Issue #2802541 by dagmar, mpdonadio: Timestamp field type doesn't provide sample values

core/lib/Drupal/Core/Field/Plugin/Field/FieldType/TimestampItem.php

@@ -2,8 +2,9 @@
 
 namespace Drupal\Core\Field\Plugin\Field\FieldType;
 
-use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\FieldItemBase;
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
 use Drupal\Core\TypedData\DataDefinition;
 
 /**
@@ -53,4 +54,14 @@ public static function schema(FieldStorageDefinitionInterface $field_definition)
     ];
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public static function generateSampleValue(FieldDefinitionInterface $field_definition) {
+    // Pick a random timestamp in the past year.
+    $timestamp = \Drupal::time()->getRequestTime() - mt_rand(0, 86400 * 365);
+    $values['value'] = $timestamp;
+    return $values;
+  }
+
 }

core/modules/field/tests/src/Kernel/Timestamp/TimestampItemTest.php

+<?php
+
+namespace Drupal\Tests\field\Kernel\Timestamp;
+
+use Drupal\Core\Field\FieldItemInterface;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\entity_test\Entity\EntityTest;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\Tests\field\Kernel\FieldKernelTestBase;
+
+/**
+ * Tests the timestamp fields.
+ *
+ * @group field
+ */
+class TimestampItemTest extends FieldKernelTestBase {
+
+  /**
+   * A field storage to use in this test class.
+   *
+   * @var \Drupal\field\Entity\FieldStorageConfig
+   */
+  protected $fieldStorage;
+
+  /**
+   * The field used in this test class.
+   *
+   * @var \Drupal\field\Entity\FieldConfig
+   */
+  protected $field;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    // Create a field with settings to validate.
+    $this->fieldStorage = FieldStorageConfig::create([
+      'field_name' => 'field_timestamp',
+      'type' => 'timestamp',
+      'entity_type' => 'entity_test',
+    ]);
+    $this->fieldStorage->save();
+    $this->field = FieldConfig::create([
+      'field_storage' => $this->fieldStorage,
+      'bundle' => 'entity_test',
+    ]);
+    $this->field->save();
+  }
+
+  /**
+   * Tests using entity fields of the datetime field type.
+   */
+  public function testDateTime() {
+    // Verify entity creation.
+    $entity = EntityTest::create();
+    $value = 1488914208;
+    $entity->field_timestamp = $value;
+    $entity->name->value = $this->randomMachineName();
+    $this->entityValidateAndSave($entity);
+
+    // Verify entity has been created properly.
+    $id = $entity->id();
+    $entity = EntityTest::load($id);
+    $this->assertTrue($entity->field_timestamp instanceof FieldItemListInterface, 'Field implements interface.');
+    $this->assertTrue($entity->field_timestamp[0] instanceof FieldItemInterface, 'Field item implements interface.');
+    $this->assertEquals($entity->field_timestamp->value, $value);
+    $this->assertEquals($entity->field_timestamp[0]->value, $value);
+
+    // Verify changing the date value.
+    $new_value = 1488914000;
+    $entity->field_timestamp->value = $new_value;
+    $this->assertEquals($entity->field_timestamp->value, $new_value);
+
+    // Read changed entity and assert changed values.
+    $this->entityValidateAndSave($entity);
+    $entity = EntityTest::load($id);
+    $this->assertEquals($entity->field_timestamp->value, $new_value);
+
+    // Test sample item generation.
+    $entity = EntityTest::create();
+    $entity->field_timestamp->generateSampleItems();
+    $this->entityValidateAndSave($entity);
+
+    // Ensure there is sample value a generated for the field.
+    $this->assertNotNull($entity->field_timestamp->value);
+  }
+
+}