Fix the build, reduce method visibility

pom.xml

@@ -670,7 +670,6 @@
                         <mutators>
                             <mutator>ALL</mutator>
                         </mutators>
-                        <testPlugin>testng</testPlugin>
                         <!-- Use multple threads to speed things up. Extend
                         timeouts to prevent false positives as a result of
                         contention. -->

rxjava-support/pom.xml

@@ -52,6 +52,11 @@
             <artifactId>junit-jupiter-api</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.mockito</groupId>
             <artifactId>mockito-core</artifactId>

rxjava-support/src/test/java/tech/picnic/rx/PicnicRxPluginsTest.java

@@ -21,7 +21,7 @@
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 
-public final class PicnicRxPluginsTest {
+final class PicnicRxPluginsTest {
   private final ConcurrentMap<Context, AtomicInteger> verificationCounters =
       new ConcurrentHashMap<>();
 
@@ -36,7 +36,7 @@ static void tearDown() {
   }
 
   @Test
-  public void testPropagate() {
+  void testPropagate() {
     Observable<Integer> obs = Observable.just(1, 2, 3);
 
     // Without context propagation
@@ -59,7 +59,7 @@ public void testPropagate() {
   }
 
   @Test
-  public void testObserveOnAnotherScheduler() {
+  void testObserveOnAnotherScheduler() {
     Observable<Integer> obs = Observable.just(1, 2, 3);
 
     Context ctx = Context.createRandom().applyToCurrentThread();
@@ -73,7 +73,7 @@ public void testObserveOnAnotherScheduler() {
   }
 
   @Test
-  public void testPropagateOnMultipleSchedulers() {
+  void testPropagateOnMultipleSchedulers() {
     Observable<Integer> obs = Observable.just(1, 2, 3);
 
     Context ctx = Context.createRandom().applyToCurrentThread();
@@ -87,7 +87,7 @@ public void testPropagateOnMultipleSchedulers() {
   }
 
   @Test
-  public void testNotLeaking() throws InterruptedException {
+  void testNotLeaking() throws InterruptedException {
     Observable<Integer> obs = Observable.just(1, 2, 3);
     Scheduler singleScheduler = Schedulers.single();
 
@@ -127,7 +127,7 @@ public void testNotLeaking() throws InterruptedException {
   }
 
   @Test
-  public void testContextSwitchBeforeConsumption() {
+  void testContextSwitchBeforeConsumption() {
     Observable<Integer> obs = Observable.just(1, 2, 3);
 
     // Context is propagated on scheduling, not on observable creation.
@@ -140,7 +140,7 @@ public void testContextSwitchBeforeConsumption() {
   }
 
   @Test
-  public void testPropagationOnSameThread() {
+  void testPropagationOnSameThread() {
     Observable<Integer> obs = Observable.just(1, 2, 3);
 
     Context ctx = Context.createRandom().applyToCurrentThread();
@@ -153,7 +153,7 @@ public void testPropagationOnSameThread() {
   }
 
   @Test
-  public void testEmptyContextIsPropagated() {
+  void testEmptyContextIsPropagated() {
     Observable<Integer> obs = Observable.just(1, 2, 3);
 
     ExecutorService es = Executors.newSingleThreadExecutor();
@@ -173,7 +173,7 @@ public void testEmptyContextIsPropagated() {
   }
 
   @Test
-  public void testTestSchedulerContextPropagation() throws InterruptedException {
+  void testTestSchedulerContextPropagation() throws InterruptedException {
     Context ctx = Context.createRandom().applyToCurrentThread();
 
     TestScheduler testScheduler = new TestScheduler();
@@ -190,7 +190,7 @@ public void testTestSchedulerContextPropagation() throws InterruptedException {
   }
 
   @Test
-  public void testDirectExecutor() {
+  void testDirectExecutor() {
     Context ctx = Context.createRandom().applyToCurrentThread();
 
     TestScheduler io = new TestScheduler();

rxjava-support/src/test/java/tech/picnic/rx/RetryStrategyTest.java

@@ -10,9 +10,9 @@
 import java.util.concurrent.atomic.AtomicInteger;
 import org.junit.jupiter.api.Test;
 
-public final class RetryStrategyTest {
+final class RetryStrategyTest {
   @Test
-  public void testOnlyIf() throws Exception {
+  void testOnlyIf() throws Exception {
     errorSource(2)
         .retryWhen(
             RetryStrategy.onlyIf(
@@ -31,7 +31,7 @@ public void testOnlyIf() throws Exception {
   }
 
   @Test
-  public void testExponentialBackoff() {
+  void testExponentialBackoff() {
     AtomicInteger retries = new AtomicInteger();
     TestScheduler scheduler = new TestScheduler();
     TestSubscriber<Integer> test =
@@ -57,7 +57,7 @@ public void testExponentialBackoff() {
   }
 
   @Test
-  public void testBoundedExponentialBackoff() {
+  void testBoundedExponentialBackoff() {
     AtomicInteger retries = new AtomicInteger();
     TestScheduler scheduler = new TestScheduler();
     TestSubscriber<Integer> test =
@@ -90,7 +90,7 @@ public void testBoundedExponentialBackoff() {
   }
 
   @Test
-  public void testFixedBackoff() {
+  void testFixedBackoff() {
     TestScheduler scheduler = new TestScheduler();
     TestSubscriber<Integer> test =
         errorSource(10)
@@ -107,7 +107,7 @@ public void testFixedBackoff() {
   }
 
   @Test
-  public void testCustomBackoff() {
+  void testCustomBackoff() {
     TestScheduler scheduler = new TestScheduler();
     TestSubscriber<Integer> test =
         errorSource(10)
@@ -124,7 +124,7 @@ public void testCustomBackoff() {
   }
 
   @Test
-  public void testTimes() throws Exception {
+  void testTimes() throws Exception {
     errorSource(10)
         .retryWhen(RetryStrategy.always().times(5).build())
         .test()

rxjava-support/src/test/java/tech/picnic/rx/RxSpring4UtilTest.java

@@ -51,7 +51,7 @@
 import org.springframework.web.servlet.mvc.method.annotation.SseEmitter;
 
 @TestInstance(Lifecycle.PER_CLASS)
-public final class RxSpring4UtilTest {
+final class RxSpring4UtilTest {
   private final TestScheduler testScheduler = new TestScheduler();
 
   @SuppressWarnings("NullAway")
@@ -69,20 +69,20 @@ void setUp() {
   }
 
   @Test
-  public void testSingleToDeferredResult() throws Exception {
+  void testSingleToDeferredResult() throws Exception {
     verifyAsyncGetRequest("/singleToDeferredResult?value=foo", OK, "foo");
     verifyAsyncGetRequest("/singleToDeferredResult?value=error", BAD_REQUEST, "");
   }
 
   @Test
-  public void testMaybeToDeferredResult() throws Exception {
+  void testMaybeToDeferredResult() throws Exception {
     verifyAsyncGetRequest("/maybeToDeferredResult", NOT_FOUND, "");
     verifyAsyncGetRequest("/maybeToDeferredResult?value=foo", OK, "foo");
     verifyAsyncGetRequest("/maybeToDeferredResult?value=error", BAD_REQUEST, "");
   }
 
   @Test
-  public void testObservableToDeferredResult() throws Exception {
+  void testObservableToDeferredResult() throws Exception {
     verifyAsyncGetRequest("/observableToDeferredResult?value=foo", OK, "[\"foo\"]");
     verifyAsyncGetRequest(
         "/observableToDeferredResult?value=bar&repeat=2", OK, "[\"bar\",\"bar\"]");
@@ -91,37 +91,37 @@ public void testObservableToDeferredResult() throws Exception {
   }
 
   @Test
-  public void testPublisherToDeferredResult() throws Exception {
+  void testPublisherToDeferredResult() throws Exception {
     verifyAsyncGetRequest("/publisherToDeferredResult?value=foo", OK, "[\"foo\"]");
     verifyAsyncGetRequest("/publisherToDeferredResult?value=bar&repeat=2", OK, "[\"bar\",\"bar\"]");
     verifyAsyncGetRequest("/publisherToDeferredResult?value=baz&repeat=0", OK, "[]");
     verifyAsyncGetRequest("/publisherToDeferredResult?value=error", BAD_REQUEST, "");
   }
 
   @Test
-  public void testCompletableToDeferredResult() throws Exception {
+  void testCompletableToDeferredResult() throws Exception {
     verifyAsyncGetRequest("/completableToDeferredResult?fail=false", OK, "");
     verifyAsyncGetRequest("/completableToDeferredResult?fail=true", BAD_REQUEST, "");
   }
 
   @Test
-  public void testObservableToSse() throws Exception {
+  void testObservableToSse() throws Exception {
     verifySyncGetRequest("/observableToSse?value=foo", OK, "data:foo\n\n");
     verifySyncGetRequest("/observableToSse?value=bar&repeat=2", OK, "data:bar\n\ndata:bar\n\n");
     verifySyncGetRequest("/observableToSse?value=baz&repeat=0", OK, "");
     verifyAsyncGetRequest("/observableToSse?value=error", BAD_REQUEST, "");
   }
 
   @Test
-  public void testPublisherToSse() throws Exception {
+  void testPublisherToSse() throws Exception {
     verifySyncGetRequest("/publisherToSse?value=foo", OK, "data:foo\n\n");
     verifySyncGetRequest("/publisherToSse?value=bar&repeat=2", OK, "data:bar\n\ndata:bar\n\n");
     verifySyncGetRequest("/publisherToSse?value=baz&repeat=0", OK, "");
     verifyAsyncGetRequest("/publisherToSse?value=error", BAD_REQUEST, "");
   }
 
   @Test
-  public void testPublisherToSseWithKeepAlive() throws Exception {
+  void testPublisherToSseWithKeepAlive() throws Exception {
     testScheduler.advanceTimeTo(0, MILLISECONDS);
     MockHttpServletResponse response =
         doGet("/publisherToSse/with-keep-alive?value=foo&repeat=2&interval=250")
@@ -157,7 +157,7 @@ public void testPublisherToSseWithKeepAlive() throws Exception {
   }
 
   @Test
-  public void testPublisherToSseWithKeepAliveAndError() throws Exception {
+  void testPublisherToSseWithKeepAliveAndError() throws Exception {
     testScheduler.advanceTimeTo(0, MILLISECONDS);
     MockHttpServletResponse response =
         doGet("/publisherToSse/with-keep-alive?value=error&repeat=1&interval=150")
@@ -172,7 +172,7 @@ public void testPublisherToSseWithKeepAliveAndError() throws Exception {
   }
 
   @Test
-  public void testPublisherToSseWithComplexObject() throws Exception {
+  void testPublisherToSseWithComplexObject() throws Exception {
     verifySyncGetRequest(
         "/publisherToSse/with-complex-object?repeat=2",
         OK,