Misc code polishing edits

implementation/src/main/java/io/smallrye/mutiny/operators/multi/builders/NeverMulti.java

@@ -20,6 +20,7 @@ public final class NeverMulti extends AbstractMulti<Object> {
      * @param <T> the value type
      * @return the {@code multi}
      */
+    @SuppressWarnings("unchecked")
     public static <T> Multi<T> never() {
         return (Multi<T>) NEVER;
     }

implementation/src/main/java/io/smallrye/mutiny/operators/uni/builders/UniCreateFromPublisher.java

@@ -22,6 +22,7 @@ public UniCreateFromPublisher(Flow.Publisher<? extends T> publisher) {
     }
 
     @Override
+    @SuppressWarnings("unchecked")
     public void subscribe(UniSubscriber<? super T> subscriber) {
         new PublisherSubscriber(publisher, subscriber).forward();
     }

implementation/src/test/java/io/smallrye/mutiny/CompositeExceptionTest.java

@@ -22,8 +22,8 @@ public void testCreationWithArrays() {
         CompositeException ce2 = new CompositeException(IO, IAE, OUPS);
         assertThat(ce1).hasMessageContaining("iae").hasMessageContaining("io").hasMessageContaining("oups");
 
-        assertThat(ce1).getCause().isEqualTo(IAE);
-        assertThat(ce2).getCause().isEqualTo(IO);
+        assertThat(ce1).cause().isEqualTo(IAE);
+        assertThat(ce2).cause().isEqualTo(IO);
 
         assertThat(ce1.getCauses()).containsExactly(IAE, IO, OUPS);
         assertThat(ce1.getSuppressed()).containsExactly(IO, OUPS);
@@ -43,8 +43,8 @@ public void testCreationWithList() {
         CompositeException ce2 = new CompositeException(Arrays.asList(IO, IAE, OUPS));
         assertThat(ce1).hasMessageContaining("iae").hasMessageContaining("io").hasMessageContaining("oups");
 
-        assertThat(ce1).getCause().isEqualTo(IAE);
-        assertThat(ce2).getCause().isEqualTo(IO);
+        assertThat(ce1).cause().isEqualTo(IAE);
+        assertThat(ce2).cause().isEqualTo(IO);
 
         assertThat(ce1.getCauses()).containsExactly(IAE, IO, OUPS);
         assertThat(ce1.getSuppressed()).containsExactly(IO, OUPS);

implementation/src/test/java/io/smallrye/mutiny/groups/UniOnFailureRetryTest.java

@@ -209,7 +209,7 @@ public void testRetryWithBackOffReachingMaxAttempt() {
                     .onFailure().retry().withBackOff(Duration.ofMillis(10), Duration.ofSeconds(20)).withJitter(1.0)
                     .atMost(4)
                     .await().atMost(Duration.ofSeconds(5));
-        }).getCause() // Expected exception is wrapped in a java.util.concurrent.CompletionException
+        }).cause() // Expected exception is wrapped in a java.util.concurrent.CompletionException
                 .hasMessageContaining("boom")
                 .hasSuppressedException(new IllegalStateException("Retries exhausted: 4/4"));
     }

implementation/src/test/java/io/smallrye/mutiny/helpers/test/AssertSubscriberTest.java

@@ -82,22 +82,26 @@ public void testAssertItemsMessages() {
 
         subscriber.assertItems("a", "b", "c");
 
-        String m1 = "\nExpected to have received exactly:\n" +
-                "<a,b,c,d>\n" +
-                "but received:\n" +
-                "<a,b,c>.\n" +
-                "Mismatches are:\n" +
-                "\t- Missing expected item <d>";
+        String m1 = """
+
+                Expected to have received exactly:
+                <a,b,c,d>
+                but received:
+                <a,b,c>.
+                Mismatches are:
+                \t- Missing expected item <d>""";
         assertThatThrownBy(() -> subscriber.assertItems("a", "b", "c", "d"))
                 .isInstanceOf(AssertionError.class)
                 .hasMessage(m1);
 
-        String m2 = "\nExpected to have received exactly\n" +
-                "<a,b>\n" +
-                "but received\n" +
-                "<a,b,c>.\n" +
-                "The following items were not expected:\n" +
-                "<c>";
+        String m2 = """
+
+                Expected to have received exactly
+                <a,b>
+                but received
+                <a,b,c>.
+                The following items were not expected:
+                <c>""";
         assertThatThrownBy(() -> subscriber.assertItems("a", "b"))
                 .isInstanceOf(AssertionError.class)
                 .hasMessage(m2);

implementation/src/test/java/io/smallrye/mutiny/operators/MultiCollectTest.java

@@ -535,8 +535,7 @@ public String toString() {
         }
 
         public boolean equals(Object object) {
-            if (object instanceof TestObject) {
-                TestObject test = (TestObject) object;
+            if (object instanceof TestObject test) {
                 return test.key.equals(this.key) &&
                         test.value.equals(this.value);
             }

implementation/src/test/java/io/smallrye/mutiny/operators/MultiMergeTest.java

@@ -210,7 +210,7 @@ public void testWithFailureCollectionWithMerge() {
     public void failureMustTriggerCancellations() {
         AtomicBoolean firstCancelled = new AtomicBoolean();
         Multi<Integer> first = Multi.createBy().repeating().uni(
-                () -> Uni.createFrom().item(123).onItem().delayIt().by(Duration.ofSeconds(5))).atMost(10l)
+                () -> Uni.createFrom().item(123).onItem().delayIt().by(Duration.ofSeconds(5))).atMost(10L)
                 .onCancellation().invoke(() -> firstCancelled.set(true));
         Multi<Integer> second = Multi.createFrom().failure(new IOException("boom"));
         AssertSubscriber<Integer> sub = Multi.createBy().merging().streams(first, second)

implementation/src/test/java/io/smallrye/mutiny/operators/UniOnEventTest.java

@@ -542,7 +542,7 @@ public void testActionsOnTerminationWithFailure() {
 
         subscriber.assertFailed().assertFailedWith(CompositeException.class, "boom");
         CompositeException compositeException = (CompositeException) subscriber.getFailure();
-        assertThat(compositeException).getRootCause().isInstanceOf(IOException.class).hasMessageContaining("boom");
+        assertThat(compositeException).rootCause().isInstanceOf(IOException.class).hasMessageContaining("boom");
         assertThat(compositeException.getCauses().get(1)).isInstanceOf(IOException.class).hasMessageContaining("tada");
         assertThat(Item).doesNotHaveValue(1);
         assertThat(subscription.get()).isNotNull();
@@ -590,7 +590,7 @@ public void testActionsOnTerminationWithSupplierOnFailure() {
 
         subscriber.assertFailed().assertFailedWith(CompositeException.class, "boom");
         CompositeException compositeException = (CompositeException) subscriber.getFailure();
-        assertThat(compositeException).getRootCause().isInstanceOf(IOException.class).hasMessageContaining("boom");
+        assertThat(compositeException).rootCause().isInstanceOf(IOException.class).hasMessageContaining("boom");
         assertThat(compositeException.getCauses().get(1)).isInstanceOf(IOException.class).hasMessageContaining("tada");
         assertThat(Item).doesNotHaveValue(1);
         assertThat(subscription.get()).isNotNull();
@@ -615,7 +615,7 @@ public void testActionsOnTerminationWithMapperThrowingException() {
 
         subscriber.assertFailed().assertFailedWith(CompositeException.class, "boom");
         CompositeException compositeException = (CompositeException) subscriber.getFailure();
-        assertThat(compositeException).getRootCause().isInstanceOf(IOException.class).hasMessageContaining("boom");
+        assertThat(compositeException).rootCause().isInstanceOf(IOException.class).hasMessageContaining("boom");
         assertThat(compositeException.getCauses().get(1)).isInstanceOf(RuntimeException.class).hasMessageContaining("tada");
         assertThat(Item).doesNotHaveValue(1);
         assertThat(subscription.get()).isNotNull();

implementation/src/test/java/io/smallrye/mutiny/operators/uni/UniJoinTest.java

@@ -72,7 +72,7 @@ void oneIsNull() {
     }
 
     @Nested
-    @SuppressWarnings("ResultOfMethodCallIgnored")
+    @SuppressWarnings({ "ResultOfMethodCallIgnored", "unchecked" })
     class Emptyness {
         @Test
         void emptyArraysJoinFirst() {