Delay the start of the "ticks" after the first request.

implementation/src/main/java/io/smallrye/mutiny/helpers/test/AssertSubscriber.java

@@ -264,7 +264,7 @@ public AssertSubscriber<T> await() {
      * Awaits for the next item.
      * If no item have been received before the default timeout, an {@link AssertionError} is thrown.
      * <p>
-Note that it requests one item from the upstream.
+     * Note that it requests one item from the upstream.
      *
      * @return this {@link AssertSubscriber}
      * @see #awaitNextItems(int, int)

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

@@ -41,10 +41,8 @@ public IntervalMulti(
     @Override
     public void subscribe(MultiSubscriber<? super Long> actual) {
         IntervalRunnable runnable = new IntervalRunnable(actual, period, initialDelay, executor);
-
         actual.onSubscribe(runnable);
-        runnable.start();
-
+        // Only start the ticks when we get the first request.
     }
 
     static final class IntervalRunnable implements Runnable, Subscription {
@@ -54,6 +52,7 @@ static final class IntervalRunnable implements Runnable, Subscription {
         private final Duration initialDelay;
         private final ScheduledExecutorService executor;
         private volatile boolean cancelled;
+        private volatile boolean once = true;
 
         private final AtomicLong count = new AtomicLong();
         private ScheduledFuture<?> future;
@@ -105,6 +104,10 @@ public void request(long n) {
             if (n > 0) {
                 Subscriptions.add(requested, n);
             }
+            if (once) {
+                start();
+                once = false;
+            }
         }
 
         @Override

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

@@ -1,6 +1,7 @@
 package io.smallrye.mutiny.operators;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.awaitility.Awaitility.await;
 
 import java.time.Duration;
 import java.util.List;
@@ -48,6 +49,24 @@ public void testIntervalOfAFewMillis() {
         }
     }
 
+    @Test
+    public void testThatTicksStartAfterRequest() {
+        AssertSubscriber<Long> subscriber = AssertSubscriber.create();
+
+        Multi.createFrom().ticks()
+                .every(Duration.ofMillis(100))
+                .onItem().transform(l -> System.currentTimeMillis())
+                .subscribe().withSubscriber(subscriber);
+
+        await().pollDelay(Duration.ofMillis(500)).untilAsserted(subscriber::assertNotTerminated);
+
+        subscriber.request(100);
+        subscriber.awaitNextItems(10)
+                .cancel();
+
+        subscriber.assertNotTerminated();
+    }
+
     @Test
     public void testWithInfraExecutorAndNoDelay() throws InterruptedException {
         AssertSubscriber<Long> subscriber = AssertSubscriber.create(Long.MAX_VALUE);