Fix: Zone SOA answer (#42)

* Fix soa zone answer

* Fix tests

Author: Meldiron

src/DNS/Zone/Resolver.php

@@ -42,6 +42,11 @@ 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 === $zone->name) {
+                return self::soaApexResponse($query, $zone);
+            }
+
             return Message::response(
                 header: $query->header,
                 responseCode: Message::RCODE_NXDOMAIN,
@@ -157,6 +162,11 @@ 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 === $zone->name) {
+                return self::soaApexResponse($query, $zone);
+            }
+
             // Path E1: Exact match of type
             $exactTypeRecords = array_filter(
                 $records,
@@ -215,6 +225,21 @@ private static function handleExactMatch(array $records, Message $query, Zone $z
         }
     }
 
+    /**
+     * Build an authoritative SOA answer for the zone apex.
+     */
+    private static function soaApexResponse(Message $query, Zone $zone): Message
+    {
+        return Message::response(
+            header: $query->header,
+            responseCode: Message::RCODE_NOERROR,
+            questions: $query->questions,
+            answers: [$zone->soa],
+            authoritative: true,
+            recursionAvailable: false
+        );
+    }
+
     /**
      * Randomize RRSet order for load balancing.
      *

tests/e2e/DNS/ClientTest.php

@@ -213,16 +213,16 @@ public function testSoaRecords(): void
         $response = $client->query(Message::query(
             new Question('appwrite.io', Record::TYPE_SOA)
         ));
-        $this->assertCount(0, $response->answers);
+        $this->assertCount(0, $response->authority);
 
-        $authority = $response->authority;
-        $this->assertCount(1, $authority);
-        $this->assertSame('appwrite.io', $authority[0]->name);
-        $this->assertSame(Record::CLASS_IN, $authority[0]->class);
-        $this->assertSame(30, $authority[0]->ttl);
-        $this->assertSame(Record::TYPE_SOA, $authority[0]->type);
+        $answers = $response->answers;
+        $this->assertCount(1, $answers);
+        $this->assertSame('appwrite.io', $answers[0]->name);
+        $this->assertSame(Record::CLASS_IN, $answers[0]->class);
+        $this->assertSame(30, $answers[0]->ttl);
+        $this->assertSame(Record::TYPE_SOA, $answers[0]->type);
 
-        $rdata = $authority[0]->rdata;
+        $rdata = $answers[0]->rdata;
         $this->assertStringContainsString('ns1.appwrite.zone', $rdata);
         $this->assertStringContainsString('team.appwrite.io', $rdata);
         $this->assertStringContainsString('1 7200 1800 1209600 3600', $rdata);

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(