HTM-1258: Allow storing only one task per search index

build/qa/pmd-junit-ruleset.xml

@@ -9,7 +9,11 @@ SPDX-License-Identifier: MIT
 Junit ruleset. https://pmd.github.io/latest/pmd_userdocs_configuring_rules.html
 </description>
   <!-- if this fails check https://github.com/pmd/pmd/issues/2147 /-->
-  <rule ref="category/java/bestpractices.xml/JUnitTestsShouldIncludeAssert" />
+  <rule ref="category/java/bestpractices.xml/JUnitTestsShouldIncludeAssert">
+    <properties>
+      <property name="extraAssertMethodNames" value="assertThat" />
+    </properties>
+  </rule>
   <rule ref="category/java/bestpractices.xml/SimplifiableTestAssertion" />
   <rule ref="category/java/bestpractices.xml/JUnit5TestShouldBePackagePrivate" />
   <rule ref="category/java/errorprone.xml/UnnecessaryBooleanAssertion" />

src/main/java/org/tailormap/api/repository/events/SearchIndexEventHandler.java

@@ -7,11 +7,14 @@
 
 import java.lang.invoke.MethodHandles;
 import java.util.Map;
+import java.util.Objects;
+import java.util.Optional;
 import java.util.UUID;
 import org.quartz.JobDataMap;
 import org.quartz.JobKey;
 import org.quartz.Scheduler;
 import org.quartz.SchedulerException;
+import org.quartz.impl.matchers.GroupMatcher;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -85,6 +88,7 @@ public void beforeSaveSearchIndexEventHandler(SearchIndex searchIndex) throws Sc
     //   this case can already be handled requesting a delete of the scheduled task instead
     if (null != searchIndex.getSchedule()) {
       if (null == searchIndex.getSchedule().getUuid()) {
+        validateNoTaskExistsForIndex(searchIndex);
         // no task exists yet, create one
         logger.info("Creating new task associated with search index: {}", searchIndex.getName());
         TMJobDataMap jobDataMap =
@@ -122,4 +126,36 @@ public void beforeSaveSearchIndexEventHandler(SearchIndex searchIndex) throws Sc
       }
     }
   }
+
+  /**
+   * Validate that no scheduled task exists for the given index.
+   *
+   * @param searchIndex the search index to validate for scheduling a task
+   * @throws SchedulerException if there is a task that is already associated with the given index
+   */
+  private void validateNoTaskExistsForIndex(SearchIndex searchIndex) throws SchedulerException {
+    Optional<JobDataMap> jobDataMapOptional =
+        scheduler.getJobKeys(GroupMatcher.groupEquals(TaskType.INDEX.getValue())).stream()
+            .map(
+                jobKey -> {
+                  try {
+                    return scheduler.getJobDetail(jobKey).getJobDataMap();
+                  } catch (SchedulerException e) {
+                    logger.error("Error getting task detail", e);
+                    return null;
+                  }
+                })
+            .filter(Objects::nonNull)
+            .filter(
+                jobDataMap ->
+                    searchIndex.getId().equals(jobDataMap.getLongValue(IndexTask.INDEX_KEY)))
+            .findFirst();
+
+    if (jobDataMapOptional.isPresent()) {
+      logger.warn("A scheduled task already exists for search index: {}", searchIndex.getName());
+      throw new SchedulerException(
+          "A scheduled task already exists for search index: '%s'"
+              .formatted(searchIndex.getName()));
+    }
+  }
 }

src/test/java/org/tailormap/api/repository/events/SearchIndexEventHandlerTest.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2024 B3Partners B.V.
+ *
+ * SPDX-License-Identifier: MIT
+ */
+package org.tailormap.api.repository.events;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.containsString;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assumptions.assumingThat;
+
+import org.junit.jupiter.api.Test;
+import org.junitpioneer.jupiter.Issue;
+import org.quartz.SchedulerException;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.tailormap.api.annotation.PostgresIntegrationTest;
+import org.tailormap.api.persistence.SearchIndex;
+import org.tailormap.api.repository.SearchIndexRepository;
+
+@PostgresIntegrationTest
+class SearchIndexEventHandlerTest {
+  @Autowired SearchIndexEventHandler searchIndexEventHandler;
+  @Autowired SearchIndexRepository searchIndexRepository;
+
+  /**
+   * Test that a {@code SearchIndex} with a scheduled task that already exists cannot be saved with
+   * a new task through Spring Data REST.
+   */
+  @Test
+  @Issue("HTM-1258")
+  void testBeforeSaveSearchIndexEventHandler() {
+    SearchIndex existingSearchIndexWithSchedule = searchIndexRepository.findById(1L).orElse(null);
+
+    assumingThat(
+        null != existingSearchIndexWithSchedule
+            && null != existingSearchIndexWithSchedule.getSchedule()
+            && null != existingSearchIndexWithSchedule.getSchedule().getUuid(),
+        () -> {
+          final Exception actual =
+              assertThrows(
+                  SchedulerException.class,
+                  () -> {
+                    existingSearchIndexWithSchedule.getSchedule().setUuid(null);
+                    searchIndexEventHandler.beforeSaveSearchIndexEventHandler(
+                        existingSearchIndexWithSchedule);
+                  },
+                  "Test did not invoke expected exception");
+
+          assertThat(actual.getMessage(), containsString("scheduled task already exists"));
+        });
+  }
+}