OPENEUROPA-1905: Make sure that zero is a value.

src/Plugin/Field/FieldType/EntityVersionItem.php

@@ -18,7 +18,7 @@
  *   description = @Translation("Stores the version of the entity.")
  * )
  */
-class EntityVersionItem extends FieldItemBase {
+class EntityVersionItem extends FieldItemBase implements EntityVersionItemInterface {
 
   /**
    * {@inheritdoc}
@@ -48,7 +48,7 @@ public function isEmpty() {
     $minor = $this->get('minor')->getValue();
     $patch = $this->get('patch')->getValue();
 
-    return empty($major) || empty($minor) || empty($patch);
+    return $major === NULL || $major === '' || $minor === NULL || $minor === '' || $patch === NULL || $patch === '';
   }
 
   /**
@@ -66,29 +66,23 @@ public static function propertyDefinitions(FieldStorageDefinitionInterface $fiel
   }
 
   /**
-   * Increase the given version number category.
-   *
-   * @param string $category
+   * {@inheritdoc}
    */
   public function increase(string $category): void {
     $value = $this->get($category)->getValue();
     $this->set($category, ($value + 1));
   }
 
   /**
-   * Decrease the given version number category.
-   *
-   * @param string $category
+   * {@inheritdoc}
    */
   public function decrease(string $category): void {
     $value = $this->get($category)->getValue();
-    $this->set($category, ($value - 1));
+    $this->set($category, empty($value) ? 0 : ($value - 1));
   }
 
   /**
-   * Reset the given version number category to zero.
-   *
-   * @param string $category
+   * {@inheritdoc}
    */
   public function reset(string $category): void {
     $this->set($category, 0);

src/Plugin/Field/FieldType/EntityVersionItemInterface.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Drupal\entity_versions\Plugin\Field\FieldType;
+
+use Drupal\Core\Field\FieldItemInterface;
+
+/**
+ * Defines an interface for the entity_version field item.
+ */
+interface EntityVersionItemInterface extends FieldItemInterface {
+
+  /**
+   * Increase the given version number category.
+   *
+   * @param string $category
+   *   The version number category.
+   */
+  public function increase(string $category);
+
+  /**
+   * Decrease the given version number category.
+   *
+   * @param string $category
+   *   The version number category.
+   */
+  public function decrease(string $category);
+
+  /**
+   * Reset the given version number category to zero.
+   *
+   * @param string $category
+   *   The version number category.
+   */
+  public function reset(string $category);
+
+}

tests/Kernel/EntityVersionItemTest.php

@@ -19,6 +19,9 @@ class EntityVersionItemTest extends FieldKernelTestBase {
    */
   public static $modules = ['entity_versions'];
 
+  /**
+   * {@inheritdoc}
+   */
   protected function setUp() {
     parent::setUp();
 
@@ -66,8 +69,18 @@ public function testEntityVersionItem() {
     $this->assertEqual($entity->version->minor, 2);
     $this->assertEqual($entity->version->patch, 2);
 
-    // Use the field type method to decrease the values.
+    // Use the field type method to decrease the major number.
     $entity->version->first()->decrease('major');
+    $entity->save();
+
+    // Verify that the field value is changed.
+    $id = $entity->id();
+    $entity = EntityTest::load($id);
+    $this->assertEqual($entity->version->major, 1);
+    $this->assertEqual($entity->version->minor, 2);
+    $this->assertEqual($entity->version->patch, 2);
+
+    // Use the field type method to decrease values.
     $entity->version->first()->decrease('minor');
     $entity->version->first()->decrease('patch');
     $entity->save();
@@ -79,7 +92,7 @@ public function testEntityVersionItem() {
     $this->assertEqual($entity->version->minor, 1);
     $this->assertEqual($entity->version->patch, 1);
 
-    // Use the field type method to reset the values to zero.
+    // Use the field type method to reset values to zero.
     $entity->version->first()->reset('major');
     $entity->version->first()->reset('minor');
     $entity->version->first()->reset('patch');
@@ -91,6 +104,30 @@ public function testEntityVersionItem() {
     $this->assertEqual($entity->version->major, 0);
     $this->assertEqual($entity->version->minor, 0);
     $this->assertEqual($entity->version->patch, 0);
+
+    // Use the field type method to decrease values.
+    $entity->version->first()->decrease('major');
+    $entity->version->first()->decrease('minor');
+    $entity->version->first()->decrease('patch');
+    $entity->save();
+
+    // Verify that the field value has not changed.
+    $id = $entity->id();
+    $entity = EntityTest::load($id);
+    $this->assertEqual($entity->version->major, 0);
+    $this->assertEqual($entity->version->minor, 0);
+    $this->assertEqual($entity->version->patch, 0);
+
+    // Use the field type method to increase patch.
+    $entity->version->first()->increase('patch');
+    $entity->save();
+
+    // Verify that the field value is changed.
+    $id = $entity->id();
+    $entity = EntityTest::load($id);
+    $this->assertEqual($entity->version->major, 0);
+    $this->assertEqual($entity->version->minor, 0);
+    $this->assertEqual($entity->version->patch, 1);
   }
 
 }