Move sctp tests to correct directory and migrate to junit5 (#11331)

Motivation:

The sctp tests were in the incorrect directory and so were never executed. Beside this we also should use junit5

Modifications:

- Move to correct directory
- Use JUnit5 in tests

Result:

Related to https://github.com/netty/netty/issues/10757 and fixes https://github.com/netty/netty/issues/11325

transport-sctp/src/test/java/io/netty/channel/sctp/SctpLimitStreamsTest.java

@@ -22,14 +22,28 @@ import io.netty.channel.Channel;
 import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.EventLoopGroup;
-import org.junit.Test;
-import java.net.InetSocketAddress;
+import io.netty.util.SuppressForbidden;
 
-import static org.junit.Assert.*;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.Timeout;
+
+import java.net.InetSocketAddress;
+import java.util.concurrent.TimeUnit;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assumptions.assumeTrue;
 
 public abstract class SctpLimitStreamsTest {
 
-    @Test(timeout = 5000)
+    @BeforeAll
+    public static void checkSupported() {
+        assumeTrue(SctpTestUtil.isSctpSupported());
+    }
+
+    @SuppressForbidden(reason = "test-only")
+    @Test
+    @Timeout(value = 5000, unit = TimeUnit.MILLISECONDS)
     public void testSctpInitMaxstreams() throws Exception {
         EventLoopGroup loop = newEventLoopGroup();
         try {

transport-sctp/src/test/java/io/netty/channel/sctp/SctpTestUtil.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2021 The Netty Project
+ *
+ * The Netty Project licenses this file to you under the Apache License,
+ * version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at:
+ *
+ *   https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+package io.netty.channel.sctp;
+
+import com.sun.nio.sctp.SctpChannel;
+import io.netty.util.SuppressForbidden;
+
+import java.io.IOException;
+import java.nio.channels.Channel;
+
+@SuppressForbidden(reason = "test-only")
+final class SctpTestUtil {
+
+    private static final boolean SCTP_SUPPORTED;
+
+    static {
+        boolean supported = true;
+        Channel channel = null;
+        try {
+            channel = SctpChannel.open();
+        } catch (UnsupportedOperationException e) {
+            supported = false;
+        } catch (IOException e) {
+            // ignore
+        } finally {
+            if (channel != null) {
+                try {
+                    channel.close();
+                } catch (IOException ignore) {
+                    // ignore
+                }
+            }
+        }
+        SCTP_SUPPORTED = supported;
+    }
+
+    public static boolean isSctpSupported() {
+        return SCTP_SUPPORTED;
+    }
+
+    private SctpTestUtil() { }
+}

transport-sctp/src/test/java/io/netty/handler/codec/sctp/SctpMessageCompletionHandlerTest.java

@@ -21,12 +21,13 @@ import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.channel.sctp.SctpMessage;
-import org.junit.Test;
+import io.netty.util.SuppressForbidden;
+import org.junit.jupiter.api.Test;
 
 import java.net.SocketAddress;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 public class SctpMessageCompletionHandlerTest {
 
@@ -46,6 +47,7 @@ public class SctpMessageCompletionHandlerTest {
         assertEquals(0, buffer2.refCnt());
     }
 
+    @SuppressForbidden(reason = "test-only")
     private final class TestMessageInfo extends MessageInfo {
 
         private final boolean complete;