SONAR-16374 Add scheduled task to read PushEvents from DB

9 files changed, 488 insertions, 2 deletions

diff --git a/server/sonar-webserver-pushapi/src/main/java/org/sonar/server/pushapi/ServerPushWsModule.java b/server/sonar-webserver-pushapi/src/main/java/org/sonar/server/pushapi/ServerPushModule.java
index 091b56d7d56..f8f248abe6a 100644
--- a/server/sonar-webserver-pushapi/src/main/java/org/sonar/server/pushapi/ServerPushWsModule.java
+++ b/server/sonar-webserver-pushapi/src/main/java/org/sonar/server/pushapi/ServerPushModule.java
@@ -20,6 +20,8 @@
 package org.sonar.server.pushapi;
 
 import org.sonar.core.platform.Module;
+import org.sonar.server.pushapi.scheduler.polling.PushEventPollExecutorServiceImpl;
+import org.sonar.server.pushapi.scheduler.polling.PushEventPollScheduler;
 import org.sonar.server.pushapi.scheduler.purge.PushEventsPurgeExecutorServiceImpl;
 import org.sonar.server.pushapi.scheduler.purge.PushEventsPurgeInitializer;
 import org.sonar.server.pushapi.scheduler.purge.PushEventsPurgeSchedulerImpl;
@@ -27,7 +29,7 @@ import org.sonar.server.pushapi.sonarlint.SonarLintClientPermissionsValidator;
 import org.sonar.server.pushapi.sonarlint.SonarLintClientsRegistry;
 import org.sonar.server.pushapi.sonarlint.SonarLintPushAction;
 
-public class ServerPushWsModule extends Module {
+public class ServerPushModule extends Module {
 
   @Override
   protected void configureModule() {
@@ -37,6 +39,8 @@ public class ServerPushWsModule extends Module {
       SonarLintClientsRegistry.class,
       SonarLintPushAction.class,
 
+      PushEventPollExecutorServiceImpl.class,
+      PushEventPollScheduler.class,
       // Push Events Purge
       PushEventsPurgeSchedulerImpl.class,
       PushEventsPurgeExecutorServiceImpl.class,
diff --git a/server/sonar-webserver-pushapi/src/main/java/org/sonar/server/pushapi/scheduler/polling/PushEventExecutorService.java b/server/sonar-webserver-pushapi/src/main/java/org/sonar/server/pushapi/scheduler/polling/PushEventExecutorService.java
new file mode 100644
index 00000000000..56a7510e5c6
--- /dev/null
+++ b/server/sonar-webserver-pushapi/src/main/java/org/sonar/server/pushapi/scheduler/polling/PushEventExecutorService.java
@@ -0,0 +1,28 @@
+/*
+ * SonarQube
+ * Copyright (C) 2009-2022 SonarSource SA
+ * mailto:info AT sonarsource DOT com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+package org.sonar.server.pushapi.scheduler.polling;
+
+import java.util.concurrent.ScheduledExecutorService;
+import org.sonar.api.server.ServerSide;
+
+@ServerSide
+public interface PushEventExecutorService extends ScheduledExecutorService {
+
+}
diff --git a/server/sonar-webserver-pushapi/src/main/java/org/sonar/server/pushapi/scheduler/polling/PushEventPollExecutorServiceImpl.java b/server/sonar-webserver-pushapi/src/main/java/org/sonar/server/pushapi/scheduler/polling/PushEventPollExecutorServiceImpl.java
new file mode 100644
index 00000000000..fb356c5e1ca
--- /dev/null
+++ b/server/sonar-webserver-pushapi/src/main/java/org/sonar/server/pushapi/scheduler/polling/PushEventPollExecutorServiceImpl.java
@@ -0,0 +1,44 @@
+/*
+ * SonarQube
+ * Copyright (C) 2009-2022 SonarSource SA
+ * mailto:info AT sonarsource DOT com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+package org.sonar.server.pushapi.scheduler.polling;
+
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import org.sonar.api.server.ServerSide;
+import org.sonar.server.util.AbstractStoppableScheduledExecutorServiceImpl;
+
+import static java.lang.Thread.MIN_PRIORITY;
+import static java.util.concurrent.Executors.newSingleThreadScheduledExecutor;
+
+public class PushEventPollExecutorServiceImpl extends
+  AbstractStoppableScheduledExecutorServiceImpl<ScheduledExecutorService> implements PushEventExecutorService {
+
+  public PushEventPollExecutorServiceImpl() {
+    super(newSingleThreadScheduledExecutor(PushEventPollExecutorServiceImpl::createThread));
+  }
+
+  static Thread createThread(Runnable r) {
+    Thread thread = Executors.defaultThreadFactory().newThread(r);
+    thread.setName("PushEventPoll-%d");
+    thread.setPriority(MIN_PRIORITY);
+    thread.setDaemon(true);
+    return thread;
+  }
+}
diff --git a/server/sonar-webserver-pushapi/src/main/java/org/sonar/server/pushapi/scheduler/polling/PushEventPollScheduler.java b/server/sonar-webserver-pushapi/src/main/java/org/sonar/server/pushapi/scheduler/polling/PushEventPollScheduler.java
new file mode 100644
index 00000000000..883c943bceb
--- /dev/null
+++ b/server/sonar-webserver-pushapi/src/main/java/org/sonar/server/pushapi/scheduler/polling/PushEventPollScheduler.java
@@ -0,0 +1,150 @@
+/*
+ * SonarQube
+ * Copyright (C) 2009-2022 SonarSource SA
+ * mailto:info AT sonarsource DOT com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+package org.sonar.server.pushapi.scheduler.polling;
+
+import java.util.Collection;
+import java.util.Deque;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
+import org.jetbrains.annotations.NotNull;
+import org.sonar.api.Startable;
+import org.sonar.api.config.Configuration;
+import org.sonar.api.server.ServerSide;
+import org.sonar.api.utils.System2;
+import org.sonar.api.utils.log.Logger;
+import org.sonar.api.utils.log.Loggers;
+import org.sonar.db.DbClient;
+import org.sonar.db.DbSession;
+import org.sonar.db.project.ProjectDto;
+import org.sonar.db.pushevent.PushEventDto;
+import org.sonar.server.pushapi.sonarlint.SonarLintClient;
+import org.sonar.server.pushapi.sonarlint.SonarLintClientsRegistry;
+
+@ServerSide
+public class PushEventPollScheduler implements Startable {
+
+  private static final Logger LOG = Loggers.get(PushEventPollScheduler.class);
+
+  private static final String INITIAL_DELAY_IN_SECONDS = "sonar.pushevents.polling.initial.delay";
+  private static final String PERIOD_IN_SECONDS = "sonar.pushevents.polling.period";
+  private static final String PAGE_SIZE = "sonar.pushevents.polling.page.size";
+
+  private final PushEventExecutorService executorService;
+  private final SonarLintClientsRegistry clientsRegistry;
+  private final DbClient dbClient;
+  private final System2 system2;
+  private final Configuration config;
+  private Long lastPullTimestamp = null;
+  private String lastSeenUuid = null;
+
+  public PushEventPollScheduler(PushEventExecutorService executorService, SonarLintClientsRegistry clientsRegistry,
+    DbClient dbClient, System2 system2, Configuration config) {
+    this.executorService = executorService;
+    this.clientsRegistry = clientsRegistry;
+    this.dbClient = dbClient;
+    this.system2 = system2;
+    this.config = config;
+  }
+
+  @Override
+  public void start() {
+    this.executorService.scheduleAtFixedRate(this::tryBroadcastEvents, getInitialDelay(), getPeriod(), TimeUnit.SECONDS);
+  }
+
+  private void tryBroadcastEvents() {
+    try {
+      doBroadcastEvents();
+    } catch (Exception e) {
+      LOG.warn("Failed to poll for push events", e);
+    }
+  }
+
+  private void doBroadcastEvents() {
+    var clients = clientsRegistry.getClients();
+    if (clients.isEmpty()) {
+      lastPullTimestamp = null;
+      lastSeenUuid = null;
+      return;
+    }
+
+    if (lastPullTimestamp == null) {
+      lastPullTimestamp = system2.now();
+    }
+
+    var projectKeys = getClientsProjectKeys(clients);
+
+    try (DbSession dbSession = dbClient.openSession(false)) {
+      var projectUuids = getProjectUuids(projectKeys, dbSession);
+      Deque<PushEventDto> events = getPushEvents(dbSession, projectUuids);
+
+      LOG.debug("Received {} push events, attempting to broadcast to {} registered clients.", events.size(),
+        clients.size());
+
+      events.forEach(clientsRegistry::broadcastMessage);
+
+      if (!events.isEmpty()) {
+        var last = events.getLast();
+        lastPullTimestamp = last.getCreatedAt();
+        lastSeenUuid = last.getUuid();
+      }
+    }
+  }
+
+  private static Set<String> getClientsProjectKeys(List<SonarLintClient> clients) {
+    return clients.stream()
+      .map(SonarLintClient::getClientProjectKeys)
+      .flatMap(Collection::stream)
+      .collect(Collectors.toSet());
+  }
+
+  private Deque<PushEventDto> getPushEvents(DbSession dbSession, Set<String> projectUuids) {
+    return dbClient.pushEventDao().selectChunkByProjectUuids(dbSession, projectUuids, lastPullTimestamp, lastSeenUuid, getPageSize());
+  }
+
+  @NotNull
+  private Set<String> getProjectUuids(Set<String> projectKeys, DbSession dbSession) {
+    return dbClient.projectDao().selectProjectsByKeys(dbSession, projectKeys)
+      .stream().map(ProjectDto::getUuid)
+      .collect(Collectors.toSet());
+  }
+
+  public long getInitialDelay() {
+    // two minutes default initial delay
+    return config.getLong(INITIAL_DELAY_IN_SECONDS).orElse(2 * 60L);
+  }
+
+  public long getPeriod() {
+    // execute every 40 seconds
+    return config.getLong(PERIOD_IN_SECONDS).orElse(40L);
+  }
+
+  public long getPageSize() {
+    // 20 events per 40 seconds
+    return config.getLong(PAGE_SIZE).orElse(20L);
+  }
+
+  @Override
+  public void stop() {
+    // nothing to do
+  }
+
+}
diff --git a/server/sonar-webserver-pushapi/src/main/java/org/sonar/server/pushapi/sonarlint/SonarLintClientsRegistry.java b/server/sonar-webserver-pushapi/src/main/java/org/sonar/server/pushapi/sonarlint/SonarLintClientsRegistry.java
index d2508ada331..1d815f2371c 100644
--- a/server/sonar-webserver-pushapi/src/main/java/org/sonar/server/pushapi/sonarlint/SonarLintClientsRegistry.java
+++ b/server/sonar-webserver-pushapi/src/main/java/org/sonar/server/pushapi/sonarlint/SonarLintClientsRegistry.java
@@ -34,6 +34,7 @@ import org.sonar.core.util.issue.IssueChangeListener;
 import org.sonar.core.util.issue.IssueChangedEvent;
 import org.sonar.core.util.rule.RuleActivationListener;
 import org.sonar.core.util.rule.RuleSetChangedEvent;
+import org.sonar.db.pushevent.PushEventDto;
 import org.sonar.server.exceptions.ForbiddenException;
 import org.sonar.server.pushapi.issues.IssueChangeBroadcastUtils;
 import org.sonar.server.pushapi.issues.IssueChangeEventsDistributor;
@@ -86,6 +87,10 @@ public class SonarLintClientsRegistry implements RuleActivationListener, IssueCh
     LOG.debug("Removing SonarLint client");
   }
 
+  public List<SonarLintClient> getClients() {
+    return clients;
+  }
+
   public long countConnectedClients() {
     return clients.size();
   }
@@ -100,6 +105,11 @@ public class SonarLintClientsRegistry implements RuleActivationListener, IssueCh
     broadcastMessage(issueChangedEvent, IssueChangeBroadcastUtils.getFilterForEvent(issueChangedEvent));
   }
 
+  public void broadcastMessage(PushEventDto event) {
+    // TODO:: different task for broadcasting event
+    LOG.info("received event: ({}, {}) ", event.getUuid(), event.getName());
+  }
+
   public void broadcastMessage(RuleSetChangedEvent event, Predicate<SonarLintClient> filter) {
     clients.stream().filter(filter).forEach(c -> {
       Set<String> projectKeysInterestingForClient = new HashSet<>(c.getClientProjectKeys());
diff --git a/server/sonar-webserver-pushapi/src/test/java/org/sonar/server/pushapi/ServerPushWsModuleTest.java b/server/sonar-webserver-pushapi/src/test/java/org/sonar/server/pushapi/ServerPushWsModuleTest.java
index 9ef3dec04f2..87a78661495 100644
--- a/server/sonar-webserver-pushapi/src/test/java/org/sonar/server/pushapi/ServerPushWsModuleTest.java
+++ b/server/sonar-webserver-pushapi/src/test/java/org/sonar/server/pushapi/ServerPushWsModuleTest.java
@@ -28,7 +28,7 @@ public class ServerPushWsModuleTest {
   @Test
   public void verify_count_of_added_components() {
     ListContainer container = new ListContainer();
-    new ServerPushWsModule().configure(container);
+    new ServerPushModule().configure(container);
     assertThat(container.getAddedObjects()).isNotEmpty();
   }
 }
diff --git a/server/sonar-webserver-pushapi/src/test/java/org/sonar/server/pushapi/scheduler/polling/PushEventPollExecutorServiceImplTest.java b/server/sonar-webserver-pushapi/src/test/java/org/sonar/server/pushapi/scheduler/polling/PushEventPollExecutorServiceImplTest.java
new file mode 100644
index 00000000000..8bedaa7685f
--- /dev/null
+++ b/server/sonar-webserver-pushapi/src/test/java/org/sonar/server/pushapi/scheduler/polling/PushEventPollExecutorServiceImplTest.java
@@ -0,0 +1,39 @@
+/*
+ * SonarQube
+ * Copyright (C) 2009-2022 SonarSource SA
+ * mailto:info AT sonarsource DOT com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+package org.sonar.server.pushapi.scheduler.polling;
+
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class PushEventPollExecutorServiceImplTest {
+
+  @Test
+  public void create_executor() {
+    PushEventPollExecutorServiceImpl underTest = new PushEventPollExecutorServiceImpl();
+
+    assertThat(underTest.createThread(() -> {
+    }))
+      .extracting(Thread::getPriority, Thread::isDaemon, Thread::getName)
+      .containsExactly(Thread.MIN_PRIORITY, true, "PushEventPoll-%d");
+
+  }
+
+}
diff --git a/server/sonar-webserver-pushapi/src/test/java/org/sonar/server/pushapi/scheduler/polling/PushEventPollSchedulerTest.java b/server/sonar-webserver-pushapi/src/test/java/org/sonar/server/pushapi/scheduler/polling/PushEventPollSchedulerTest.java
new file mode 100644
index 00000000000..4d436f52971
--- /dev/null
+++ b/server/sonar-webserver-pushapi/src/test/java/org/sonar/server/pushapi/scheduler/polling/PushEventPollSchedulerTest.java
@@ -0,0 +1,209 @@
+/*
+ * SonarQube
+ * Copyright (C) 2009-2022 SonarSource SA
+ * mailto:info AT sonarsource DOT com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+package org.sonar.server.pushapi.scheduler.polling;
+
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+import org.junit.Rule;
+import org.junit.Test;
+import org.sonar.api.config.Configuration;
+import org.sonar.api.impl.utils.TestSystem2;
+import org.sonar.core.util.UuidFactoryFast;
+import org.sonar.db.DbTester;
+import org.sonar.db.pushevent.PushEventDto;
+import org.sonar.server.pushapi.sonarlint.SonarLintClient;
+import org.sonar.server.pushapi.sonarlint.SonarLintClientsRegistry;
+import org.sonar.server.util.AbstractStoppableExecutorService;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static java.util.Collections.emptyList;
+import static org.assertj.core.api.Assertions.assertThatCode;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+public class PushEventPollSchedulerTest {
+
+  private final SonarLintClientsRegistry clientsRegistry = mock(SonarLintClientsRegistry.class);
+
+  private static final long NOW = 1L;
+  private final TestSystem2 system2 = new TestSystem2().setNow(NOW);
+  private final Configuration config = mock(Configuration.class);
+
+  @Rule
+  public DbTester db = DbTester.create(system2);
+
+  private final SyncPushEventExecutorService executorService = new SyncPushEventExecutorService();
+
+  @Test
+  public void scheduler_should_be_resilient_to_failures() {
+    when(clientsRegistry.getClients()).thenThrow(new RuntimeException("I have a bad feelings about this"));
+
+    var underTest = new PushEventPollScheduler(executorService, clientsRegistry, db.getDbClient(), system2, config);
+    underTest.start();
+
+    assertThatCode(executorService::runCommand)
+      .doesNotThrowAnyException();
+
+    verify(clientsRegistry, times(0)).broadcastMessage(any(PushEventDto.class));
+  }
+
+  @Test
+  public void nothing_to_broadcast_when_client_list_is_empty() {
+    when(clientsRegistry.getClients()).thenReturn(emptyList());
+
+    var underTest = new PushEventPollScheduler(executorService, clientsRegistry, db.getDbClient(), system2, config);
+    underTest.start();
+
+    executorService.runCommand();
+
+    verify(clientsRegistry, times(0)).broadcastMessage(any(PushEventDto.class));
+  }
+
+  @Test
+  public void nothing_to_broadcast_when_no_push_events() {
+    var project = db.components().insertPrivateProject();
+
+    var sonarLintClient = mock(SonarLintClient.class);
+    when(sonarLintClient.getClientProjectKeys()).thenReturn(Set.of(project.getDbKey()));
+    when(clientsRegistry.getClients()).thenReturn(List.of(sonarLintClient));
+
+    var underTest = new PushEventPollScheduler(executorService, clientsRegistry, db.getDbClient(), system2, config);
+    underTest.start();
+
+    executorService.runCommand();
+
+    verify(clientsRegistry, times(0)).broadcastMessage(any(PushEventDto.class));
+  }
+
+  @Test
+  public void broadcast_push_events() {
+    var project = db.components().insertPrivateProject();
+
+    system2.setNow(1L);
+    var sonarLintClient = mock(SonarLintClient.class);
+    when(sonarLintClient.getClientProjectKeys()).thenReturn(Set.of(project.getDbKey()));
+    when(clientsRegistry.getClients()).thenReturn(List.of(sonarLintClient));
+
+    var underTest = new PushEventPollScheduler(executorService, clientsRegistry, db.getDbClient(), system2, config);
+    underTest.start();
+    executorService.runCommand();
+
+    verify(clientsRegistry, times(0)).broadcastMessage(any(PushEventDto.class));
+
+    system2.tick(); // tick=2
+    generatePushEvent(project.uuid());
+    generatePushEvent(project.uuid());
+
+    system2.tick(); // tick=3
+    generatePushEvent(project.uuid());
+
+    underTest.start();
+    executorService.runCommand();
+
+    verify(clientsRegistry, times(3)).broadcastMessage(any(PushEventDto.class));
+
+    system2.tick(); // tick=4
+    generatePushEvent(project.uuid());
+    generatePushEvent(project.uuid());
+
+    underTest.start();
+    executorService.runCommand();
+    verify(clientsRegistry, times(5)).broadcastMessage(any(PushEventDto.class));
+  }
+
+  @Test
+  public void broadcast_should_stop_polling_for_events_when_all_clients_unregister() {
+    var project = db.components().insertPrivateProject();
+
+    system2.setNow(1L);
+    var sonarLintClient = mock(SonarLintClient.class);
+    when(sonarLintClient.getClientProjectKeys()).thenReturn(Set.of(project.getDbKey()));
+    when(clientsRegistry.getClients()).thenReturn(List.of(sonarLintClient), emptyList());
+
+    var underTest = new PushEventPollScheduler(executorService, clientsRegistry, db.getDbClient(), system2, config);
+    underTest.start();
+    executorService.runCommand();
+
+    verify(clientsRegistry, times(0)).broadcastMessage(any(PushEventDto.class));
+
+    system2.tick(); // tick=2
+    generatePushEvent(project.uuid());
+
+    underTest.start();
+    executorService.runCommand();
+
+    // all clients have been unregistered, nothing to broadcast
+    verify(clientsRegistry, times(0)).broadcastMessage(any(PushEventDto.class));
+  }
+
+  private PushEventDto generatePushEvent(String projectUuid) {
+    var event = db.getDbClient().pushEventDao().insert(db.getSession(), new PushEventDto()
+      .setName("Event")
+      .setUuid(UuidFactoryFast.getInstance().create())
+      .setProjectUuid(projectUuid)
+      .setPayload("some-event".getBytes(UTF_8)));
+    db.commit();
+    return event;
+  }
+
+  private static class SyncPushEventExecutorService extends AbstractStoppableExecutorService<ScheduledExecutorService>
+    implements PushEventExecutorService {
+
+    private Runnable command;
+
+    public SyncPushEventExecutorService() {
+      super(null);
+    }
+
+    public void runCommand() {
+      command.run();
+    }
+
+    @Override
+    public ScheduledFuture<?> scheduleAtFixedRate(Runnable command, long initialDelay, long period, TimeUnit unit) {
+      this.command = command;
+      return null;
+    }
+
+    @Override
+    public ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit) {
+      return null;
+    }
+
+    @Override
+    public <V> ScheduledFuture<V> schedule(Callable<V> callable, long delay, TimeUnit unit) {
+      return null;
+    }
+
+    @Override
+    public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command, long initialDelay, long delay, TimeUnit unit) {
+      return null;
+    }
+
+  }
+
+}
diff --git a/server/sonar-webserver-pushapi/src/test/java/org/sonar/server/pushapi/sonarlint/SonarLintClientsRegistryTest.java b/server/sonar-webserver-pushapi/src/test/java/org/sonar/server/pushapi/sonarlint/SonarLintClientsRegistryTest.java
index 48cbb218411..084117b8ec1 100644
--- a/server/sonar-webserver-pushapi/src/test/java/org/sonar/server/pushapi/sonarlint/SonarLintClientsRegistryTest.java
+++ b/server/sonar-webserver-pushapi/src/test/java/org/sonar/server/pushapi/sonarlint/SonarLintClientsRegistryTest.java
@@ -78,10 +78,12 @@ public class SonarLintClientsRegistryTest {
     underTest.registerClient(sonarLintClient);
 
     assertThat(underTest.countConnectedClients()).isEqualTo(1);
+    assertThat(underTest.getClients()).contains(sonarLintClient);
 
     underTest.unregisterClient(sonarLintClient);
 
     assertThat(underTest.countConnectedClients()).isZero();
+    assertThat(underTest.getClients()).isEmpty();
     verify(sonarLintClient).close();
   }