removes junit 4 and fully migrates to junit 5

build.gradle

@@ -84,8 +84,6 @@ subprojects {
                 entry 'mockito-junit-jupiter'
                 entry 'mockito-core'
             }
-            // TODO: Remove after JUnit5 migration
-            dependency 'junit:junit:4.12'
             dependency "org.hamcrest:hamcrest-library:${ext['hamcrest.version']}"
             dependencySet(group: 'org.openjdk.jmh', version: ext['jmh.version']) {
                 entry 'jmh-core'

rsocket-core/build.gradle

@@ -40,10 +40,7 @@ dependencies {
     testRuntimeOnly 'ch.qos.logback:logback-classic'
     testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine'
 
-    // TODO: Remove after JUnit5 migration
-    testCompileOnly 'junit:junit'
     testImplementation 'org.hamcrest:hamcrest-library'
-    testRuntimeOnly 'org.junit.vintage:junit-vintage-engine'
 
     jcstressImplementation "ch.qos.logback:logback-classic"
 }

rsocket-core/src/test/java/io/rsocket/core/AbstractSocketRule.java

@@ -24,12 +24,9 @@
 import io.rsocket.test.util.TestDuplexConnection;
 import io.rsocket.test.util.TestSubscriber;
 import java.time.Duration;
-import org.junit.rules.ExternalResource;
-import org.junit.runner.Description;
-import org.junit.runners.model.Statement;
 import org.reactivestreams.Subscriber;
 
-public abstract class AbstractSocketRule<T extends RSocket> extends ExternalResource {
+public abstract class AbstractSocketRule<T extends RSocket> {
 
   protected TestDuplexConnection connection;
   protected Subscriber<Void> connectSub;
@@ -38,22 +35,15 @@ public abstract class AbstractSocketRule<T extends RSocket> extends ExternalReso
   protected int maxFrameLength = FRAME_LENGTH_MASK;
   protected int maxInboundPayloadSize = Integer.MAX_VALUE;
 
-  @Override
-  public Statement apply(final Statement base, Description description) {
-    return new Statement() {
-      @Override
-      public void evaluate() throws Throwable {
-        allocator =
-            LeaksTrackingByteBufAllocator.instrument(
-                ByteBufAllocator.DEFAULT, Duration.ofSeconds(5), "");
-        connectSub = TestSubscriber.create();
-        init();
-        base.evaluate();
-      }
-    };
+  public void init() {
+    allocator =
+        LeaksTrackingByteBufAllocator.instrument(
+            ByteBufAllocator.DEFAULT, Duration.ofSeconds(5), "");
+    connectSub = TestSubscriber.create();
+    doInit();
   }
 
-  protected void init() {
+  protected void doInit() {
     if (socket != null) {
       socket.dispose();
     }
@@ -66,12 +56,12 @@ protected void init() {
 
   public void setMaxInboundPayloadSize(int maxInboundPayloadSize) {
     this.maxInboundPayloadSize = maxInboundPayloadSize;
-    init();
+    doInit();
   }
 
   public void setMaxFrameLength(int maxFrameLength) {
     this.maxFrameLength = maxFrameLength;
-    init();
+    doInit();
   }
 
   protected abstract T newRSocket();

rsocket-core/src/test/java/io/rsocket/core/ClientServerInputMultiplexerTest.java

@@ -16,7 +16,7 @@
 
 package io.rsocket.core;
 
-import static org.junit.Assert.assertEquals;
+import static org.assertj.core.api.Assertions.assertThat;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufAllocator;
@@ -65,32 +65,32 @@ public void clientSplits() {
         .subscribe();
 
     source.addToReceivedBuffer(errorFrame(1).retain());
-    assertEquals(1, clientFrames.get());
-    assertEquals(0, serverFrames.get());
+    assertThat(clientFrames.get()).isOne();
+    assertThat(serverFrames.get()).isZero();
 
     source.addToReceivedBuffer(errorFrame(1).retain());
-    assertEquals(2, clientFrames.get());
-    assertEquals(0, serverFrames.get());
+    assertThat(clientFrames.get()).isEqualTo(2);
+    assertThat(serverFrames.get()).isZero();
 
     source.addToReceivedBuffer(leaseFrame().retain());
-    assertEquals(3, clientFrames.get());
-    assertEquals(0, serverFrames.get());
+    assertThat(clientFrames.get()).isEqualTo(3);
+    assertThat(serverFrames.get()).isZero();
 
     source.addToReceivedBuffer(keepAliveFrame().retain());
-    assertEquals(4, clientFrames.get());
-    assertEquals(0, serverFrames.get());
+    assertThat(clientFrames.get()).isEqualTo(4);
+    assertThat(serverFrames.get()).isZero();
 
     source.addToReceivedBuffer(errorFrame(2).retain());
-    assertEquals(4, clientFrames.get());
-    assertEquals(1, serverFrames.get());
+    assertThat(clientFrames.get()).isEqualTo(4);
+    assertThat(serverFrames.get()).isOne();
 
     source.addToReceivedBuffer(errorFrame(0).retain());
-    assertEquals(5, clientFrames.get());
-    assertEquals(1, serverFrames.get());
+    assertThat(clientFrames.get()).isEqualTo(5);
+    assertThat(serverFrames.get()).isOne();
 
     source.addToReceivedBuffer(metadataPushFrame().retain());
-    assertEquals(5, clientFrames.get());
-    assertEquals(2, serverFrames.get());
+    assertThat(clientFrames.get()).isEqualTo(5);
+    assertThat(serverFrames.get()).isEqualTo(2);
   }
 
   @Test
@@ -110,32 +110,32 @@ public void serverSplits() {
         .subscribe();
 
     source.addToReceivedBuffer(errorFrame(1).retain());
-    assertEquals(1, clientFrames.get());
-    assertEquals(0, serverFrames.get());
+    assertThat(clientFrames.get()).isEqualTo(1);
+    assertThat(serverFrames.get()).isZero();
 
     source.addToReceivedBuffer(errorFrame(1).retain());
-    assertEquals(2, clientFrames.get());
-    assertEquals(0, serverFrames.get());
+    assertThat(clientFrames.get()).isEqualTo(2);
+    assertThat(serverFrames.get()).isZero();
 
     source.addToReceivedBuffer(leaseFrame().retain());
-    assertEquals(2, clientFrames.get());
-    assertEquals(1, serverFrames.get());
+    assertThat(clientFrames.get()).isEqualTo(2);
+    assertThat(serverFrames.get()).isOne();
 
     source.addToReceivedBuffer(keepAliveFrame().retain());
-    assertEquals(2, clientFrames.get());
-    assertEquals(2, serverFrames.get());
+    assertThat(clientFrames.get()).isEqualTo(2);
+    assertThat(serverFrames.get()).isEqualTo(2);
 
     source.addToReceivedBuffer(errorFrame(2).retain());
-    assertEquals(2, clientFrames.get());
-    assertEquals(3, serverFrames.get());
+    assertThat(clientFrames.get()).isEqualTo(2);
+    assertThat(serverFrames.get()).isEqualTo(3);
 
     source.addToReceivedBuffer(errorFrame(0).retain());
-    assertEquals(2, clientFrames.get());
-    assertEquals(4, serverFrames.get());
+    assertThat(clientFrames.get()).isEqualTo(2);
+    assertThat(serverFrames.get()).isEqualTo(4);
 
     source.addToReceivedBuffer(metadataPushFrame().retain());
-    assertEquals(3, clientFrames.get());
-    assertEquals(4, serverFrames.get());
+    assertThat(clientFrames.get()).isEqualTo(3);
+    assertThat(serverFrames.get()).isEqualTo(4);
   }
 
   private ByteBuf leaseFrame() {

rsocket-core/src/test/java/io/rsocket/core/DefaultRSocketClientTests.java

@@ -15,11 +15,6 @@
  * limitations under the License.
  */
 
-import static io.rsocket.frame.FrameHeaderCodec.frameType;
-import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.Matchers.greaterThanOrEqualTo;
-import static org.hamcrest.Matchers.hasSize;
-
 import io.netty.buffer.ByteBuf;
 import io.netty.util.CharsetUtil;
 import io.netty.util.ReferenceCountUtil;
@@ -37,7 +32,6 @@
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.List;
 import java.util.Map;
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -52,7 +46,6 @@
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
-import org.junit.runners.model.Statement;
 import org.reactivestreams.Publisher;
 import reactor.core.Disposable;
 import reactor.core.publisher.Flux;
@@ -64,6 +57,7 @@
 import reactor.test.publisher.TestPublisher;
 import reactor.test.util.RaceTestUtils;
 import reactor.util.context.Context;
+import reactor.util.context.ContextView;
 import reactor.util.retry.Retry;
 
 public class DefaultRSocketClientTests {
@@ -75,13 +69,7 @@ public void setUp() throws Throwable {
     Hooks.onNextDropped(ReferenceCountUtil::safeRelease);
     Hooks.onErrorDropped((t) -> {});
     rule = new ClientSocketRule();
-    rule.apply(
-            new Statement() {
-              @Override
-              public void evaluate() {}
-            },
-            null)
-        .evaluate();
+    rule.init();
   }
 
   @AfterEach
@@ -179,19 +167,12 @@ public void shouldSentFrameOnResolution(
   @MethodSource("interactions")
   @SuppressWarnings({"unchecked", "rawtypes"})
   public void shouldHaveNoLeaksOnPayloadInCaseOfRacingOfOnNextAndCancel(
-      BiFunction<RSocketClient, Publisher<Payload>, Publisher<?>> request, FrameType requestType)
-      throws Throwable {
+      BiFunction<RSocketClient, Publisher<Payload>, Publisher<?>> request, FrameType requestType) {
     Assumptions.assumeThat(requestType).isNotEqualTo(FrameType.REQUEST_CHANNEL);
 
     for (int i = 0; i < RaceTestConstants.REPEATS; i++) {
       ClientSocketRule rule = new ClientSocketRule();
-      rule.apply(
-              new Statement() {
-                @Override
-                public void evaluate() {}
-              },
-              null)
-          .evaluate();
+      rule.init();
       Payload payload = ByteBufPayload.create("test", "testMetadata");
       TestPublisher<Payload> testPublisher =
           TestPublisher.createNoncompliant(TestPublisher.Violation.DEFER_CANCELLATION);
@@ -241,19 +222,12 @@ public void evaluate() {}
   @MethodSource("interactions")
   @SuppressWarnings({"unchecked", "rawtypes"})
   public void shouldHaveNoLeaksOnPayloadInCaseOfRacingOfRequestAndCancel(
-      BiFunction<RSocketClient, Publisher<Payload>, Publisher<?>> request, FrameType requestType)
-      throws Throwable {
+      BiFunction<RSocketClient, Publisher<Payload>, Publisher<?>> request, FrameType requestType) {
     Assumptions.assumeThat(requestType).isNotEqualTo(FrameType.REQUEST_CHANNEL);
 
     for (int i = 0; i < RaceTestConstants.REPEATS; i++) {
       ClientSocketRule rule = new ClientSocketRule();
-      rule.apply(
-              new Statement() {
-                @Override
-                public void evaluate() {}
-              },
-              null)
-          .evaluate();
+      rule.init();
       ByteBuf dataBuffer = rule.allocator.buffer();
       dataBuffer.writeCharSequence("test", CharsetUtil.UTF_8);
 
@@ -311,14 +285,17 @@ public void shouldPropagateDownstreamContext(
     Payload payload = ByteBufPayload.create(dataBuffer, metadataBuffer);
     AssertSubscriber assertSubscriber = new AssertSubscriber(Context.of("test", "test"));
 
-    Context[] receivedContext = new Context[1];
+    ContextView[] receivedContext = new Context[1];
     Publisher<?> publisher =
         request.apply(
             rule.client,
             Mono.just(payload)
                 .mergeWith(
-                    Mono.subscriberContext()
-                        .doOnNext(c -> receivedContext[0] = c)
+                    Mono.deferContextual(
+                            c -> {
+                              receivedContext[0] = c;
+                              return Mono.empty();
+                            })
                         .then(Mono.empty())));
     publisher.subscribe(assertSubscriber);
 
@@ -481,16 +458,11 @@ public void shouldDisposeOriginalSource() {
   }
 
   @Test
-  public void shouldDisposeOriginalSourceIfRacing() throws Throwable {
+  public void shouldDisposeOriginalSourceIfRacing() {
     for (int i = 0; i < RaceTestConstants.REPEATS; i++) {
       ClientSocketRule rule = new ClientSocketRule();
-      rule.apply(
-              new Statement() {
-                @Override
-                public void evaluate() {}
-              },
-              null)
-          .evaluate();
+
+      rule.init();
 
       AssertSubscriber<RSocket> assertSubscriber = AssertSubscriber.create();
       rule.client.source().subscribe(assertSubscriber);
@@ -520,8 +492,8 @@ public static class ClientSocketRule extends AbstractSocketRule<RSocketRequester
     protected Sinks.One<RSocket> producer;
 
     @Override
-    protected void init() {
-      super.init();
+    protected void doInit() {
+      super.doInit();
       delayer = () -> producer.tryEmitValue(socket);
       producer = Sinks.one();
       client =
@@ -547,22 +519,5 @@ protected RSocketRequester newRSocket() {
           __ -> null,
           null);
     }
-
-    public int getStreamIdForRequestType(FrameType expectedFrameType) {
-      assertThat("Unexpected frames sent.", connection.getSent(), hasSize(greaterThanOrEqualTo(1)));
-      List<FrameType> framesFound = new ArrayList<>();
-      for (ByteBuf frame : connection.getSent()) {
-        FrameType frameType = frameType(frame);
-        if (frameType == expectedFrameType) {
-          return FrameHeaderCodec.streamId(frame);
-        }
-        framesFound.add(frameType);
-      }
-      throw new AssertionError(
-          "No frames sent with frame type: "
-              + expectedFrameType
-              + ", frames found: "
-              + framesFound);
-    }
   }
 }