authoritative);
+        $this->assertFalse($response->header->recursionAvailable);
+    }
+
     public function testLookupReturnsSoaInAuthorityForApexNonNSQuery(): void
     {
         $soa = new Record(