Changed to nl.andrewl domain and added DailyScheduleTest

pom.xml

@@ -4,7 +4,7 @@
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
 
-    <groupId>nl.andrewlalis</groupId>
+    <groupId>nl.andrewl</groupId>
     <artifactId>simply-scheduled</artifactId>
     <version>1.0-SNAPSHOT</version>
     <packaging>jar</packaging>
@@ -42,15 +42,16 @@
         <java.version>11</java.version>
     </properties>
 
-    <build>
+    <distributionManagement>
-        <plugins>
+        <snapshotRepository>
-            <plugin>
+            <id>ossrh</id>
-                <groupId>org.apache.maven.plugins</groupId>
+            <url>https://s01.oss.sonatype.org/content/repositories/snapshots</url>
-                <artifactId>maven-surefire-plugin</artifactId>
+        </snapshotRepository>
-                <version>3.0.0-M5</version>
+        <repository>
-            </plugin>
+            <id>ossrh</id>
-        </plugins>
+            <url>https://s01.oss.sonatype.org/service/local/staging/deploy/maven2/</url>
-    </build>
+        </repository>
+    </distributionManagement>
 
     <dependencyManagement>
         <dependencies>
@@ -73,4 +74,54 @@
             <scope>test</scope>
         </dependency>
     </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>3.0.0-M5</version>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-gpg-plugin</artifactId>
+                <version>3.0.1</version>
+                <executions>
+                    <execution>
+                        <id>sign-artifacts</id>
+                        <phase>verify</phase>
+                        <goals>
+                            <goal>sign</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-javadoc-plugin</artifactId>
+                <version>3.3.0</version>
+                <executions>
+                    <execution>
+                        <id>attach-javadocs</id>
+                        <goals>
+                            <goal>jar</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-source-plugin</artifactId>
+                <version>3.2.1</version>
+                <executions>
+                    <execution>
+                        <id>attach-sources</id>
+                        <goals>
+                            <goal>jar-no-fork</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
 </project>

src/main/java/module-info.java

@@ -1,6 +1,10 @@
+/**
+ * The SimplyScheduled module.
+ */
 module simply_scheduled {
-	exports nl.andrewlalis.simply_scheduled;
+	exports nl.andrewl.simply_scheduled;
-	exports nl.andrewlalis.simply_scheduled.schedule;
+	exports nl.andrewl.simply_scheduled.schedule;
 
-	opens nl.andrewlalis.simply_scheduled;
+	// Needed for JUnit testing.
+	opens nl.andrewl.simply_scheduled;
 }

src/main/java/nl/andrewl/simply_scheduled/BasicScheduler.java

@@ -1,6 +1,6 @@
-package nl.andrewlalis.simply_scheduled;
+package nl.andrewl.simply_scheduled;
 
-import nl.andrewlalis.simply_scheduled.schedule.Task;
+import nl.andrewl.simply_scheduled.schedule.Task;
 
 import java.time.Clock;
 import java.time.Instant;
@@ -20,12 +20,22 @@ public class BasicScheduler extends Thread implements Scheduler {
 	private final ExecutorService executorService;
 	private boolean running = false;
 
+	/**
+	 * Constructs the scheduler using the given clock and executor service. This
+	 * constructor is most useful for test cases where a custom clock is used.
+	 * @param clock The clock to use.
+	 * @param executorService The executor service to use.
+	 */
 	public BasicScheduler(Clock clock, ExecutorService executorService) {
 		this.clock = clock;
 		this.tasks = new PriorityBlockingQueue<>();
 		this.executorService = executorService;
 	}
 
+	/**
+	 * Constructs the scheduler using the system's default clock, and a new
+	 * work-stealing thread pool.
+	 */
 	public BasicScheduler() {
 		this(Clock.systemDefaultZone(), Executors.newWorkStealingPool());
 	}

src/main/java/nl/andrewl/simply_scheduled/Demo.java

@@ -1,11 +1,14 @@
-package nl.andrewlalis.simply_scheduled;
+package nl.andrewl.simply_scheduled;
 
-import nl.andrewlalis.simply_scheduled.schedule.RepeatingSchedule;
+import nl.andrewl.simply_scheduled.schedule.RepeatingSchedule;
-import nl.andrewlalis.simply_scheduled.schedule.Schedule;
+import nl.andrewl.simply_scheduled.schedule.Schedule;
 
 import java.time.Instant;
 import java.time.temporal.ChronoUnit;
 
+/**
+ * Simple demonstration of scheduling functionality.
+ */
 public class Demo {
 	public static void main(String[] args) {
 		Scheduler scheduler = new BasicScheduler();

src/main/java/nl/andrewl/simply_scheduled/Scheduler.java

@@ -1,7 +1,7 @@
-package nl.andrewlalis.simply_scheduled;
+package nl.andrewl.simply_scheduled;
 
-import nl.andrewlalis.simply_scheduled.schedule.Schedule;
+import nl.andrewl.simply_scheduled.schedule.Task;
-import nl.andrewlalis.simply_scheduled.schedule.Task;
+import nl.andrewl.simply_scheduled.schedule.Schedule;
 
 /**
  * A scheduler is responsible for storing and executing tasks as defined by each

src/main/java/nl/andrewl/simply_scheduled/schedule/DailySchedule.java

@@ -1,4 +1,4 @@
-package nl.andrewlalis.simply_scheduled.schedule;
+package nl.andrewl.simply_scheduled.schedule;
 
 import java.time.*;
 import java.util.Optional;
@@ -11,10 +11,21 @@ public class DailySchedule implements Schedule {
 	private final ZoneId zoneId;
 	private final LocalTime time;
 
+	/**
+	 * Constructs a new schedule that will execute at the given time, using the
+	 * system's default time zone.
+	 * @param time The time at which to execute any tasks using this schedule.
+	 */
 	public DailySchedule(LocalTime time) {
 		this(time, ZoneId.systemDefault());
 	}
 
+	/**
+	 * Constructs a new schedule that will execute at the given time, using the
+	 * given zone id for time zone information.
+	 * @param time The time at which to execute any tasks using this schedule.
+	 * @param zoneId The time zone id.
+	 */
 	public DailySchedule(LocalTime time, ZoneId zoneId) {
 		this.time = time;
 		this.zoneId = zoneId;
@@ -23,9 +34,9 @@ public class DailySchedule implements Schedule {
 	@Override
 	public Optional<Instant> getNextExecutionTime(Instant referenceInstant) {
 		ZonedDateTime currentTime = referenceInstant.atZone(this.zoneId);
-		LocalDate currentDay = LocalDate.from(referenceInstant);
+		LocalDate currentDay = LocalDate.ofInstant(referenceInstant, this.zoneId);
 		ZonedDateTime sameDayExecution = currentDay.atTime(this.time).atZone(this.zoneId);
-		if (sameDayExecution.isBefore(currentTime)) {
+		if (sameDayExecution.isAfter(currentTime)) {
 			return Optional.of(sameDayExecution.toInstant());
 		}
 		return Optional.of(sameDayExecution.plusDays(1).toInstant());

src/main/java/nl/andrewl/simply_scheduled/schedule/HourlySchedule.java

@@ -1,4 +1,4 @@
-package nl.andrewlalis.simply_scheduled.schedule;
+package nl.andrewl.simply_scheduled.schedule;
 
 import java.time.Instant;
 import java.time.ZoneId;

src/main/java/nl/andrewl/simply_scheduled/schedule/RepeatingSchedule.java

@@ -1,4 +1,4 @@
-package nl.andrewlalis.simply_scheduled.schedule;
+package nl.andrewl.simply_scheduled.schedule;
 
 import java.time.Instant;
 import java.time.temporal.ChronoUnit;

src/main/java/nl/andrewl/simply_scheduled/schedule/Schedule.java

@@ -1,6 +1,6 @@
-package nl.andrewlalis.simply_scheduled.schedule;
+package nl.andrewl.simply_scheduled.schedule;
 
-import nl.andrewlalis.simply_scheduled.Scheduler;
+import nl.andrewl.simply_scheduled.Scheduler;
 
 import java.time.Instant;
 import java.util.Optional;

src/main/java/nl/andrewl/simply_scheduled/schedule/SpecificInstantSchedule.java

@@ -1,4 +1,4 @@
-package nl.andrewlalis.simply_scheduled.schedule;
+package nl.andrewl.simply_scheduled.schedule;
 
 import java.time.Instant;
 import java.time.ZonedDateTime;

src/main/java/nl/andrewl/simply_scheduled/schedule/Task.java

@@ -1,4 +1,4 @@
-package nl.andrewlalis.simply_scheduled.schedule;
+package nl.andrewl.simply_scheduled.schedule;
 
 import java.time.Clock;
 import java.time.Instant;
@@ -52,6 +52,15 @@ public class Task implements Comparable<Task>{
 		return schedule;
 	}
 
+	/**
+	 * Compares this task to another. This imposes a natural ordering of tasks
+	 * according to their schedule's next planned execution time, such that
+	 * tasks are ordered starting with those with the nearest execution time, to
+	 * those whose execution time is further in the future.
+	 * @param o The task to compare to.
+	 * @return -1 if this task's next execution time is before the other task's,
+	 * 1 if this task's next execution time is after the other, and 0 otherwise.
+	 */
 	@Override
 	public int compareTo(Task o) {
 		Instant now = clock.instant();

src/test/java/nl/andrewl/simply_scheduled/BasicSchedulerTest.java

@@ -1,8 +1,8 @@
-package nl.andrewlalis.simply_scheduled;
+package nl.andrewl.simply_scheduled;
 
-import nl.andrewlalis.simply_scheduled.schedule.RepeatingSchedule;
+import nl.andrewl.simply_scheduled.schedule.Task;
-import nl.andrewlalis.simply_scheduled.schedule.Schedule;
+import nl.andrewl.simply_scheduled.schedule.RepeatingSchedule;
-import nl.andrewlalis.simply_scheduled.schedule.Task;
+import nl.andrewl.simply_scheduled.schedule.Schedule;
 import org.junit.jupiter.api.Test;
 
 import java.time.Clock;

src/test/java/nl/andrewl/simply_scheduled/schedule/DailyScheduleTest.java

@@ -0,0 +1,40 @@
+package nl.andrewl.simply_scheduled.schedule;
+
+import java.time.*;
+import java.util.stream.Stream;
+
+/**
+ * Tests the ability of the {@link DailySchedule} to reliably give the correct
+ * next execution time.
+ */
+public class DailyScheduleTest extends ScheduleTest {
+	@Override
+	protected Stream<TestCase> getTestCases() {
+		var utc = ZoneOffset.UTC;
+		// For this test, we use a fixed clock at 12:30:45 on August 6, 2021, UTC.
+		Clock clock = Clock.fixed(ZonedDateTime.of(2021, 8, 6, 12, 30, 45, 0, utc).toInstant(), utc);
+		ZonedDateTime time = ZonedDateTime.ofInstant(clock.instant(), utc);
+		return Stream.of(
+				new TestCase( // A daily schedule whose time has already passed will be scheduled for tomorrow.
+						new DailySchedule(LocalTime.of(12, 0), utc),
+						clock.instant(),
+						time.plusDays(1).toLocalDate().atTime(12, 0).toInstant(utc)
+				),
+				new TestCase( // A daily schedule whose time has not yet passed will be scheduled for today.
+						new DailySchedule(LocalTime.of(18, 44, 3), utc),
+						clock.instant(),
+						time.toLocalDate().atTime(18, 44, 3).toInstant(utc)
+				),
+				new TestCase( // Account for a time zone which introduces some offset.
+						new DailySchedule(LocalTime.of(10, 30), ZoneOffset.ofHours(-5)),
+						clock.instant(),
+						time.toLocalDate().atTime(15, 30).toInstant(utc)
+				),
+				new TestCase( // Account for a time zone whose offset makes it such that the next event is scheduled for tomorrow, in UTC.
+						new DailySchedule(LocalTime.of(10, 30), ZoneOffset.ofHours(-1)),
+						clock.instant(),
+						time.plusDays(1).toLocalDate().atTime(11, 30).toInstant(utc)
+				)
+		);
+	}
+}

src/test/java/nl/andrewl/simply_scheduled/schedule/ScheduleTest.java

@@ -0,0 +1,43 @@
+package nl.andrewl.simply_scheduled.schedule;
+
+import org.junit.jupiter.api.Test;
+
+import java.time.Instant;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Abstract test class which can be extended to test the functionality of a
+ * particular schedule's {@link Schedule#getNextExecutionTime(Instant)} method.
+ */
+public abstract class ScheduleTest {
+	protected static class TestCase {
+		public final Schedule schedule;
+		public final Instant referenceInstant;
+		public final Instant expectedNextExecution;
+		public TestCase(Schedule schedule, Instant referenceInstant, Instant expectedNextExecution) {
+			this.schedule = schedule;
+			this.referenceInstant = referenceInstant;
+			this.expectedNextExecution = expectedNextExecution;
+		}
+	}
+
+	@Test
+	public void testGetNextExecutionTime() {
+		var cases = getTestCases().collect(Collectors.toList());
+		for (int i = 0; i < cases.size(); i++) {
+			var testCase = cases.get(i);
+			var r = testCase.schedule.getNextExecutionTime(testCase.referenceInstant);
+			if (testCase.expectedNextExecution == null) {
+				assertTrue(r.isEmpty(), "Case " + i + ": next execution time is not empty when it should be.");
+			} else {
+				assertTrue(r.isPresent(), "Case " + i + ": next execution time is not present when it should be.");
+				assertEquals(testCase.expectedNextExecution, r.get(), "Case " + i + ": expected next execution time does not match expected.");
+			}
+		}
+	}
+
+	protected abstract Stream<TestCase> getTestCases();
+}