Upgrade prober & proxy packages from JUnit 4 to JUnit 5 (#734)

* Upgrade prober & proxy packages from JUnit 4 to JUnit 5

prober/build.gradle

@@ -48,10 +48,9 @@ dependencies {
 
     testCompile deps['com.google.monitoring-client:contrib']
     testCompile deps['com.google.truth:truth']
-    testCompile deps['junit:junit']
     testCompile deps['org.junit.jupiter:junit-jupiter-api']
     testCompile deps['org.junit.jupiter:junit-jupiter-engine']
-    testCompile deps['org.junit.vintage:junit-vintage-engine']
+    testCompile deps['org.junit.jupiter:junit-jupiter-params']
     testCompile deps['org.mockito:mockito-core']
     testCompile project(path: ':common', configuration: 'testing')
     testCompile project(path: ':networking', configuration: 'testRuntime')

prober/gradle/dependency-locks/testCompile.lockfile

@@ -47,7 +47,7 @@ javax.inject:javax.inject:1
 javax.mail:mail:1.4
 javax.xml.bind:jaxb-api:2.3.0
 joda-time:joda-time:2.9.2
-junit:junit:4.13
+junit:junit:4.12
 net.bytebuddy:byte-buddy-agent:1.10.5
 net.bytebuddy:byte-buddy:1.10.5
 org.apache.httpcomponents:httpclient:4.5.11
@@ -63,7 +63,6 @@ org.junit.jupiter:junit-jupiter-engine:5.6.2
 org.junit.jupiter:junit-jupiter-params:5.6.2
 org.junit.platform:junit-platform-commons:1.6.2
 org.junit.platform:junit-platform-engine:1.6.2
-org.junit.vintage:junit-vintage-engine:5.6.2
 org.junit:junit-bom:5.6.2
 org.mockito:mockito-core:3.3.3
 org.objenesis:objenesis:2.6

prober/gradle/dependency-locks/testCompileClasspath.lockfile

@@ -47,7 +47,7 @@ javax.inject:javax.inject:1
 javax.mail:mail:1.4
 javax.xml.bind:jaxb-api:2.3.0
 joda-time:joda-time:2.9.2
-junit:junit:4.13
+junit:junit:4.12
 net.bytebuddy:byte-buddy-agent:1.10.5
 net.bytebuddy:byte-buddy:1.10.5
 org.apache.httpcomponents:httpclient:4.5.11
@@ -63,7 +63,6 @@ org.junit.jupiter:junit-jupiter-engine:5.6.2
 org.junit.jupiter:junit-jupiter-params:5.6.2
 org.junit.platform:junit-platform-commons:1.6.2
 org.junit.platform:junit-platform-engine:1.6.2
-org.junit.vintage:junit-vintage-engine:5.6.2
 org.junit:junit-bom:5.6.2
 org.mockito:mockito-core:3.3.3
 org.objenesis:objenesis:2.6

prober/gradle/dependency-locks/testRuntime.lockfile

@@ -47,7 +47,7 @@ javax.inject:javax.inject:1
 javax.mail:mail:1.4
 javax.xml.bind:jaxb-api:2.3.0
 joda-time:joda-time:2.9.2
-junit:junit:4.13
+junit:junit:4.12
 net.bytebuddy:byte-buddy-agent:1.10.5
 net.bytebuddy:byte-buddy:1.10.5
 org.apache.httpcomponents:httpclient:4.5.11
@@ -63,7 +63,6 @@ org.junit.jupiter:junit-jupiter-engine:5.6.2
 org.junit.jupiter:junit-jupiter-params:5.6.2
 org.junit.platform:junit-platform-commons:1.6.2
 org.junit.platform:junit-platform-engine:1.6.2
-org.junit.vintage:junit-vintage-engine:5.6.2
 org.junit:junit-bom:5.6.2
 org.mockito:mockito-core:3.3.3
 org.objenesis:objenesis:2.6

prober/gradle/dependency-locks/testRuntimeClasspath.lockfile

@@ -47,7 +47,7 @@ javax.inject:javax.inject:1
 javax.mail:mail:1.4
 javax.xml.bind:jaxb-api:2.3.0
 joda-time:joda-time:2.9.2
-junit:junit:4.13
+junit:junit:4.12
 net.bytebuddy:byte-buddy-agent:1.10.5
 net.bytebuddy:byte-buddy:1.10.5
 org.apache.httpcomponents:httpclient:4.5.11
@@ -63,7 +63,6 @@ org.junit.jupiter:junit-jupiter-engine:5.6.2
 org.junit.jupiter:junit-jupiter-params:5.6.2
 org.junit.platform:junit-platform-commons:1.6.2
 org.junit.platform:junit-platform-engine:1.6.2
-org.junit.vintage:junit-vintage-engine:5.6.2
 org.junit:junit-bom:5.6.2
 org.mockito:mockito-core:3.3.3
 org.objenesis:objenesis:2.6

prober/src/main/java/google/registry/monitoring/blackbox/message/EppMessage.java

@@ -92,12 +92,14 @@ public class EppMessage {
   @VisibleForTesting
   public static final String XPASS_EXPRESSION =
       String.format("//eppns:result[@code>='%s'][@code<'%s']", 1000, 2000);
+
   /**
    * Expression that expresses a result code in the {@link EppResponseMessage} that means failure.
    */
   @VisibleForTesting
   public static final String XFAIL_EXPRESSION =
       String.format("//eppns:result[@code>='%s'][@code<'%s']", 2000, 3000);
+
   // "Security" errors from RFC 5730, plus the error we get when we end
   // up no longer logged (see b/28196510).
   // 2002    "Command use error"

prober/src/test/java/google/registry/monitoring/blackbox/ProbingSequenceTest.java

@@ -37,10 +37,8 @@ import io.netty.channel.Channel;
 import io.netty.channel.ChannelPromise;
 import io.netty.channel.embedded.EmbeddedChannel;
 import org.joda.time.Duration;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 import org.mockito.Mockito;
 
 /**
@@ -56,8 +54,7 @@ import org.mockito.Mockito;
  * UnrecoverableStateException}, using mocks of the steps or actions, as the sequences are run using
  * the main thread (with {@link EmbeddedChannel}).
  */
-@RunWith(JUnit4.class)
-public class ProbingSequenceTest {
+class ProbingSequenceTest {
 
   private static final String PROTOCOL_NAME = "PROTOCOL";
   private static final String MESSAGE_NAME = "MESSAGE";
@@ -100,8 +97,8 @@ public class ProbingSequenceTest {
   /** Default mock {@link Clock} passed into each {@link ProbingSequence} tested */
   private Clock clock = new FakeClock();
 
-  @Before
-  public void setup() {
+  @BeforeEach
+  void beforeEach() {
     // To avoid a NullPointerException, we must have a protocol return persistent connection as
     // false.
     doReturn(true).when(mockProtocol).persistentConnection();
@@ -124,7 +121,7 @@ public class ProbingSequenceTest {
   }
 
   @Test
-  public void testSequenceBasicConstruction_Success() {
+  void testSequenceBasicConstruction_Success() {
     ProbingStep firstStep = Mockito.mock(ProbingStep.class);
     ProbingStep secondStep = Mockito.mock(ProbingStep.class);
     ProbingStep thirdStep = Mockito.mock(ProbingStep.class);
@@ -149,7 +146,7 @@ public class ProbingSequenceTest {
   }
 
   @Test
-  public void testSequenceAdvancedConstruction_Success() {
+  void testSequenceAdvancedConstruction_Success() {
     ProbingStep firstStep = Mockito.mock(ProbingStep.class);
     ProbingStep secondStep = Mockito.mock(ProbingStep.class);
     ProbingStep thirdStep = Mockito.mock(ProbingStep.class);
@@ -175,7 +172,7 @@ public class ProbingSequenceTest {
   }
 
   @Test
-  public void testRunStep_Success() throws UndeterminedStateException {
+  void testRunStep_Success() throws UndeterminedStateException {
     // Always returns a succeeded future on call to mockAction. Also advances the FakeClock by
     // standard LATENCY to check right latency is recorded.
     doAnswer(
@@ -229,7 +226,7 @@ public class ProbingSequenceTest {
   }
 
   @Test
-  public void testRunLoop_Success() throws UndeterminedStateException {
+  void testRunLoop_Success() throws UndeterminedStateException {
     // Always returns a succeeded future on call to mockAction. Also advances the FakeClock by
     // standard LATENCY to check right latency is recorded.
     doAnswer(
@@ -367,7 +364,7 @@ public class ProbingSequenceTest {
   }
 
   @Test
-  public void testRunStep_FailureRunning() throws UndeterminedStateException {
+  void testRunStep_FailureRunning() throws UndeterminedStateException {
     // Returns a failed future when calling the generated mock action. Also advances FakeClock by
     // LATENCY in order to check right latency is recorded.
     doAnswer(
@@ -402,7 +399,7 @@ public class ProbingSequenceTest {
   }
 
   @Test
-  public void testRunStep_FailureGenerating() throws UndeterminedStateException {
+  void testRunStep_FailureGenerating() throws UndeterminedStateException {
     // Mock first step throws an error when generating the first action, and advances the clock
     // by LATENCY.
     doAnswer(

prober/src/test/java/google/registry/monitoring/blackbox/handler/EppActionHandlerTest.java

@@ -17,24 +17,18 @@ package google.registry.monitoring.blackbox.handler;
 import static com.google.common.truth.Truth.assertThat;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
-import google.registry.monitoring.blackbox.exception.EppClientException;
 import google.registry.monitoring.blackbox.exception.FailureException;
-import google.registry.monitoring.blackbox.exception.UndeterminedStateException;
 import google.registry.monitoring.blackbox.message.EppRequestMessage;
 import google.registry.monitoring.blackbox.message.EppResponseMessage;
 import google.registry.monitoring.blackbox.util.EppUtils;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.embedded.EmbeddedChannel;
-import java.io.IOException;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.Parameterized;
-import org.junit.runners.Parameterized.Parameter;
-import org.junit.runners.Parameterized.Parameters;
+import java.util.stream.Stream;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
 import org.w3c.dom.Document;
-import org.xml.sax.SAXException;
 
 /**
  * Unit tests for {@link EppActionHandler} and {@link EppMessageHandler} as well as integration
@@ -44,8 +38,7 @@ import org.xml.sax.SAXException;
  * of {@link EppResponseMessage}s with corresponding {@link EppRequestMessage} sent down channel
  * pipeline.
  */
-@RunWith(Parameterized.class)
-public class EppActionHandlerTest {
+class EppActionHandlerTest {
 
   private static final String USER_ID = "TEST_ID";
   private static final String USER_PASSWORD = "TEST_PASSWORD";
@@ -54,94 +47,74 @@ public class EppActionHandlerTest {
   private static final String DOMAIN_NAME = "TEST_DOMAIN_NAME.test";
   private static final String SERVER_ID = "TEST_SERVER_ID";
 
-  @Parameter(0)
-  public EppRequestMessage message;
-
   private EmbeddedChannel channel;
   private EppActionHandler actionHandler = new EppActionHandler();
   private EppMessageHandler messageHandler = new EppMessageHandler(EppUtils.getGreetingResponse());
 
-  // We test all relevant EPP actions
-  @Parameters(name = "{0}")
-  public static EppRequestMessage[] data() {
-    return new EppRequestMessage[] {
-      EppUtils.getHelloMessage(EppUtils.getGreetingResponse()),
-      EppUtils.getLoginMessage(EppUtils.getSuccessResponse(), USER_ID, USER_PASSWORD),
-      EppUtils.getCreateMessage(EppUtils.getSuccessResponse()),
-      EppUtils.getCreateMessage(EppUtils.getFailureResponse()),
-      EppUtils.getDeleteMessage(EppUtils.getSuccessResponse()),
-      EppUtils.getDeleteMessage(EppUtils.getFailureResponse()),
-      EppUtils.getLogoutMessage(EppUtils.getSuccessResponse()),
-      EppUtils.getCheckMessage(EppUtils.getDomainExistsResponse()),
-      EppUtils.getCheckMessage(EppUtils.getDomainNotExistsResponse())
-    };
+  @SuppressWarnings("unused")
+  static Stream<Arguments> provideTestCombinations() {
+    return Stream.of(
+            EppUtils.getHelloMessage(EppUtils.getGreetingResponse()),
+            EppUtils.getLoginMessage(EppUtils.getSuccessResponse(), USER_ID, USER_PASSWORD),
+            EppUtils.getCreateMessage(EppUtils.getSuccessResponse()),
+            EppUtils.getCreateMessage(EppUtils.getFailureResponse()),
+            EppUtils.getDeleteMessage(EppUtils.getSuccessResponse()),
+            EppUtils.getDeleteMessage(EppUtils.getFailureResponse()),
+            EppUtils.getLogoutMessage(EppUtils.getSuccessResponse()),
+            EppUtils.getCheckMessage(EppUtils.getDomainExistsResponse()),
+            EppUtils.getCheckMessage(EppUtils.getDomainNotExistsResponse()))
+        .map(Arguments::of);
   }
 
-  /** Setup main three handlers to be used in pipeline. */
-  @Before
-  public void setup() throws EppClientException {
+  private void setupRequestAndChannels(EppRequestMessage message, ChannelHandler... handlers)
+      throws Exception {
     message.modifyMessage(USER_CLIENT_TRID, DOMAIN_NAME);
-  }
-
-  private void setupEmbeddedChannel(ChannelHandler... handlers) {
     channel = new EmbeddedChannel(handlers);
   }
 
   private Document getResponse(EppResponseMessage response, boolean fail, String clTrid)
-      throws IOException, EppClientException {
-    if (response.name().equals("greeting")) {
-      if (fail) {
-        return EppUtils.getBasicResponse(true, clTrid, SERVER_ID);
-      } else {
-        return EppUtils.getGreeting();
-      }
-    } else if (response.name().equals("domainExists")) {
-      return EppUtils.getDomainCheck(!fail, clTrid, SERVER_ID, DOMAIN_NAME);
-
-    } else if (response.name().equals("domainNotExists")) {
-      return EppUtils.getDomainCheck(fail, clTrid, SERVER_ID, DOMAIN_NAME);
-
-    } else if (response.name().equals("success")) {
-      return EppUtils.getBasicResponse(!fail, clTrid, SERVER_ID);
-
-    } else {
-      return EppUtils.getBasicResponse(fail, clTrid, SERVER_ID);
+      throws Exception {
+    switch (response.name()) {
+      case "greeting":
+        if (fail) {
+          return EppUtils.getBasicResponse(true, clTrid, SERVER_ID);
+        } else {
+          return EppUtils.getGreeting();
+        }
+      case "domainExists":
+        return EppUtils.getDomainCheck(!fail, clTrid, SERVER_ID, DOMAIN_NAME);
+      case "domainNotExists":
+        return EppUtils.getDomainCheck(fail, clTrid, SERVER_ID, DOMAIN_NAME);
+      case "success":
+        return EppUtils.getBasicResponse(!fail, clTrid, SERVER_ID);
+      default:
+        return EppUtils.getBasicResponse(fail, clTrid, SERVER_ID);
     }
   }
 
-  @Test
-  public void testBasicAction_Success_Embedded()
-      throws SAXException, IOException, EppClientException, FailureException {
+  @ParameterizedTest
+  @MethodSource("provideTestCombinations")
+  void testBasicAction_Success_Embedded(EppRequestMessage message) throws Exception {
     // We simply use an embedded channel in this instance
-    setupEmbeddedChannel(actionHandler);
-
+    setupRequestAndChannels(message, actionHandler);
     ChannelFuture future = actionHandler.getFinishedFuture();
-
     EppResponseMessage response = message.getExpectedResponse();
-
     response.getDocument(
         EppUtils.docToByteBuf(getResponse(message.getExpectedResponse(), false, USER_CLIENT_TRID)));
-
     channel.writeInbound(response);
-
     ChannelFuture unusedFuture = future.syncUninterruptibly();
-
     assertThat(future.isSuccess()).isTrue();
   }
 
-  @Test
-  public void testBasicAction_FailCode_Embedded()
-      throws SAXException, IOException, EppClientException, FailureException {
+  @ParameterizedTest
+  @MethodSource("provideTestCombinations")
+  void testBasicAction_FailCode_Embedded(EppRequestMessage message) throws Exception {
     // We simply use an embedded channel in this instance
-    setupEmbeddedChannel(actionHandler);
-
+    setupRequestAndChannels(message, actionHandler);
     ChannelFuture future = actionHandler.getFinishedFuture();
-
     EppResponseMessage response = message.getExpectedResponse();
-
     response.getDocument(
         EppUtils.docToByteBuf(getResponse(message.getExpectedResponse(), true, USER_CLIENT_TRID)));
-
     channel.writeInbound(response);
 
     assertThrows(
@@ -151,19 +124,15 @@ public class EppActionHandlerTest {
         });
   }
 
-  @Test
-  public void testBasicAction_FailTRID_Embedded()
-      throws SAXException, IOException, EppClientException, FailureException {
+  @ParameterizedTest
+  @MethodSource("provideTestCombinations")
+  void testBasicAction_FailTRID_Embedded(EppRequestMessage message) throws Exception {
     // We simply use an embedded channel in this instance
-    setupEmbeddedChannel(actionHandler);
-
+    setupRequestAndChannels(message, actionHandler);
     ChannelFuture future = actionHandler.getFinishedFuture();
-
     EppResponseMessage response = message.getExpectedResponse();
-
     response.getDocument(
         EppUtils.docToByteBuf(getResponse(message.getExpectedResponse(), false, FAILURE_TRID)));
-
     channel.writeInbound(response);
 
     if (message.getExpectedResponse().name().equals("greeting")) {
@@ -178,32 +147,26 @@ public class EppActionHandlerTest {
     }
   }
 
-  @Test
-  public void testIntegratedAction_Success_Embedded()
-      throws IOException, SAXException, UndeterminedStateException {
+  @ParameterizedTest
+  @MethodSource("provideTestCombinations")
+  void testIntegratedAction_Success_Embedded(EppRequestMessage message) throws Exception {
     // We simply use an embedded channel in this instance
-    setupEmbeddedChannel(messageHandler, actionHandler);
-
+    setupRequestAndChannels(message, messageHandler, actionHandler);
     ChannelFuture future = actionHandler.getFinishedFuture();
     channel.writeOutbound(message);
-
     channel.writeInbound(
         EppUtils.docToByteBuf(getResponse(message.getExpectedResponse(), false, USER_CLIENT_TRID)));
-
     ChannelFuture unusedFuture = future.syncUninterruptibly();
-
     assertThat(future.isSuccess()).isTrue();
   }
 
-  @Test
-  public void testIntegratedAction_FailCode_Embedded()
-      throws IOException, SAXException, UndeterminedStateException {
+  @ParameterizedTest
+  @MethodSource("provideTestCombinations")
+  void testIntegratedAction_FailCode_Embedded(EppRequestMessage message) throws Exception {
     // We simply use an embedded channel in this instance
-    setupEmbeddedChannel(messageHandler, actionHandler);
-
+    setupRequestAndChannels(message, messageHandler, actionHandler);
     ChannelFuture future = actionHandler.getFinishedFuture();
     channel.writeOutbound(message);
-
     channel.writeInbound(
         EppUtils.docToByteBuf(getResponse(message.getExpectedResponse(), true, USER_CLIENT_TRID)));
 
@@ -214,15 +177,13 @@ public class EppActionHandlerTest {
         });
   }
 
-  @Test
-  public void testIntegratedAction_FailTRID_Embedded()
-      throws IOException, SAXException, UndeterminedStateException {
+  @ParameterizedTest
+  @MethodSource("provideTestCombinations")
+  void testIntegratedAction_FailTRID_Embedded(EppRequestMessage message) throws Exception {
     // We simply use an embedded channel in this instance
-    setupEmbeddedChannel(messageHandler, actionHandler);
-
+    setupRequestAndChannels(message, messageHandler, actionHandler);
     ChannelFuture future = actionHandler.getFinishedFuture();
     channel.writeOutbound(message);
-
     channel.writeInbound(
         EppUtils.docToByteBuf(getResponse(message.getExpectedResponse(), false, FAILURE_TRID)));
 

prober/src/test/java/google/registry/monitoring/blackbox/handler/WebWhoisActionHandlerTest.java

@@ -38,9 +38,7 @@ import io.netty.channel.nio.NioEventLoopGroup;
 import io.netty.handler.codec.http.FullHttpResponse;
 import io.netty.handler.codec.http.HttpResponseStatus;
 import javax.inject.Provider;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
+import org.junit.jupiter.api.Test;
 
 /**
  * Unit tests for {@link WebWhoisActionHandler}.
@@ -48,8 +46,7 @@ import org.junit.runners.JUnit4;
  * <p>Attempts to test how well {@link WebWhoisActionHandler} works when responding to all possible
  * types of responses
  */
-@RunWith(JUnit4.class)
-public class WebWhoisActionHandlerTest {
+class WebWhoisActionHandlerTest {
 
   private static final int HTTP_PORT = 80;
   private static final String HTTP_REDIRECT = "http://";
@@ -105,7 +102,7 @@ public class WebWhoisActionHandlerTest {
   }
 
   @Test
-  public void testBasic_responseOk() {
+  void testBasic_responseOk() {
     // setup
     setup("", null, true);
     setupChannel(initialProtocol);
@@ -126,7 +123,7 @@ public class WebWhoisActionHandlerTest {
   }
 
   @Test
-  public void testBasic_responseFailure_badRequest() {
+  void testBasic_responseFailure_badRequest() {
     // setup
     setup("", null, false);
     setupChannel(initialProtocol);
@@ -152,7 +149,7 @@ public class WebWhoisActionHandlerTest {
   }
 
   @Test
-  public void testBasic_responseFailure_badURL() {
+  void testBasic_responseFailure_badURL() {
     // setup
     setup("", null, false);
     setupChannel(initialProtocol);
@@ -179,7 +176,7 @@ public class WebWhoisActionHandlerTest {
   }
 
   @Test
-  public void testAdvanced_redirect() {
+  void testAdvanced_redirect() {
     // Sets up EventLoopGroup with 1 thread to be blocking.
     EventLoopGroup group = new NioEventLoopGroup(1);
 

prober/src/test/java/google/registry/monitoring/blackbox/message/EppMessageTest.java

@@ -29,23 +29,21 @@ import java.util.List;
 import java.util.Map;
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.xml.sax.SAXException;
 
-@RunWith(JUnit4.class)
-public class EppMessageTest {
+/** Unit tests for {@link EppMessage}. */
+class EppMessageTest {
 
   private Document xmlDoc = null;
   private Document greeting = null;
   private DocumentBuilder builder = null;
 
-  @Before
-  public void setUp() throws Exception {
+  @BeforeEach
+  void beforeEach() throws Exception {
     String xmlString =
         "<epp>"
             + "<textAndAttr myAttr1='1'>text1</textAndAttr>"
@@ -64,7 +62,7 @@ public class EppMessageTest {
   }
 
   @Test
-  public void xmlDocToStringSuccess() throws Exception {
+  void xmlDocToStringSuccess() throws Exception {
     Document xml = builder.newDocument();
     Element doc = xml.createElement("doc");
     Element title = xml.createElement("title");
@@ -88,7 +86,7 @@ public class EppMessageTest {
   }
 
   @Test
-  public void xmlDoctoByteArraySuccess() throws Exception {
+  void xmlDoctoByteArraySuccess() throws Exception {
     Document xml = builder.newDocument();
     Element doc = xml.createElement("doc");
     Element title = xml.createElement("title");
@@ -112,12 +110,12 @@ public class EppMessageTest {
   }
 
   @Test
-  public void eppValidateSuccess() throws Exception {
+  void eppValidateSuccess() throws Exception {
     EppMessage.eppValidate(greeting);
   }
 
   @Test
-  public void eppValidateFail() {
+  void eppValidateFail() {
     assertThrows(SAXException.class, () -> EppMessage.eppValidate(xmlDoc));
   }
 
@@ -127,7 +125,7 @@ public class EppMessageTest {
    * actual (greeting) respoonse.
    */
   @Test
-  public void verifyResponseSuccess() throws Exception {
+  void verifyResponseSuccess() throws Exception {
     ArrayList<String> list = new ArrayList<>();
     list.add("epp");
     list.add("//textAndAttr[@myAttr1='1'] | //textAndAttr[child::text()='text1']");
@@ -139,7 +137,7 @@ public class EppMessageTest {
   }
 
   @Test
-  public void verifyEppResponseSuccess() throws Exception {
+  void verifyEppResponseSuccess() throws Exception {
     ArrayList<String> list = new ArrayList<>();
     list.add("*");
     list.add("/eppns:epp");
@@ -151,7 +149,7 @@ public class EppMessageTest {
   }
 
   @Test
-  public void verifyResponseMissingTextFail() {
+  void verifyResponseMissingTextFail() {
     ArrayList<String> list = new ArrayList<>();
     list.add("epp");
     list.add("//textAndAttr[child::text()='text2']");
@@ -160,7 +158,7 @@ public class EppMessageTest {
   }
 
   @Test
-  public void verifyResponseMissingAttrFail() {
+  void verifyResponseMissingAttrFail() {
     ArrayList<String> list = new ArrayList<>();
     list.add("epp");
     list.add("//textAndAttr/@myAttr2");
@@ -169,7 +167,7 @@ public class EppMessageTest {
   }
 
   @Test
-  public void verifyResponseSplitTextAttrFail() {
+  void verifyResponseSplitTextAttrFail() {
     ArrayList<String> list = new ArrayList<>();
     list.add("epp");
     list.add("//textAndAttrSplitRepeated[@myAttr3='3'][child::text()='text3']");
@@ -178,7 +176,7 @@ public class EppMessageTest {
   }
 
   @Test
-  public void getEppDocFromTemplateTest() throws Exception {
+  void getEppDocFromTemplateTest() throws Exception {
     Map<String, String> replaceMap = new HashMap<>();
     replaceMap.put("//eppns:expectedClTRID", "ABC-1234-CBA");
     replaceMap.put("//domainns:name", "foo");
@@ -189,7 +187,7 @@ public class EppMessageTest {
   }
 
   @Test
-  public void getEppDocFromTemplateTestFail() {
+  void getEppDocFromTemplateTestFail() {
     Map<String, String> replaceMap = new HashMap<>();
     replaceMap.put("//eppns:create", "ABC-1234-CBA");
     replaceMap.put("//domainns:name", "foo");
@@ -199,7 +197,7 @@ public class EppMessageTest {
   }
 
   @Test
-  public void checkValidDomainName() {
+  void checkValidDomainName() {
     String domainName = "good.tld";
     assertThat(domainName.matches(EppMessage.VALID_SLD_LABEL_REGEX)).isTrue();
     domainName = "good.tld.";

prober/src/test/java/google/registry/monitoring/blackbox/metric/MetricsCollectorTest.java

@@ -19,14 +19,11 @@ import static com.google.monitoring.metrics.contrib.LongMetricSubject.assertThat
 
 import com.google.common.collect.ImmutableSet;
 import google.registry.monitoring.blackbox.metric.MetricsCollector.ResponseType;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 
 /** Unit tests for {@link MetricsCollector}. */
-@RunWith(JUnit4.class)
-public class MetricsCollectorTest {
+class MetricsCollectorTest {
 
   private final String requestName = "request";
   private final String responseName = "response";
@@ -34,13 +31,13 @@ public class MetricsCollectorTest {
 
   private final MetricsCollector metrics = new MetricsCollector();
 
-  @Before
-  public void setUp() {
+  @BeforeEach
+  void beforeEach() {
     metrics.resetMetric();
   }
 
   @Test
-  public void testOneRecord() {
+  void testOneRecord() {
     metrics.recordResult(protocol, requestName, responseName, ResponseType.SUCCESS, 100);
 
     assertThat(MetricsCollector.responsesCounter)
@@ -56,7 +53,7 @@ public class MetricsCollectorTest {
   }
 
   @Test
-  public void testMultipleRecords_sameStatus() {
+  void testMultipleRecords_sameStatus() {
     metrics.recordResult(protocol, requestName, responseName, ResponseType.FAILURE, 100);
     metrics.recordResult(protocol, requestName, responseName, ResponseType.FAILURE, 200);
 
@@ -77,7 +74,7 @@ public class MetricsCollectorTest {
   }
 
   @Test
-  public void testMultipleRecords_differentStatus() {
+  void testMultipleRecords_differentStatus() {
     metrics.recordResult(protocol, requestName, responseName, ResponseType.SUCCESS, 100);
     metrics.recordResult(protocol, requestName, responseName, ResponseType.FAILURE, 200);
 

prober/src/test/java/google/registry/monitoring/blackbox/testserver/TestServer.java

@@ -51,7 +51,7 @@ public class TestServer {
     this(new NioEventLoopGroup(1), localAddress, handlers);
   }
 
-  public TestServer(
+  private TestServer(
       EventLoopGroup eventLoopGroup,
       LocalAddress localAddress,
       ImmutableList<? extends ChannelHandler> handlers) {
@@ -108,7 +108,7 @@ public class TestServer {
      * @param destinationInput - Server will send back an {@link HttpResponseStatus} OK response
      *     when receiving a request with this host location
      */
-    public RedirectHandler(String redirectInput, String destinationInput, String destinationPath) {
+    RedirectHandler(String redirectInput, String destinationInput, String destinationPath) {
       this.redirectInput = redirectInput;
       this.destinationInput = destinationInput;
       this.destinationPath = destinationPath;

prober/src/test/java/google/registry/monitoring/blackbox/token/EppTokenTest.java

@@ -20,14 +20,11 @@ import google.registry.monitoring.blackbox.exception.UndeterminedStateException;
 import google.registry.monitoring.blackbox.message.EppRequestMessage;
 import google.registry.monitoring.blackbox.util.EppUtils;
 import io.netty.channel.Channel;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
+import org.junit.jupiter.api.Test;
 import org.mockito.Mockito;
 
 /** Unit Tests for each {@link Token} subtype (just {@link WebWhoisToken} for now) */
-@RunWith(JUnit4.class)
-public class EppTokenTest {
+class EppTokenTest {
 
   private static String TEST_HOST = "host";
   private static String TEST_TLD = "tld";
@@ -36,7 +33,7 @@ public class EppTokenTest {
   private EppToken transientEppToken = new EppToken.Transient(TEST_TLD, TEST_HOST);
 
   @Test
-  public void testMessageModificationSuccess_PersistentToken() throws UndeterminedStateException {
+  void testMessageModificationSuccess_PersistentToken() throws UndeterminedStateException {
 
     EppRequestMessage originalMessage = EppUtils.getCreateMessage(EppUtils.getSuccessResponse());
     String domainName = persistentEppToken.getCurrentDomainName();
@@ -51,7 +48,7 @@ public class EppTokenTest {
   }
 
   @Test
-  public void testMessageModificationSuccess_TransientToken() throws UndeterminedStateException {
+  void testMessageModificationSuccess_TransientToken() throws UndeterminedStateException {
 
     EppRequestMessage originalMessage = EppUtils.getCreateMessage(EppUtils.getSuccessResponse());
     String domainName = transientEppToken.getCurrentDomainName();
@@ -66,7 +63,7 @@ public class EppTokenTest {
   }
 
   @Test
-  public void testNext_persistentToken() {
+  void testNext_persistentToken() {
     String domainName = persistentEppToken.getCurrentDomainName();
     Channel mockChannel = Mockito.mock(Channel.class);
     persistentEppToken.setChannel(mockChannel);
@@ -78,7 +75,7 @@ public class EppTokenTest {
   }
 
   @Test
-  public void testNext_transientToken() {
+  void testNext_transientToken() {
     String domainName = transientEppToken.getCurrentDomainName();
     Channel mockChannel = Mockito.mock(Channel.class);
     transientEppToken.setChannel(mockChannel);

prober/src/test/java/google/registry/monitoring/blackbox/token/WebWhoisTokenTest.java

@@ -19,13 +19,10 @@ import static com.google.common.truth.Truth.assertThat;
 import com.google.common.collect.ImmutableList;
 import google.registry.monitoring.blackbox.exception.UndeterminedStateException;
 import google.registry.monitoring.blackbox.message.HttpRequestMessage;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
+import org.junit.jupiter.api.Test;
 
 /** Unit Tests for {@link WebWhoisToken} */
-@RunWith(JUnit4.class)
-public class WebWhoisTokenTest {
+class WebWhoisTokenTest {
 
   private static final String PREFIX = "whois.nic.";
   private static final String HOST = "starter";
@@ -35,10 +32,10 @@ public class WebWhoisTokenTest {
   private final ImmutableList<String> testDomains =
       ImmutableList.of(FIRST_TLD, SECOND_TLD, THIRD_TLD);
 
-  public Token webToken = new WebWhoisToken(testDomains);
+  private Token webToken = new WebWhoisToken(testDomains);
 
   @Test
-  public void testMessageModification() throws UndeterminedStateException {
+  void testMessageModification() throws UndeterminedStateException {
     // creates Request message with header
     HttpRequestMessage message = new HttpRequestMessage();
     message.headers().set("host", HOST);
@@ -49,13 +46,13 @@ public class WebWhoisTokenTest {
   }
 
   @Test
-  public void testHostOfToken() {
+  void testHostOfToken() {
     assertThat(webToken.host()).isEqualTo(PREFIX + FIRST_TLD);
     assertThat(webToken.host()).isEqualTo(PREFIX + FIRST_TLD);
   }
 
   @Test
-  public void testNextToken() {
+  void testNextToken() {
     assertThat(webToken.host()).isEqualTo(PREFIX + FIRST_TLD);
     webToken = webToken.next();