GH-1490 - Allow resetting the TimeMachine shift.

Author: odrotbohm

spring-modulith-moments/src/main/java/org/springframework/modulith/moments/support/Moments.java

@@ -123,6 +123,13 @@ Moments shiftBy(Duration duration) {
 		return this;
 	}
 
+	Moments reset() {
+
+		this.shift = Duration.ZERO;
+
+		return this;
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.modulith.moments.support.Now#now()

spring-modulith-moments/src/main/java/org/springframework/modulith/moments/support/TimeMachine.java

@@ -59,4 +59,13 @@ public LocalDateTime now() {
 	public Moments shiftBy(Duration duration) {
 		return super.shiftBy(duration);
 	}
+
+	/**
+	 * @see org.springframework.modulith.moments.support.Moments#reset()
+	 * @since 2.0.1
+	 */
+	@Override
+	public Moments reset() {
+		return super.reset();
+	}
 }

spring-modulith-moments/src/test/java/org/springframework/modulith/moments/support/MomentsUnitTests.java

@@ -29,6 +29,7 @@
 import java.time.temporal.WeekFields;
 import java.util.Locale;
 
+import org.assertj.core.data.TemporalUnitOffset;
 import org.junit.jupiter.api.Test;
 import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.modulith.moments.DayHasPassed;
@@ -47,6 +48,8 @@
  */
 class MomentsUnitTests {
 
+	static final TemporalUnitOffset ACCEPTABLE_OFFSET = within(50, ChronoUnit.MILLIS);
+
 	ApplicationEventPublisher events = mock(ApplicationEventPublisher.class);
 	Clock clock = Clock.systemUTC();
 
@@ -180,7 +183,20 @@ void returnsInstant() {
 		var instant = hourly.instant();
 		var now = hourly.now();
 
-		assertThat(LocalDateTime.ofInstant(instant, ZoneOffset.UTC)).isCloseTo(now, within(50, ChronoUnit.MILLIS));
+		assertThat(LocalDateTime.ofInstant(instant, ZoneOffset.UTC)).isCloseTo(now, ACCEPTABLE_OFFSET);
+	}
+
+	@Test // GH-1490
+	void resettingWipesShift() {
+
+		var now = hourly.instant();
+		var afterShift = hourly.shiftBy(Duration.ofMinutes(1)).instant();
+
+		assertThat(now.plus(Duration.ofMinutes(1))).isCloseTo(afterShift, ACCEPTABLE_OFFSET);
+
+		var afterReset = hourly.reset().instant();
+
+		assertThat(afterReset).isCloseTo(now, ACCEPTABLE_OFFSET);
 	}
 
 	private Duration getNumberOfDaysForThreeMonth(LocalDate date) {