test: Migrate gax unit tests to Junit 5 (#2724)

This PR migrate all unit tests in Gax to Junit 5.

Other than standard direct replacements, some tests need to be rewritten
due to the following scenarios:
- `@Rule` does not exist anymore and there is no direct replacement. We
mostly use it to initialize a Mockito stub, replaced with
`@ExtendWith(MockitoExtension.class)`.
- Some tests were relying on try-catch to assert exceptions, replaced
with `assertThrows`. e.g.
[OperationsClientTest](https://github.com/googleapis/sdk-platform-java/pull/2724/files#diff-4530df761eff0854357165d951e1667d3810a5448ec2aa4b853a6331516cbde0)
- Parameterized tests in
[AbstractRetryingExecutorTest](https://github.com/googleapis/sdk-platform-java/pull/2724/files#diff-9c5f5c1d2fcef6c4164fc0171d01e7020aa7ebb7aa49615cf3743dc89c9b3d1d)

There are a few environment variable tests can be re-written with Junit
5, so we don't need to configure a
[profile](https://github.com/googleapis/sdk-platform-java/blob/main/gax-java/gax/pom.xml#L115-L128)
for it anymore, but they are not in the scope of this PR.

fixes: #1611.

gax-java/dependencies.properties

@@ -79,9 +79,12 @@ maven.org_graalvm_sdk=org.graalvm.sdk:graal-sdk:22.3.5
 
 # Testing maven artifacts
 maven.junit_junit=junit:junit:4.13.2
-maven.org_mockito_mockito_core=org.mockito:mockito-core:2.28.2
+maven.org_mockito_mockito_core=org.mockito:mockito-core:4.11.0
+maven.org_mockito_mockito_junit_jupiter=org.mockito:mockito-junit-jupiter:4.11.0
 maven.org_hamcrest_hamcrest_core=org.hamcrest:hamcrest-core:1.3
 maven.com_google_truth_truth=com.google.truth:truth:1.4.2
 maven.com_googlecode_java_diff_utils_diffutils=com.googlecode.java-diff-utils:diffutils:1.3.0
 maven.net_bytebuddy_byte_buddy=net.bytebuddy:byte-buddy:1.14.15
 maven.org_objenesis_objenesis=org.objenesis:objenesis:2.6
+maven.org_junit_jupiter_junit_jupiter_api=org.junit.jupiter:junit-jupiter-api:5.10.2
+maven.org_junit_jupiter_junit_jupiter_params=org.junit.jupiter:junit-jupiter-params:5.10.2

gax-java/gax-grpc/BUILD.bazel

@@ -35,8 +35,9 @@ _COMPILE_DEPS = [
 ]
 
 _TEST_COMPILE_DEPS = [
-    "@junit_junit//jar",
+    "@org_junit_jupiter_junit_jupiter_api//jar",
     "@org_mockito_mockito_core//jar",
+    "@org_mockito_mockito_junit_jupiter//jar",
     "@com_google_truth_truth//jar",
     "@io_grpc_grpc_java//core:inprocess",
     "@com_google_api_grpc_grpc_google_common_protos//jar",

gax-java/gax-grpc/src/test/java/com/google/api/gax/grpc/CallOptionsUtilTest.java

@@ -29,19 +29,20 @@
  */
 package com.google.api.gax.grpc;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertSame;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertSame;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import com.google.common.collect.ImmutableMap;
 import io.grpc.CallOptions;
 import io.grpc.Metadata.Key;
 import java.util.Map;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
-public class CallOptionsUtilTest {
+class CallOptionsUtilTest {
   @Test
-  public void testPutAndGetDynamicHeaderOption() {
+  void testPutAndGetDynamicHeaderOption() {
     String encodedRequestParams = "param1=value&param2.param3=value23";
     CallOptions options =
         CallOptionsUtil.putRequestParamsDynamicHeaderOption(
@@ -54,16 +55,18 @@ public void testPutAndGetDynamicHeaderOption() {
   }
 
   @Test
-  public void testPutAndGetDynamicHeaderOptionEmpty() {
+  void testPutAndGetDynamicHeaderOptionEmpty() {
     CallOptions options =
         CallOptionsUtil.putRequestParamsDynamicHeaderOption(CallOptions.DEFAULT, "");
     assertSame(CallOptions.DEFAULT, options);
     Map<Key<String>, String> headers = CallOptionsUtil.getDynamicHeadersOption(options);
     assertTrue(headers.isEmpty());
   }
 
-  @Test(expected = NullPointerException.class)
-  public void testPutAndGetHeaderOptionNull() {
-    CallOptionsUtil.putRequestParamsDynamicHeaderOption(CallOptions.DEFAULT, null);
+  @Test
+  void testPutAndGetHeaderOptionNull() {
+    assertThrows(
+        NullPointerException.class,
+        () -> CallOptionsUtil.putRequestParamsDynamicHeaderOption(CallOptions.DEFAULT, null));
   }
 }

gax-java/gax-grpc/src/test/java/com/google/api/gax/grpc/ChannelPoolTest.java

@@ -69,29 +69,26 @@
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
-import org.junit.After;
-import org.junit.Assert;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
 import org.mockito.ArgumentCaptor;
 import org.mockito.Mockito;
 import org.mockito.stubbing.Answer;
 
-@RunWith(JUnit4.class)
-public class ChannelPoolTest {
+class ChannelPoolTest {
   private static final int DEFAULT_AWAIT_TERMINATION_SEC = 10;
   private ChannelPool pool;
 
-  @After
-  public void cleanup() throws InterruptedException {
+  @AfterEach
+  void cleanup() throws InterruptedException {
     Preconditions.checkNotNull(pool, "Channel pool was never created");
     pool.shutdown();
     pool.awaitTermination(DEFAULT_AWAIT_TERMINATION_SEC, TimeUnit.SECONDS);
   }
 
   @Test
-  public void testAuthority() throws IOException {
+  void testAuthority() throws IOException {
     ManagedChannel sub1 = Mockito.mock(ManagedChannel.class);
     ManagedChannel sub2 = Mockito.mock(ManagedChannel.class);
 
@@ -105,7 +102,7 @@ public void testAuthority() throws IOException {
   }
 
   @Test
-  public void testRoundRobin() throws IOException {
+  void testRoundRobin() throws IOException {
     ManagedChannel sub1 = Mockito.mock(ManagedChannel.class);
     ManagedChannel sub2 = Mockito.mock(ManagedChannel.class);
 
@@ -144,7 +141,7 @@ private void verifyTargetChannel(
   }
 
   @Test
-  public void ensureEvenDistribution() throws InterruptedException, IOException {
+  void ensureEvenDistribution() throws InterruptedException, IOException {
     int numChannels = 10;
     final ManagedChannel[] channels = new ManagedChannel[numChannels];
     final AtomicInteger[] counts = new AtomicInteger[numChannels];
@@ -197,7 +194,7 @@ public void ensureEvenDistribution() throws InterruptedException, IOException {
 
   // Test channelPrimer is called same number of times as poolSize if executorService is set to null
   @Test
-  public void channelPrimerShouldCallPoolConstruction() throws IOException {
+  void channelPrimerShouldCallPoolConstruction() throws IOException {
     ChannelPrimer mockChannelPrimer = Mockito.mock(ChannelPrimer.class);
     ManagedChannel channel1 = Mockito.mock(ManagedChannel.class);
     ManagedChannel channel2 = Mockito.mock(ManagedChannel.class);
@@ -215,7 +212,7 @@ public void channelPrimerShouldCallPoolConstruction() throws IOException {
 
   // Test channelPrimer is called periodically, if there's an executorService
   @Test
-  public void channelPrimerIsCalledPeriodically() throws IOException {
+  void channelPrimerIsCalledPeriodically() throws IOException {
     ChannelPrimer mockChannelPrimer = Mockito.mock(ChannelPrimer.class);
     ManagedChannel channel1 = Mockito.mock(ManagedChannel.class);
     ManagedChannel channel2 = Mockito.mock(ManagedChannel.class);
@@ -266,7 +263,7 @@ public void channelPrimerIsCalledPeriodically() throws IOException {
   // ----
   // call should be allowed to complete and the channel should not be shutdown
   @Test
-  public void callShouldCompleteAfterCreation() throws IOException {
+  void callShouldCompleteAfterCreation() throws IOException {
     ManagedChannel underlyingChannel = Mockito.mock(ManagedChannel.class);
     ManagedChannel replacementChannel = Mockito.mock(ManagedChannel.class);
     FakeChannelFactory channelFactory =
@@ -314,7 +311,7 @@ public void callShouldCompleteAfterCreation() throws IOException {
 
   // call should be allowed to complete and the channel should not be shutdown
   @Test
-  public void callShouldCompleteAfterStarted() throws IOException {
+  void callShouldCompleteAfterStarted() throws IOException {
     final ManagedChannel underlyingChannel = Mockito.mock(ManagedChannel.class);
     ManagedChannel replacementChannel = Mockito.mock(ManagedChannel.class);
 
@@ -359,7 +356,7 @@ public void callShouldCompleteAfterStarted() throws IOException {
 
   // Channel should be shutdown after a refresh all the calls have completed
   @Test
-  public void channelShouldShutdown() throws IOException {
+  void channelShouldShutdown() throws IOException {
     ManagedChannel underlyingChannel = Mockito.mock(ManagedChannel.class);
     ManagedChannel replacementChannel = Mockito.mock(ManagedChannel.class);
 
@@ -402,7 +399,7 @@ public void channelShouldShutdown() throws IOException {
   }
 
   @Test
-  public void channelRefreshShouldSwapChannels() throws IOException {
+  void channelRefreshShouldSwapChannels() throws IOException {
     ManagedChannel underlyingChannel1 = Mockito.mock(ManagedChannel.class);
     ManagedChannel underlyingChannel2 = Mockito.mock(ManagedChannel.class);
 
@@ -442,7 +439,7 @@ public void channelRefreshShouldSwapChannels() throws IOException {
   }
 
   @Test
-  public void channelCountShouldNotChangeWhenOutstandingRpcsAreWithinLimits() throws Exception {
+  void channelCountShouldNotChangeWhenOutstandingRpcsAreWithinLimits() throws Exception {
     ScheduledExecutorService executor = Mockito.mock(ScheduledExecutorService.class);
 
     List<ManagedChannel> channels = new ArrayList<>();
@@ -521,7 +518,7 @@ public void channelCountShouldNotChangeWhenOutstandingRpcsAreWithinLimits() thro
   }
 
   @Test
-  public void removedIdleChannelsAreShutdown() throws Exception {
+  void removedIdleChannelsAreShutdown() throws Exception {
     ScheduledExecutorService executor = Mockito.mock(ScheduledExecutorService.class);
 
     List<ManagedChannel> channels = new ArrayList<>();
@@ -561,7 +558,7 @@ public void removedIdleChannelsAreShutdown() throws Exception {
   }
 
   @Test
-  public void removedActiveChannelsAreShutdown() throws Exception {
+  void removedActiveChannelsAreShutdown() throws Exception {
     ScheduledExecutorService executor = Mockito.mock(ScheduledExecutorService.class);
 
     List<ManagedChannel> channels = new ArrayList<>();
@@ -622,7 +619,7 @@ public void removedActiveChannelsAreShutdown() throws Exception {
   }
 
   @Test
-  public void testReleasingClientCallCancelEarly() throws IOException {
+  void testReleasingClientCallCancelEarly() throws IOException {
     ClientCall mockClientCall = Mockito.mock(ClientCall.class);
     Mockito.doAnswer(invocation -> null).when(mockClientCall).cancel(Mockito.any(), Mockito.any());
     ManagedChannel fakeChannel = Mockito.mock(ManagedChannel.class);
@@ -650,7 +647,7 @@ public void testReleasingClientCallCancelEarly() throws IOException {
     Color request = Color.newBuilder().setRed(0.5f).build();
 
     IllegalStateException e =
-        Assert.assertThrows(
+        Assertions.assertThrows(
             IllegalStateException.class,
             () ->
                 streamingCallable.call(
@@ -675,7 +672,7 @@ public void onComplete() {}
   }
 
   @Test
-  public void testDoubleRelease() throws Exception {
+  void testDoubleRelease() throws Exception {
     FakeLogHandler logHandler = new FakeLogHandler();
     ChannelPool.LOG.addHandler(logHandler);
 

gax-java/gax-grpc/src/test/java/com/google/api/gax/grpc/GaxGrpcPropertiesTest.java

@@ -29,31 +29,28 @@
  */
 package com.google.api.gax.grpc;
 
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.regex.Pattern;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
+import org.junit.jupiter.api.Test;
 
-@RunWith(JUnit4.class)
-public class GaxGrpcPropertiesTest {
+class GaxGrpcPropertiesTest {
 
   @Test
-  public void testGrpcVersion() {
+  void testGrpcVersion() {
     String grpcVersion = GaxGrpcProperties.getGrpcVersion();
     assertTrue(Pattern.compile("^\\d+\\.\\d+\\.\\d+").matcher(grpcVersion).find());
   }
 
   @Test
-  public void testGaxGrpcVersion() {
+  void testGaxGrpcVersion() {
     String gaxGrpcVersion = GaxGrpcProperties.getGaxGrpcVersion();
     assertNotNull(gaxGrpcVersion);
   }
 
   @Test
-  public void testDefaultHeaderPattern() {
+  void testDefaultHeaderPattern() {
     assertTrue(
         GaxGrpcProperties.getDefaultApiClientHeaderPattern()
             .matcher("gl-java/1.8_00 gapic/1.2.3-alpha gax/1.5.0 grpc/1.7.0")

gax-java/gax-grpc/src/test/java/com/google/api/gax/grpc/GrpcApiExceptionFactoryTest.java

@@ -44,13 +44,10 @@
 import io.grpc.StatusException;
 import io.grpc.StatusRuntimeException;
 import java.util.Collections;
-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;
 
-@RunWith(JUnit4.class)
-public class GrpcApiExceptionFactoryTest {
+class GrpcApiExceptionFactoryTest {
 
   private static final ErrorInfo ERROR_INFO =
       ErrorInfo.newBuilder()
@@ -72,13 +69,13 @@ public class GrpcApiExceptionFactoryTest {
 
   private GrpcApiExceptionFactory factory;
 
-  @Before
-  public void setUp() throws Exception {
+  @BeforeEach
+  void setUp() throws Exception {
     factory = new GrpcApiExceptionFactory(Collections.emptySet());
   }
 
   @Test
-  public void create_shouldCreateApiExceptionWithErrorDetailsForStatusException() {
+  void create_shouldCreateApiExceptionWithErrorDetailsForStatusException() {
     Metadata trailers = new Metadata();
     Status status = Status.newBuilder().addAllDetails(RAW_ERROR_MESSAGES).build();
     trailers.put(
@@ -91,7 +88,7 @@ public void create_shouldCreateApiExceptionWithErrorDetailsForStatusException()
   }
 
   @Test
-  public void create_shouldCreateApiExceptionWithErrorDetailsForStatusRuntimeException() {
+  void create_shouldCreateApiExceptionWithErrorDetailsForStatusRuntimeException() {
     Metadata trailers = new Metadata();
     Status status = Status.newBuilder().addAllDetails(RAW_ERROR_MESSAGES).build();
     trailers.put(
@@ -104,7 +101,7 @@ public void create_shouldCreateApiExceptionWithErrorDetailsForStatusRuntimeExcep
   }
 
   @Test
-  public void create_shouldCreateApiExceptionWithNoErrorDetailsIfMetadataIsNull() {
+  void create_shouldCreateApiExceptionWithNoErrorDetailsIfMetadataIsNull() {
     StatusRuntimeException statusException = new StatusRuntimeException(GRPC_STATUS, null);
 
     ApiException actual = factory.create(statusException);
@@ -113,7 +110,7 @@ public void create_shouldCreateApiExceptionWithNoErrorDetailsIfMetadataIsNull()
   }
 
   @Test
-  public void create_shouldCreateApiExceptionWithNoErrorDetailsIfMetadataDoesNotHaveErrorDetails() {
+  void create_shouldCreateApiExceptionWithNoErrorDetailsIfMetadataDoesNotHaveErrorDetails() {
     StatusRuntimeException statusException =
         new StatusRuntimeException(GRPC_STATUS, new Metadata());
 
@@ -123,7 +120,7 @@ public void create_shouldCreateApiExceptionWithNoErrorDetailsIfMetadataDoesNotHa
   }
 
   @Test
-  public void create_shouldCreateApiExceptionWithNoErrorDetailsIfStatusIsMalformed() {
+  void create_shouldCreateApiExceptionWithNoErrorDetailsIfStatusIsMalformed() {
     Metadata trailers = new Metadata();
     Status status = Status.newBuilder().addDetails(Any.pack(ERROR_INFO)).build();
     byte[] bytes = status.toByteArray();