feat: prefix "_minecraft._tcp." if needed for SRV lookups

README.md

@@ -34,6 +34,7 @@ fetchServerInfo({
 To perform an SRV record lookup and query a Minecraft server using only a hostname, use:
 
 ```ts
+// makes an SRV lookup for _minecraft._tcp.example.com
 fetchServerInfo({
   hostname: 'example.com',
   timeout: 1000
@@ -71,6 +72,7 @@ import { fetchServerInfo } from 'minestat-es';
 (async () => {
   try {
     // query by hostname (SRV lookup)
+    // _minecraft._tcp. will be prepended unless you supply it
     const { online, error, players } = await fetchServerInfo({
       hostname: 'mc.example.com'
     });

src/index.test.ts

@@ -279,7 +279,7 @@ describe('minestat-es', () => {
     });
     test('no SRV records', async () => {
       const expectedError = new Error(
-        `No DNS records found for hostname ${hostname}`
+        `No DNS records found for hostname _minecraft._tcp.${hostname}`
       );
       const mockData: SrvRecord[] = [];
 
@@ -292,6 +292,21 @@ describe('minestat-es', () => {
         expect(error).toEqual(expectedError);
       }
     });
+    test('does not prepend _minecraft._tcp. to hostname if already present', async () => {
+      const expectedError = new Error(
+        `No DNS records found for hostname _minecraft._tcp.${hostname}`
+      );
+      const mockData: SrvRecord[] = [];
+
+      resolveMock.mockImplementation(() => Promise.resolve(mockData));
+
+      expect.assertions(1);
+      try {
+        await fetchServerInfo({ hostname: `_minecraft._tcp.${hostname}` });
+      } catch (error) {
+        expect(error).toEqual(expectedError);
+      }
+    });
     test('successful SRV lookup', async () => {
       const socket = createMockSocket(
         jest
@@ -307,7 +322,7 @@ describe('minestat-es', () => {
           )
       );
       const mockData: SrvRecord[] = [
-        { name: hostname, port, priority: 1, weight: 1 }
+        { name: `_minecraft._tcp.${hostname}`, port, priority: 1, weight: 1 }
       ];
 
       connectMock.mockImplementation(() => socket);

src/index.ts

@@ -58,12 +58,11 @@ export async function fetchServerInfo(
   // obtain address/port from DNS if required
   if ('hostname' in options) {
     const hostOptions = options as HostnameArgs;
-    const records = await dns.resolveSrv(hostOptions.hostname);
+    const mcHost = `${hostOptions.hostname.startsWith('_minecraft._tcp.') ? '' : '_minecraft._tcp.'}${hostOptions.hostname}`;
+    const records = await dns.resolveSrv(mcHost);
 
     if (!records.length) {
-      throw new Error(
-        `No DNS records found for hostname ${hostOptions.hostname}`
-      );
+      throw new Error(`No DNS records found for hostname ${mcHost}`);
     }
 
     const record = records[Math.floor(Math.random() * records.length)];