Only run HttpTest with domain socket when it's available

src/main/java/io/vertx/core/net/impl/transport/EpollTransport.java

@@ -62,6 +62,7 @@ public static void setPendingFastOpenRequestsThreshold(int value) {
   }
 
   EpollTransport() {
+    super(true);
   }
 
   @Override

src/main/java/io/vertx/core/net/impl/transport/IOUringTransport.java

@@ -58,6 +58,10 @@ public static void setPendingFastOpenRequestsThreshold(int value) {
     pendingFastOpenRequestsThreshold = value;
   }
 
+  IOUringTransport() {
+    super(false);
+  }
+
   @Override
   public boolean supportFileRegion() {
     return false;

src/main/java/io/vertx/core/net/impl/transport/KQueueTransport.java

@@ -34,6 +34,7 @@
 class KQueueTransport extends Transport {
 
   KQueueTransport() {
+    super(true);
   }
 
   @Override

src/main/java/io/vertx/core/net/impl/transport/Transport.java

@@ -47,7 +47,7 @@ public class Transport {
   /**
    * The JDK transport, always there.
    */
-  public static Transport JDK = new Transport();
+  public static Transport JDK = new Transport(false);
 
   public boolean supportFileRegion() {
     return true;
@@ -104,7 +104,18 @@ public static Transport transport(boolean preferNative) {
     }
   }
 
+  private final boolean supportsDomainSockets;
+
   protected Transport() {
+    this(false);
+  }
+
+  protected Transport(boolean supportsDomainSockets) {
+    this.supportsDomainSockets = supportsDomainSockets;
+  }
+
+  public boolean supportsDomainSockets() {
+    return supportsDomainSockets;
   }
 
   /**

src/test/java/io/vertx/core/http/HttpTest.java

@@ -39,6 +39,7 @@
 import io.vertx.core.http.impl.ServerCookie;
 import io.vertx.core.http.impl.headers.HeadersMultiMap;
 import io.vertx.core.impl.Utils;
+import io.vertx.core.impl.VertxInternal;
 import io.vertx.core.net.NetClient;
 import io.vertx.core.net.NetClientOptions;
 import io.vertx.core.net.NetServerOptions;
@@ -176,6 +177,7 @@ public void testListenSocketAddress() {
   public void testListenDomainSocketAddress() throws Exception {
     Vertx vx = Vertx.vertx(new VertxOptions().setPreferNativeTransport(true));
     Assume.assumeTrue("Native transport must be enabled", vx.isNativeTransportEnabled());
+    Assume.assumeTrue("Transport must support domain sockets", ((VertxInternal) vx).transport().supportsDomainSockets());
     int len = 3;
     waitFor(len * len);
     List<SocketAddress> addresses = new ArrayList<>();