Issue #3091478 by lauriii, Tim Bozeman, malcomio, tim.plunkett, adeshsharma,...

Issue #3091478 by lauriii, Tim Bozeman, malcomio, tim.plunkett, adeshsharma, longwave, EclipseGc, bnjmnm, alexpott, larowlan, amateescu, dpi: Improve StringItem::generateSampleValue()

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

@@ -72,7 +72,47 @@ public function getConstraints() {
    */
   public static function generateSampleValue(FieldDefinitionInterface $field_definition) {
     $random = new Random();
-    $values['value'] = $random->word(mt_rand(1, $field_definition->getSetting('max_length')));
+    $max_length = $field_definition->getSetting('max_length');
+
+    // When the maximum length is less than 15, or the field needs to be unique,
+    // generate a random word using the maximum length.
+    if ($max_length <= 15 || $field_definition->getConstraint('UniqueField')) {
+      $values['value'] = ucfirst($random->word($max_length));
+
+      return $values;
+    }
+
+    // The minimum length is either 10% of the maximum length, or 15 characters
+    // long, whichever is greater.
+    $min_length = max(ceil($max_length * 0.10), 15);
+
+    // Reduce the max length to allow us to add a period.
+    $max_length -= 1;
+
+    // The random value is generated multiple times to create a slight
+    // preference towards values that are closer to the minimum length of the
+    // string. For values larger than 255 (which is the default maximum value),
+    // the bias towards minimum length is increased. This is because the default
+    // maximum length of 255 is often used for fields that include shorter
+    // values (i.e. title).
+    $length = mt_rand($min_length, mt_rand($min_length, $max_length >= 255 ? mt_rand($min_length, $max_length) : $max_length));
+
+    $string = $random->sentences(1);
+    while (mb_strlen($string) < $length) {
+      $string .= " {$random->sentences(1)}";
+    }
+
+    if (mb_strlen($string) > $max_length) {
+      $string = substr($string, 0, $length);
+      $string = substr($string, 0, strrpos($string, ' '));
+    }
+
+    $string = rtrim($string, ' .');
+
+    // Ensure that the string ends with a full stop if there are multiple
+    // sentences.
+    $values['value'] = $string . (str_contains($string, '.') ? '.' : '');
+
     return $values;
   }
 

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

@@ -2,6 +2,7 @@
 
 namespace Drupal\Core\Field\Plugin\Field\FieldType;
 
+use Drupal\Component\Utility\Random;
 use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\FieldStorageDefinitionInterface;
 use Drupal\Core\TypedData\DataDefinition;
@@ -77,8 +78,18 @@ public function isEmpty() {
    * {@inheritdoc}
    */
   public static function generateSampleValue(FieldDefinitionInterface $field_definition) {
-    $values = parent::generateSampleValue($field_definition);
-    $suffix_length = $field_definition->getSetting('max_length') - 7;
+    $random = new Random();
+
+    $max_length = $field_definition->getSetting('max_length');
+    $min_length = min(10, $max_length);
+
+    // The random value is generated multiple times to create a slight
+    // preference towards values that are closer to the minimum length of the
+    // string.
+    $length = mt_rand($min_length, mt_rand($min_length, mt_rand($min_length, $max_length)));
+    $values['value'] = $random->word($length);
+
+    $suffix_length = $max_length - 7;
     foreach ($values as $key => $value) {
       $values[$key] = 'http://' . mb_substr($value, 0, $suffix_length);
     }

core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/UniqueFieldConstraint.php

@@ -17,7 +17,9 @@ class UniqueFieldConstraint extends Constraint {
   public $message = 'A @entity_type with @field_name %value already exists.';
 
   /**
-   * {@inheritdoc}
+   * Returns the name of the class that validates this constraint.
+   *
+   * @return string
    */
   public function validatedBy() {
     return '\Drupal\Core\Validation\Plugin\Validation\Constraint\UniqueFieldValueValidator';

core/modules/user/src/UserNameItem.php

@@ -2,6 +2,7 @@
 
 namespace Drupal\user;
 
+use Drupal\Component\Utility\Random;
 use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\Plugin\Field\FieldType\StringItem;
 
@@ -28,9 +29,36 @@ public function isEmpty() {
    * {@inheritdoc}
    */
   public static function generateSampleValue(FieldDefinitionInterface $field_definition) {
-    $values = parent::generateSampleValue($field_definition);
-    // User names larger than 60 characters won't pass validation.
-    $values['value'] = substr($values['value'], 0, UserInterface::USERNAME_MAX_LENGTH);
+    $random = new Random();
+    $max_length = min(UserInterface::USERNAME_MAX_LENGTH, $field_definition->getSetting('max_length'));
+
+    // Generate a list of words, which can be used to generate a string.
+    $words = explode(' ', $random->sentences(8));
+
+    // Begin with a username that is either 2 or 3 words.
+    $count = mt_rand(2, 3);
+
+    // Capitalize the words used in usernames 50% of the time.
+    $words = mt_rand(0, 1) ? array_map('ucfirst', $words) : $words;
+
+    // Username is a single long word 50% of the time. In the case of a single
+    // long word, sometimes the generated username may also contain periods in
+    // the middle of the username.
+    $separator = ' ';
+    if (mt_rand(0, 1)) {
+      $separator = '';
+      $count = mt_rand(2, 8);
+
+      // The username will start with a capital letter 50% of the time.
+      $words = mt_rand(0, 1) ? array_map('strtolower', $words) : $words;
+    }
+
+    $string = implode($separator, array_splice($words, 0, $count));
+
+    // Normalize the string to not be longer than the maximum length, and to not
+    // end with a space or a period.
+    $values['value'] = rtrim(mb_substr($string, 0, $max_length), ' .');
+
     return $values;
   }
 

core/modules/user/tests/src/Unit/UserNameItemTest.php

+<?php
+
+namespace Drupal\Tests\user\Unit;
+
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Tests\UnitTestCase;
+use Drupal\user\UserNameItem;
+
+/**
+ * Defines a test for the UserNameItem field-type.
+ *
+ * @group Field
+ * @coversDefaultClass \Drupal\user\UserNameItem
+ */
+class UserNameItemTest extends UnitTestCase {
+
+  /**
+   * Tests generating sample values.
+   *
+   * @param int $max_length
+   *   Maximum field length.
+   *
+   * @covers ::generateSampleValue
+   * @dataProvider providerMaxLength
+   */
+  public function testGenerateSampleValue(int $max_length): void {
+    $definition = $this->prophesize(FieldDefinitionInterface::class);
+    $definition->getSetting('max_length')->willReturn($max_length);
+
+    for ($i = 0; $i < 1000; $i++) {
+      $sample_value = UserNameItem::generateSampleValue($definition->reveal());
+      $this->assertLessThanOrEqual($max_length, mb_strlen($sample_value['value']));
+      $this->assertEquals(trim($sample_value['value'], ' '), $sample_value['value']);
+    }
+  }
+
+  /**
+   * Data provider for maximum-lengths.
+   *
+   * @return array
+   *   Test cases.
+   */
+  public function providerMaxLength(): array {
+    return [
+      '32' => [32],
+      '255' => [255],
+      '500' => [500],
+      '15' => [15],
+      '64' => [64],
+    ];
+  }
+
+}

core/tests/Drupal/Tests/Core/Field/StringItemTest.php

+<?php
+
+namespace Drupal\Tests\Core\Field;
+
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\Plugin\Field\FieldType\StringItem;
+use Drupal\Core\Validation\Plugin\Validation\Constraint\UniqueFieldConstraint;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * Defines a test for the StringItem field-type.
+ *
+ * @group Field
+ * @coversDefaultClass \Drupal\Core\Field\Plugin\Field\FieldType\StringItem
+ */
+class StringItemTest extends UnitTestCase {
+
+  /**
+   * Tests generating sample values.
+   *
+   * @param int $max_length
+   *   Maximum field length.
+   *
+   * @covers ::generateSampleValue
+   * @dataProvider providerMaxLength
+   */
+  public function testGenerateSampleValue(int $max_length): void {
+    foreach ([TRUE, FALSE] as $unique) {
+      $definition = $this->prophesize(FieldDefinitionInterface::class);
+      $constraints = $unique ? [$this->prophesize(UniqueFieldConstraint::class)] : [];
+      $definition->getConstraint('UniqueField')->willReturn($constraints);
+      $definition->getSetting('max_length')->willReturn($max_length);
+      for ($i = 0; $i < 1000; $i++) {
+        $sample_value = StringItem::generateSampleValue($definition->reveal());
+        // When the field value needs to be unique, the generated sample value
+        // should match the maximum length to ensure sufficient entropy.
+        if ($unique) {
+          $this->assertEquals($max_length, mb_strlen($sample_value['value']));
+        }
+        else {
+          $this->assertLessThanOrEqual($max_length, mb_strlen($sample_value['value']));
+        }
+      }
+    }
+  }
+
+  /**
+   * Data provider for maximum-lengths.
+   *
+   * @return array
+   *   Test cases.
+   */
+  public function providerMaxLength(): array {
+    return [
+      '32' => [32],
+      '255' => [255],
+      '500' => [500],
+      '15' => [15],
+      '4' => [4],
+      '64' => [64],
+    ];
+  }
+
+}

core/tests/Drupal/Tests/Core/Field/UriItemTest.php

+<?php
+
+namespace Drupal\Tests\Core\Field;
+
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\Plugin\Field\FieldType\UriItem;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * Defines a test for the UriItem field-type.
+ *
+ * @group Field
+ * @coversDefaultClass \Drupal\Core\Field\Plugin\Field\FieldType\UriItem
+ */
+class UriItemTest extends UnitTestCase {
+
+  /**
+   * Tests generating sample values.
+   *
+   * @param int $max_length
+   *   Maximum field length.
+   *
+   * @covers ::generateSampleValue
+   * @dataProvider providerMaxLength
+   */
+  public function testGenerateSampleValue(int $max_length): void {
+    $definition = $this->prophesize(FieldDefinitionInterface::class);
+    $definition->getSetting('max_length')->willReturn($max_length);
+
+    for ($i = 0; $i < 1000; $i++) {
+      $sample_value = UriItem::generateSampleValue($definition->reveal());
+      $this->assertLessThanOrEqual($max_length, mb_strlen($sample_value['value']));
+      $this->assertStringNotContainsString(' ', $sample_value['value']);
+    }
+  }
+
+  /**
+   * Data provider for maximum-lengths.
+   *
+   * @return array
+   *   Test cases.
+   */
+  public function providerMaxLength(): array {
+    return [
+      '32' => [32],
+      '255' => [255],
+      '500' => [500],
+      '15' => [15],
+      '64' => [64],
+    ];
+  }
+
+}