--- /dev/null
+<?php
+
+namespace Drupal\dblog\Tests\Rest;
+
+use Drupal\Component\Serialization\Json;
+use Drupal\Core\Url;
+use Drupal\rest\Tests\RESTTestBase;
+
+/**
+ * Tests the watchdog database log resource.
+ *
+ * @group dblog
+ */
+class DbLogResourceTest extends RESTTestBase {
+
+ /**
+ * Modules to enable.
+ *
+ * @var array
+ */
+ public static $modules = ['hal', 'dblog'];
+
+ protected function setUp() {
+ parent::setUp();
+ // Enable REST API for the watchdog resource.
+ $this->enableService('dblog');
+ }
+
+ /**
+ * Writes a log messages and retrieves it via the REST API.
+ */
+ public function testWatchdog() {
+ // Write a log message to the DB.
+ $this->container->get('logger.channel.rest')->notice('Test message');
+ // Get the ID of the written message.
+ $id = db_query_range("SELECT wid FROM {watchdog} WHERE type = :type ORDER BY wid DESC", 0, 1, [':type' => 'rest'])
+ ->fetchField();
+
+ // Create a user account that has the required permissions to read
+ // the watchdog resource via the REST API.
+ $account = $this->drupalCreateUser(['restful get dblog']);
+ $this->drupalLogin($account);
+
+ $response = $this->httpRequest(Url::fromRoute('rest.dblog.GET.' . $this->defaultFormat, ['id' => $id, '_format' => $this->defaultFormat]), 'GET');
+ $this->assertResponse(200);
+ $this->assertHeader('content-type', $this->defaultMimeType);
+ $log = Json::decode($response);
+ $this->assertEqual($log['wid'], $id, 'Log ID is correct.');
+ $this->assertEqual($log['type'], 'rest', 'Type of log message is correct.');
+ $this->assertEqual($log['message'], 'Test message', 'Log message text is correct.');
+
+ // Request an unknown log entry.
+ $response = $this->httpRequest(Url::fromRoute('rest.dblog.GET.' . $this->defaultFormat, ['id' => 9999, '_format' => $this->defaultFormat]), 'GET');
+ $this->assertResponse(404);
+ $decoded = Json::decode($response);
+ $this->assertEqual($decoded['message'], 'Log entry with ID 9999 was not found', 'Response message is correct.');
+
+ // Make a bad request (a true malformed request would never be a route match).
+ $response = $this->httpRequest(Url::fromRoute('rest.dblog.GET.' . $this->defaultFormat, ['id' => 0, '_format' => $this->defaultFormat]), 'GET');
+ $this->assertResponse(400);
+ $decoded = Json::decode($response);
+ $this->assertEqual($decoded['message'], 'No log entry ID was provided', 'Response message is correct.');
+ }
+
+}