first commit

core/modules/link/tests/modules/link_test_views/link_test_views.info.yml

@@ -0,0 +1,16 @@
+name: 'Link test views'
+type: module
+description: 'Provides default views for views link tests.'
+package: Testing
+# version: VERSION
+# core: 8.x
+dependencies:
+  - node
+  - views
+  - link
+
+# Information added by Drupal.org packaging script on 2017-04-19
+version: '8.3.1'
+core: '8.x'
+project: 'drupal'
+datestamp: 1492622988

core/modules/link/tests/modules/link_test_views/test_views/views.view.test_link_tokens.yml

@@ -0,0 +1,206 @@
+langcode: en
+status: true
+dependencies:
+  config:
+    - field.storage.node.field_link
+  module:
+    - link
+    - node
+    - user
+id: test_link_tokens
+label: link
+module: views
+description: ''
+tag: ''
+base_table: node_field_data
+base_field: nid
+core: 8.x
+display:
+  default:
+    display_plugin: default
+    id: default
+    display_title: Master
+    position: 0
+    display_options:
+      access:
+        type: perm
+        options:
+          perm: 'access content'
+      cache:
+        type: tag
+        options: {  }
+      query:
+        type: views_query
+        options:
+          disable_sql_rewrite: false
+          distinct: false
+          replica: false
+          query_comment: ''
+          query_tags: {  }
+      exposed_form:
+        type: basic
+        options:
+          submit_button: Apply
+          reset_button: false
+          reset_button_label: Reset
+          exposed_sorts_label: 'Sort by'
+          expose_sort_order: true
+          sort_asc_label: Asc
+          sort_desc_label: Desc
+      pager:
+        type: full
+        options:
+          items_per_page: 10
+          offset: 0
+          id: 0
+          total_pages: null
+          expose:
+            items_per_page: false
+            items_per_page_label: 'Items per page'
+            items_per_page_options: '5, 10, 25, 50'
+            items_per_page_options_all: false
+            items_per_page_options_all_label: '- All -'
+            offset: false
+            offset_label: Offset
+          tags:
+            previous: '‹ previous'
+            next: 'next ›'
+            first: '« first'
+            last: 'last »'
+          quantity: 9
+      style:
+        type: default
+      row:
+        type: fields
+        options:
+          default_field_elements: true
+          inline: {  }
+          separator: ''
+          hide_empty: false
+      fields:
+        field_link:
+          id: field_link
+          table: node__field_link
+          field: field_link
+          relationship: none
+          group_type: group
+          admin_label: ''
+          label: ''
+          exclude: false
+          alter:
+            alter_text: true
+            text: "Formated: {{ field_link }}<br />\nRaw uri: {{ field_link__uri }}<br />\nRaw title: {{ field_link__title }}<br />\nRaw options: {{ field_link__options }}."
+            make_link: false
+            path: '{{ field_link__uri }}'
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: false
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          click_sort_column: uri
+          type: link
+          settings:
+            trim_length: 80
+            url_only: false
+            url_plain: false
+            rel: '0'
+            target: '0'
+          group_column: ''
+          group_columns: {  }
+          group_rows: true
+          delta_limit: 0
+          delta_offset: 0
+          delta_reversed: false
+          delta_first_last: false
+          multi_type: separator
+          separator: ', '
+          field_api_classes: false
+          plugin_id: field
+      filters:
+        status:
+          value: '1'
+          table: node_field_data
+          field: status
+          plugin_id: boolean
+          entity_type: node
+          entity_field: status
+          id: status
+          expose:
+            operator: ''
+          group: 1
+      sorts:
+        created:
+          id: created
+          table: node_field_data
+          field: created
+          order: DESC
+          entity_type: node
+          entity_field: created
+          plugin_id: date
+          relationship: none
+          group_type: group
+          admin_label: ''
+          exposed: false
+          expose:
+            label: ''
+          granularity: second
+      title: link
+      header: {  }
+      footer: {  }
+      empty: {  }
+      relationships: {  }
+      arguments: {  }
+      display_extenders: {  }
+    cache_metadata:
+      contexts:
+        - 'languages:language_content'
+        - 'languages:language_interface'
+        - url.query_args
+        - 'user.node_grants:view'
+        - user.permissions
+      cacheable: false
+  page_1:
+    display_plugin: page
+    id: page_1
+    display_title: Page
+    position: 1
+    display_options:
+      display_extenders: {  }
+      path: test_link_tokens
+    cache_metadata:
+      contexts:
+        - 'languages:language_content'
+        - 'languages:language_interface'
+        - url.query_args
+        - 'user.node_grants:view'
+        - user.permissions
+      cacheable: false

core/modules/link/tests/src/Functional/LinkFieldTest.php

@@ -0,0 +1,639 @@
+<?php
+
+namespace Drupal\Tests\link\Functional;
+
+use Drupal\Component\Utility\Html;
+use Drupal\Component\Utility\Unicode;
+use Drupal\Core\Url;
+use Drupal\entity_test\Entity\EntityTest;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\link\LinkItemInterface;
+use Drupal\Tests\BrowserTestBase;
+use Drupal\field\Entity\FieldStorageConfig;
+
+/**
+ * Tests link field widgets and formatters.
+ *
+ * @group link
+ */
+class LinkFieldTest extends BrowserTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = ['entity_test', 'link', 'node'];
+
+  /**
+   * A field to use in this test class.
+   *
+   * @var \Drupal\field\Entity\FieldStorageConfig
+   */
+  protected $fieldStorage;
+
+  /**
+   * The instance used in this test class.
+   *
+   * @var \Drupal\field\Entity\FieldConfig
+   */
+  protected $field;
+
+  protected function setUp() {
+    parent::setUp();
+
+    $this->drupalLogin($this->drupalCreateUser([
+      'view test entity',
+      'administer entity_test content',
+      'link to any page',
+    ]));
+  }
+
+  /**
+   * Tests link field URL validation.
+   */
+  public function testURLValidation() {
+    $field_name = Unicode::strtolower($this->randomMachineName());
+    // Create a field with settings to validate.
+    $this->fieldStorage = FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'type' => 'link',
+    ]);
+    $this->fieldStorage->save();
+    $this->field = FieldConfig::create([
+      'field_storage' => $this->fieldStorage,
+      'bundle' => 'entity_test',
+      'settings' => [
+        'title' => DRUPAL_DISABLED,
+        'link_type' => LinkItemInterface::LINK_GENERIC,
+      ],
+    ]);
+    $this->field->save();
+    entity_get_form_display('entity_test', 'entity_test', 'default')
+      ->setComponent($field_name, [
+        'type' => 'link_default',
+        'settings' => [
+          'placeholder_url' => 'http://example.com',
+        ],
+      ])
+      ->save();
+    entity_get_display('entity_test', 'entity_test', 'full')
+      ->setComponent($field_name, [
+        'type' => 'link',
+      ])
+      ->save();
+
+    // Display creation form.
+    $this->drupalGet('entity_test/add');
+    $this->assertFieldByName("{$field_name}[0][uri]", '', 'Link URL field is displayed');
+    $this->assertRaw('placeholder="http://example.com"');
+
+    // Create a path alias.
+    \Drupal::service('path.alias_storage')->save('/admin', '/a/path/alias');
+
+    // Create a node to test the link widget.
+    $node = $this->drupalCreateNode();
+
+    // Create an entity with restricted view access.
+    $entity_test_no_label_access = EntityTest::create([
+      'name' => 'forbid_access',
+    ]);
+    $entity_test_no_label_access->save();
+
+    // Define some valid URLs (keys are the entered values, values are the
+    // strings displayed to the user).
+    $valid_external_entries = [
+      'http://www.example.com/' => 'http://www.example.com/',
+      // Strings within parenthesis without leading space char.
+      'http://www.example.com/strings_(string_within_parenthesis)' => 'http://www.example.com/strings_(string_within_parenthesis)',
+      // Numbers within parenthesis without leading space char.
+      'http://www.example.com/numbers_(9999)' => 'http://www.example.com/numbers_(9999)',
+    ];
+    $valid_internal_entries = [
+      '/entity_test/add' => '/entity_test/add',
+      '/a/path/alias' => '/a/path/alias',
+
+      // Front page, with query string and fragment.
+      '/' => '&lt;front&gt;',
+      '/?example=llama' => '&lt;front&gt;?example=llama',
+      '/#example' => '&lt;front&gt;#example',
+
+      // @todo '<front>' is valid input for BC reasons, may be removed by
+      //   https://www.drupal.org/node/2421941
+      '<front>' => '&lt;front&gt;',
+      '<front>#example' => '&lt;front&gt;#example',
+      '<front>?example=llama' => '&lt;front&gt;?example=llama',
+
+      // Query string and fragment.
+      '?example=llama' => '?example=llama',
+      '#example' => '#example',
+
+      // Entity reference autocomplete value.
+      $node->label() . ' (1)' => $node->label() . ' (1)',
+      // Entity URI displayed as ER autocomplete value when displayed in a form.
+      'entity:node/1' => $node->label() . ' (1)',
+      // URI for an entity that exists, but is not accessible by the user.
+      'entity:entity_test/' . $entity_test_no_label_access->id() => '- Restricted access - (' . $entity_test_no_label_access->id() . ')',
+      // URI for an entity that doesn't exist, but with a valid ID.
+      'entity:user/999999' => 'entity:user/999999',
+    ];
+
+    // Define some invalid URLs.
+    $validation_error_1 = "The path '@link_path' is invalid.";
+    $validation_error_2 = 'Manually entered paths should start with /, ? or #.';
+    $validation_error_3 = "The path '@link_path' is inaccessible.";
+    $invalid_external_entries = [
+      // Invalid protocol
+      'invalid://not-a-valid-protocol' => $validation_error_1,
+      // Missing host name
+      'http://' => $validation_error_1,
+    ];
+    $invalid_internal_entries = [
+      'no-leading-slash' => $validation_error_2,
+      'entity:non_existing_entity_type/yar' => $validation_error_1,
+      // URI for an entity that doesn't exist, with an invalid ID.
+      'entity:user/invalid-parameter' => $validation_error_1,
+    ];
+
+    // Test external and internal URLs for 'link_type' = LinkItemInterface::LINK_GENERIC.
+    $this->assertValidEntries($field_name, $valid_external_entries + $valid_internal_entries);
+    $this->assertInvalidEntries($field_name, $invalid_external_entries + $invalid_internal_entries);
+
+    // Test external URLs for 'link_type' = LinkItemInterface::LINK_EXTERNAL.
+    $this->field->setSetting('link_type', LinkItemInterface::LINK_EXTERNAL);
+    $this->field->save();
+    $this->assertValidEntries($field_name, $valid_external_entries);
+    $this->assertInvalidEntries($field_name, $valid_internal_entries + $invalid_external_entries);
+
+    // Test external URLs for 'link_type' = LinkItemInterface::LINK_INTERNAL.
+    $this->field->setSetting('link_type', LinkItemInterface::LINK_INTERNAL);
+    $this->field->save();
+    $this->assertValidEntries($field_name, $valid_internal_entries);
+    $this->assertInvalidEntries($field_name, $valid_external_entries + $invalid_internal_entries);
+
+    // Ensure that users with 'link to any page', don't apply access checking.
+    $this->drupalLogin($this->drupalCreateUser([
+      'view test entity',
+      'administer entity_test content',
+    ]));
+    $this->assertValidEntries($field_name, ['/entity_test/add' => '/entity_test/add']);
+    $this->assertInValidEntries($field_name, ['/admin' => $validation_error_3]);
+  }
+
+  /**
+   * Asserts that valid URLs can be submitted.
+   *
+   * @param string $field_name
+   *   The field name.
+   * @param array $valid_entries
+   *   An array of valid URL entries.
+   */
+  protected function assertValidEntries($field_name, array $valid_entries) {
+    foreach ($valid_entries as $uri => $string) {
+      $edit = [
+        "{$field_name}[0][uri]" => $uri,
+      ];
+      $this->drupalPostForm('entity_test/add', $edit, t('Save'));
+      preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+      $id = $match[1];
+      $this->assertText(t('entity_test @id has been created.', ['@id' => $id]));
+      $this->assertRaw($string);
+    }
+  }
+
+  /**
+   * Asserts that invalid URLs cannot be submitted.
+   *
+   * @param string $field_name
+   *   The field name.
+   * @param array $invalid_entries
+   *   An array of invalid URL entries.
+   */
+  protected function assertInvalidEntries($field_name, array $invalid_entries) {
+    foreach ($invalid_entries as $invalid_value => $error_message) {
+      $edit = [
+        "{$field_name}[0][uri]" => $invalid_value,
+      ];
+      $this->drupalPostForm('entity_test/add', $edit, t('Save'));
+      $this->assertText(t($error_message, ['@link_path' => $invalid_value]));
+    }
+  }
+
+  /**
+   * Tests the link title settings of a link field.
+   */
+  public function testLinkTitle() {
+    $field_name = Unicode::strtolower($this->randomMachineName());
+    // Create a field with settings to validate.
+    $this->fieldStorage = FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'type' => 'link',
+    ]);
+    $this->fieldStorage->save();
+    $this->field = FieldConfig::create([
+      'field_storage' => $this->fieldStorage,
+      'bundle' => 'entity_test',
+      'label' => 'Read more about this entity',
+      'settings' => [
+        'title' => DRUPAL_OPTIONAL,
+        'link_type' => LinkItemInterface::LINK_GENERIC,
+      ],
+    ]);
+    $this->field->save();
+    entity_get_form_display('entity_test', 'entity_test', 'default')
+      ->setComponent($field_name, [
+        'type' => 'link_default',
+        'settings' => [
+          'placeholder_url' => 'http://example.com',
+          'placeholder_title' => 'Enter the text for this link',
+        ],
+      ])
+      ->save();
+    entity_get_display('entity_test', 'entity_test', 'full')
+      ->setComponent($field_name, [
+        'type' => 'link',
+        'label' => 'hidden',
+      ])
+      ->save();
+
+    // Verify that the link text field works according to the field setting.
+    foreach ([DRUPAL_DISABLED, DRUPAL_REQUIRED, DRUPAL_OPTIONAL] as $title_setting) {
+      // Update the link title field setting.
+      $this->field->setSetting('title', $title_setting);
+      $this->field->save();
+
+      // Display creation form.
+      $this->drupalGet('entity_test/add');
+      // Assert label is shown.
+      $this->assertText('Read more about this entity');
+      $this->assertFieldByName("{$field_name}[0][uri]", '', 'URL field found.');
+      $this->assertRaw('placeholder="http://example.com"');
+
+      if ($title_setting === DRUPAL_DISABLED) {
+        $this->assertNoFieldByName("{$field_name}[0][title]", '', 'Link text field not found.');
+        $this->assertNoRaw('placeholder="Enter the text for this link"');
+      }
+      else {
+        $this->assertRaw('placeholder="Enter the text for this link"');
+
+        $this->assertFieldByName("{$field_name}[0][title]", '', 'Link text field found.');
+        if ($title_setting === DRUPAL_REQUIRED) {
+          // Verify that the link text is required, if the URL is non-empty.
+          $edit = [
+            "{$field_name}[0][uri]" => 'http://www.example.com',
+          ];
+          $this->drupalPostForm(NULL, $edit, t('Save'));
+          $this->assertText(t('@name field is required.', ['@name' => t('Link text')]));
+
+          // Verify that the link text is not required, if the URL is empty.
+          $edit = [
+            "{$field_name}[0][uri]" => '',
+          ];
+          $this->drupalPostForm(NULL, $edit, t('Save'));
+          $this->assertNoText(t('@name field is required.', ['@name' => t('Link text')]));
+
+          // Verify that a URL and link text meets requirements.
+          $this->drupalGet('entity_test/add');
+          $edit = [
+            "{$field_name}[0][uri]" => 'http://www.example.com',
+            "{$field_name}[0][title]" => 'Example',
+          ];
+          $this->drupalPostForm(NULL, $edit, t('Save'));
+          $this->assertNoText(t('@name field is required.', ['@name' => t('Link text')]));
+        }
+      }
+    }
+
+    // Verify that a link without link text is rendered using the URL as text.
+    $value = 'http://www.example.com/';
+    $edit = [
+      "{$field_name}[0][uri]" => $value,
+      "{$field_name}[0][title]" => '',
+    ];
+    $this->drupalPostForm(NULL, $edit, t('Save'));
+    preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+    $this->assertText(t('entity_test @id has been created.', ['@id' => $id]));
+
+    $output = $this->renderTestEntity($id);
+    $expected_link = (string) \Drupal::l($value, Url::fromUri($value));
+    $this->assertContains($expected_link, $output);
+
+    // Verify that a link with text is rendered using the link text.
+    $title = $this->randomMachineName();
+    $edit = [
+      "{$field_name}[0][title]" => $title,
+    ];
+    $this->drupalPostForm("entity_test/manage/$id/edit", $edit, t('Save'));
+    $this->assertText(t('entity_test @id has been updated.', ['@id' => $id]));
+
+    $output = $this->renderTestEntity($id);
+    $expected_link = (string) \Drupal::l($title, Url::fromUri($value));
+    $this->assertContains($expected_link, $output);
+  }
+
+  /**
+   * Tests the default 'link' formatter.
+   */
+  public function testLinkFormatter() {
+    $field_name = Unicode::strtolower($this->randomMachineName());
+    // Create a field with settings to validate.
+    $this->fieldStorage = FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'type' => 'link',
+      'cardinality' => 3,
+    ]);
+    $this->fieldStorage->save();
+    FieldConfig::create([
+      'field_storage' => $this->fieldStorage,
+      'label' => 'Read more about this entity',
+      'bundle' => 'entity_test',
+      'settings' => [
+        'title' => DRUPAL_OPTIONAL,
+        'link_type' => LinkItemInterface::LINK_GENERIC,
+      ],
+    ])->save();
+    entity_get_form_display('entity_test', 'entity_test', 'default')
+      ->setComponent($field_name, [
+        'type' => 'link_default',
+      ])
+      ->save();
+    $display_options = [
+      'type' => 'link',
+      'label' => 'hidden',
+    ];
+    entity_get_display('entity_test', 'entity_test', 'full')
+      ->setComponent($field_name, $display_options)
+      ->save();
+
+    // Create an entity with three link field values:
+    // - The first field item uses a URL only.
+    // - The second field item uses a URL and link text.
+    // - The third field item uses a fragment-only URL with text.
+    // For consistency in assertion code below, the URL is assigned to the title
+    // variable for the first field.
+    $this->drupalGet('entity_test/add');
+    $url1 = 'http://www.example.com/content/articles/archive?author=John&year=2012#com';
+    $url2 = 'http://www.example.org/content/articles/archive?author=John&year=2012#org';
+    $url3 = '#net';
+    $title1 = $url1;
+    // Intentionally contains an ampersand that needs sanitization on output.
+    $title2 = 'A very long & strange example title that could break the nice layout of the site';
+    $title3 = 'Fragment only';
+    $edit = [
+      "{$field_name}[0][uri]" => $url1,
+      // Note that $title1 is not submitted.
+      "{$field_name}[0][title]" => '',
+      "{$field_name}[1][uri]" => $url2,
+      "{$field_name}[1][title]" => $title2,
+      "{$field_name}[2][uri]" => $url3,
+      "{$field_name}[2][title]" => $title3,
+    ];
+    // Assert label is shown.
+    $this->assertText('Read more about this entity');
+    $this->drupalPostForm(NULL, $edit, t('Save'));
+    preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+    $this->assertText(t('entity_test @id has been created.', ['@id' => $id]));
+
+    // Verify that the link is output according to the formatter settings.
+    // Not using generatePermutations(), since that leads to 32 cases, which
+    // would not test actual link field formatter functionality but rather
+    // the link generator and options/attributes. Only 'url_plain' has a
+    // dependency on 'url_only', so we have a total of ~10 cases.
+    $options = [
+      'trim_length' => [NULL, 6],
+      'rel' => [NULL, 'nofollow'],
+      'target' => [NULL, '_blank'],
+      'url_only' => [
+        ['url_only' => FALSE],
+        ['url_only' => FALSE, 'url_plain' => TRUE],
+        ['url_only' => TRUE],
+        ['url_only' => TRUE, 'url_plain' => TRUE],
+      ],
+    ];
+    foreach ($options as $setting => $values) {
+      foreach ($values as $new_value) {
+        // Update the field formatter settings.
+        if (!is_array($new_value)) {
+          $display_options['settings'] = [$setting => $new_value];
+        }
+        else {
+          $display_options['settings'] = $new_value;
+        }
+        entity_get_display('entity_test', 'entity_test', 'full')
+          ->setComponent($field_name, $display_options)
+          ->save();
+
+        $output = $this->renderTestEntity($id);
+        switch ($setting) {
+          case 'trim_length':
+            $url = $url1;
+            $title = isset($new_value) ? Unicode::truncate($title1, $new_value, FALSE, TRUE) : $title1;
+            $this->assertContains('<a href="' . Html::escape($url) . '">' . Html::escape($title) . '</a>', $output);
+
+            $url = $url2;
+            $title = isset($new_value) ? Unicode::truncate($title2, $new_value, FALSE, TRUE) : $title2;
+            $this->assertContains('<a href="' . Html::escape($url) . '">' . Html::escape($title) . '</a>', $output);
+
+            $url = $url3;
+            $title = isset($new_value) ? Unicode::truncate($title3, $new_value, FALSE, TRUE) : $title3;
+            $this->assertContains('<a href="' . Html::escape($url) . '">' . Html::escape($title) . '</a>', $output);
+            break;
+
+          case 'rel':
+            $rel = isset($new_value) ? ' rel="' . $new_value . '"' : '';
+            $this->assertContains('<a href="' . Html::escape($url1) . '"' . $rel . '>' . Html::escape($title1) . '</a>', $output);
+            $this->assertContains('<a href="' . Html::escape($url2) . '"' . $rel . '>' . Html::escape($title2) . '</a>', $output);
+            $this->assertContains('<a href="' . Html::escape($url3) . '"' . $rel . '>' . Html::escape($title3) . '</a>', $output);
+            break;
+
+          case 'target':
+            $target = isset($new_value) ? ' target="' . $new_value . '"' : '';
+            $this->assertContains('<a href="' . Html::escape($url1) . '"' . $target . '>' . Html::escape($title1) . '</a>', $output);
+            $this->assertContains('<a href="' . Html::escape($url2) . '"' . $target . '>' . Html::escape($title2) . '</a>', $output);
+            $this->assertContains('<a href="' . Html::escape($url3) . '"' . $target . '>' . Html::escape($title3) . '</a>', $output);
+            break;
+
+          case 'url_only':
+            // In this case, $new_value is an array.
+            if (!$new_value['url_only']) {
+              $this->assertContains('<a href="' . Html::escape($url1) . '">' . Html::escape($title1) . '</a>', $output);
+              $this->assertContains('<a href="' . Html::escape($url2) . '">' . Html::escape($title2) . '</a>', $output);
+              $this->assertContains('<a href="' . Html::escape($url3) . '">' . Html::escape($title3) . '</a>', $output);
+            }
+            else {
+              if (empty($new_value['url_plain'])) {
+                $this->assertContains('<a href="' . Html::escape($url1) . '">' . Html::escape($url1) . '</a>', $output);
+                $this->assertContains('<a href="' . Html::escape($url2) . '">' . Html::escape($url2) . '</a>', $output);
+                $this->assertContains('<a href="' . Html::escape($url3) . '">' . Html::escape($url3) . '</a>', $output);
+              }
+              else {
+                $this->assertNotContains('<a href="' . Html::escape($url1) . '">' . Html::escape($url1) . '</a>', $output);
+                $this->assertNotContains('<a href="' . Html::escape($url2) . '">' . Html::escape($url2) . '</a>', $output);
+                $this->assertNotContains('<a href="' . Html::escape($url3) . '">' . Html::escape($url3) . '</a>', $output);
+                $this->assertContains(Html::escape($url1), $output);
+                $this->assertContains(Html::escape($url2), $output);
+                $this->assertContains(Html::escape($url3), $output);
+              }
+            }
+            break;
+        }
+      }
+    }
+  }
+
+  /**
+   * Tests the 'link_separate' formatter.
+   *
+   * This test is mostly the same as testLinkFormatter(), but they cannot be
+   * merged, since they involve different configuration and output.
+   */
+  public function testLinkSeparateFormatter() {
+    $field_name = Unicode::strtolower($this->randomMachineName());
+    // Create a field with settings to validate.
+    $this->fieldStorage = FieldStorageConfig::create([
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'type' => 'link',
+      'cardinality' => 3,
+    ]);
+    $this->fieldStorage->save();
+    FieldConfig::create([
+      'field_storage' => $this->fieldStorage,
+      'bundle' => 'entity_test',
+      'settings' => [
+        'title' => DRUPAL_OPTIONAL,
+        'link_type' => LinkItemInterface::LINK_GENERIC,
+      ],
+    ])->save();
+    $display_options = [
+      'type' => 'link_separate',
+      'label' => 'hidden',
+    ];
+    entity_get_form_display('entity_test', 'entity_test', 'default')
+      ->setComponent($field_name, [
+        'type' => 'link_default',
+      ])
+      ->save();
+    entity_get_display('entity_test', 'entity_test', 'full')
+      ->setComponent($field_name, $display_options)
+      ->save();
+
+    // Create an entity with three link field values:
+    // - The first field item uses a URL only.
+    // - The second field item uses a URL and link text.
+    // - The third field item uses a fragment-only URL with text.
+    // For consistency in assertion code below, the URL is assigned to the title
+    // variable for the first field.
+    $this->drupalGet('entity_test/add');
+    $url1 = 'http://www.example.com/content/articles/archive?author=John&year=2012#com';
+    $url2 = 'http://www.example.org/content/articles/archive?author=John&year=2012#org';
+    $url3 = '#net';
+    // Intentionally contains an ampersand that needs sanitization on output.
+    $title2 = 'A very long & strange example title that could break the nice layout of the site';
+    $title3 = 'Fragment only';
+    $edit = [
+      "{$field_name}[0][uri]" => $url1,
+      "{$field_name}[1][uri]" => $url2,
+      "{$field_name}[1][title]" => $title2,
+      "{$field_name}[2][uri]" => $url3,
+      "{$field_name}[2][title]" => $title3,
+    ];
+    $this->drupalPostForm(NULL, $edit, t('Save'));
+    preg_match('|entity_test/manage/(\d+)|', $this->getUrl(), $match);
+    $id = $match[1];
+    $this->assertText(t('entity_test @id has been created.', ['@id' => $id]));
+
+    // Verify that the link is output according to the formatter settings.
+    $options = [
+      'trim_length' => [NULL, 6],
+      'rel' => [NULL, 'nofollow'],
+      'target' => [NULL, '_blank'],
+    ];
+    foreach ($options as $setting => $values) {
+      foreach ($values as $new_value) {
+        // Update the field formatter settings.
+        $display_options['settings'] = [$setting => $new_value];
+        entity_get_display('entity_test', 'entity_test', 'full')
+          ->setComponent($field_name, $display_options)
+          ->save();
+
+        $output = $this->renderTestEntity($id);
+        switch ($setting) {
+          case 'trim_length':
+            $url = $url1;
+            $url_title = isset($new_value) ? Unicode::truncate($url, $new_value, FALSE, TRUE) : $url;
+            $expected = '<div class="link-item">';
+            $expected .= '<div class="link-url"><a href="' . Html::escape($url) . '">' . Html::escape($url_title) . '</a></div>';
+            $expected .= '</div>';
+            $this->assertContains($expected, $output);
+
+            $url = $url2;
+            $url_title = isset($new_value) ? Unicode::truncate($url, $new_value, FALSE, TRUE) : $url;
+            $title = isset($new_value) ? Unicode::truncate($title2, $new_value, FALSE, TRUE) : $title2;
+            $expected = '<div class="link-item">';
+            $expected .= '<div class="link-title">' . Html::escape($title) . '</div>';
+            $expected .= '<div class="link-url"><a href="' . Html::escape($url) . '">' . Html::escape($url_title) . '</a></div>';
+            $expected .= '</div>';
+            $this->assertContains($expected, $output);
+
+            $url = $url3;
+            $url_title = isset($new_value) ? Unicode::truncate($url, $new_value, FALSE, TRUE) : $url;
+            $title = isset($new_value) ? Unicode::truncate($title3, $new_value, FALSE, TRUE) : $title3;
+            $expected = '<div class="link-item">';
+            $expected .= '<div class="link-title">' . Html::escape($title) . '</div>';
+            $expected .= '<div class="link-url"><a href="' . Html::escape($url) . '">' . Html::escape($url_title) . '</a></div>';
+            $expected .= '</div>';
+            $this->assertContains($expected, $output);
+            break;
+
+          case 'rel':
+            $rel = isset($new_value) ? ' rel="' . $new_value . '"' : '';
+            $this->assertContains('<div class="link-url"><a href="' . Html::escape($url1) . '"' . $rel . '>' . Html::escape($url1) . '</a></div>', $output);
+            $this->assertContains('<div class="link-url"><a href="' . Html::escape($url2) . '"' . $rel . '>' . Html::escape($url2) . '</a></div>', $output);
+            $this->assertContains('<div class="link-url"><a href="' . Html::escape($url3) . '"' . $rel . '>' . Html::escape($url3) . '</a></div>', $output);
+            break;
+
+          case 'target':
+            $target = isset($new_value) ? ' target="' . $new_value . '"' : '';
+            $this->assertContains('<div class="link-url"><a href="' . Html::escape($url1) . '"' . $target . '>' . Html::escape($url1) . '</a></div>', $output);
+            $this->assertContains('<div class="link-url"><a href="' . Html::escape($url2) . '"' . $target . '>' . Html::escape($url2) . '</a></div>', $output);
+            $this->assertContains('<div class="link-url"><a href="' . Html::escape($url3) . '"' . $target . '>' . Html::escape($url3) . '</a></div>', $output);
+            break;
+        }
+      }
+    }
+  }
+
+  /**
+   * Renders a test_entity and returns the output.
+   *
+   * @param int $id
+   *   The test_entity ID to render.
+   * @param string $view_mode
+   *   (optional) The view mode to use for rendering.
+   * @param bool $reset
+   *   (optional) Whether to reset the entity_test storage cache. Defaults to
+   *   TRUE to simplify testing.
+   *
+   * @return string
+   *   The rendered HTML output.
+   */
+  protected function renderTestEntity($id, $view_mode = 'full', $reset = TRUE) {
+    if ($reset) {
+      $this->container->get('entity.manager')->getStorage('entity_test')->resetCache([$id]);
+    }
+    $entity = EntityTest::load($id);
+    $display = entity_get_display($entity->getEntityTypeId(), $entity->bundle(), $view_mode);
+    $content = $display->build($entity);
+    $output = \Drupal::service('renderer')->renderRoot($content);
+    $output = (string) $output;
+    $this->verbose($output);
+    return $output;
+  }
+
+}

core/modules/link/tests/src/Functional/LinkFieldUITest.php

@@ -0,0 +1,92 @@
+<?php
+
+namespace Drupal\Tests\link\Functional;
+
+use Drupal\Component\Utility\Unicode;
+use Drupal\field_ui\Tests\FieldUiTestTrait;
+use Drupal\link\LinkItemInterface;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Tests link field UI functionality.
+ *
+ * @group link
+ */
+class LinkFieldUITest extends BrowserTestBase {
+
+  use FieldUiTestTrait;
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = ['node', 'link', 'field_ui', 'block'];
+
+  /**
+   * A user that can edit content types.
+   *
+   * @var \Drupal\user\UserInterface
+   */
+  protected $adminUser;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->adminUser = $this->drupalCreateUser(['administer content types', 'administer node fields', 'administer node display']);
+    $this->drupalLogin($this->adminUser);
+    $this->drupalPlaceBlock('system_breadcrumb_block');
+  }
+
+  /**
+   * Tests the link field UI.
+   */
+  public function testFieldUI() {
+    // Add a content type.
+    $type = $this->drupalCreateContentType();
+    $type_path = 'admin/structure/types/manage/' . $type->id();
+    $add_path = 'node/add/' . $type->id();
+
+    // Add a link field to the newly-created type. It defaults to allowing both
+    // internal and external links.
+    $label = $this->randomMachineName();
+    $field_name = Unicode::strtolower($label);
+    $this->fieldUIAddNewField($type_path, $field_name, $label, 'link');
+
+    // Load the formatter page to check that the settings summary does not
+    // generate warnings.
+    // @todo Mess with the formatter settings a bit here.
+    $this->drupalGet("$type_path/display");
+    $this->assertText(t('Link text trimmed to @limit characters', ['@limit' => 80]));
+
+    // Test the help text displays when the link field allows both internal and
+    // external links.
+    $this->drupalLogin($this->drupalCreateUser(['create ' . $type->id() . ' content']));
+    $this->drupalGet($add_path);
+    $this->assertRaw('You can also enter an internal path such as <em class="placeholder">/node/add</em> or an external URL such as <em class="placeholder">http://example.com</em>.');
+
+    // Log in an admin to set up the next content type.
+    $this->drupalLogin($this->adminUser);
+
+    // Add a different content type.
+    $type = $this->drupalCreateContentType();
+    $type_path = 'admin/structure/types/manage/' . $type->id();
+    $add_path = 'node/add/' . $type->id();
+
+    // Add a link field to the newly-created type. Specify it must allow
+    // external only links.
+    $label = $this->randomMachineName();
+    $field_name = Unicode::strtolower($label);
+    $field_edit = ['settings[link_type]' => LinkItemInterface::LINK_EXTERNAL];
+    $this->fieldUIAddNewField($type_path, $field_name, $label, 'link', [], $field_edit);
+
+    // Test the help text displays when link allows only external links.
+    $this->drupalLogin($this->drupalCreateUser(['create ' . $type->id() . ' content']));
+    $this->drupalGet($add_path);
+    $this->assertRaw('This must be an external URL such as <em class="placeholder">http://example.com</em>.');
+  }
+
+}

core/modules/link/tests/src/Kernel/LinkItemTest.php

@@ -0,0 +1,177 @@
+<?php
+
+namespace Drupal\Tests\link\Kernel;
+
+use Drupal\Component\Utility\UrlHelper;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Field\FieldItemInterface;
+use Drupal\Core\Url;
+use Drupal\entity_test\Entity\EntityTest;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\Tests\field\Kernel\FieldKernelTestBase;
+use Drupal\link\LinkItemInterface;
+
+/**
+ * Tests the new entity API for the link field type.
+ *
+ * @group link
+ */
+class LinkItemTest extends FieldKernelTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = ['link'];
+
+  protected function setUp() {
+    parent::setUp();
+
+    // Create a generic, external, and internal link fields for validation.
+    FieldStorageConfig::create([
+      'field_name' => 'field_test',
+      'entity_type' => 'entity_test',
+      'type' => 'link',
+    ])->save();
+    FieldConfig::create([
+      'entity_type' => 'entity_test',
+      'field_name' => 'field_test',
+      'bundle' => 'entity_test',
+      'settings' => ['link_type' => LinkItemInterface::LINK_GENERIC],
+    ])->save();
+    FieldStorageConfig::create([
+      'field_name' => 'field_test_external',
+      'entity_type' => 'entity_test',
+      'type' => 'link',
+    ])->save();
+    FieldConfig::create([
+      'entity_type' => 'entity_test',
+      'field_name' => 'field_test_external',
+      'bundle' => 'entity_test',
+      'settings' => ['link_type' => LinkItemInterface::LINK_EXTERNAL],
+    ])->save();
+    FieldStorageConfig::create([
+      'field_name' => 'field_test_internal',
+      'entity_type' => 'entity_test',
+      'type' => 'link',
+    ])->save();
+    FieldConfig::create([
+      'entity_type' => 'entity_test',
+      'field_name' => 'field_test_internal',
+      'bundle' => 'entity_test',
+      'settings' => ['link_type' => LinkItemInterface::LINK_INTERNAL],
+    ])->save();
+  }
+
+  /**
+   * Tests using entity fields of the link field type.
+   */
+  public function testLinkItem() {
+    // Create entity.
+    $entity = EntityTest::create();
+    $url = 'https://www.drupal.org?test_param=test_value';
+    $parsed_url = UrlHelper::parse($url);
+    $title = $this->randomMachineName();
+    $class = $this->randomMachineName();
+    $entity->field_test->uri = $parsed_url['path'];
+    $entity->field_test->title = $title;
+    $entity->field_test->first()->get('options')->set('query', $parsed_url['query']);
+    $entity->field_test->first()->get('options')->set('attributes', ['class' => $class]);
+    $this->assertEquals([
+      'query' => $parsed_url['query'],
+      'attributes' => [
+        'class' => $class,
+      ],
+      'external' => TRUE,
+    ], $entity->field_test->first()->getUrl()->getOptions());
+    $entity->name->value = $this->randomMachineName();
+    $entity->save();
+
+    // Verify that the field value is changed.
+    $id = $entity->id();
+    $entity = EntityTest::load($id);
+    $this->assertTrue($entity->field_test instanceof FieldItemListInterface, 'Field implements interface.');
+    $this->assertTrue($entity->field_test[0] instanceof FieldItemInterface, 'Field item implements interface.');
+    $this->assertEqual($entity->field_test->uri, $parsed_url['path']);
+    $this->assertEqual($entity->field_test[0]->uri, $parsed_url['path']);
+    $this->assertEqual($entity->field_test->title, $title);
+    $this->assertEqual($entity->field_test[0]->title, $title);
+    $this->assertEqual($entity->field_test->options['attributes']['class'], $class);
+    $this->assertEqual($entity->field_test->options['query'], $parsed_url['query']);
+
+    // Update only the entity name property to check if the link field data will
+    // remain intact.
+    $entity->name->value = $this->randomMachineName();
+    $entity->save();
+    $id = $entity->id();
+    $entity = EntityTest::load($id);
+    $this->assertEqual($entity->field_test->uri, $parsed_url['path']);
+    $this->assertEqual($entity->field_test->options['attributes']['class'], $class);
+    $this->assertEqual($entity->field_test->options['query'], $parsed_url['query']);
+
+    // Verify changing the field value.
+    $new_url = 'https://www.drupal.org';
+    $new_title = $this->randomMachineName();
+    $new_class = $this->randomMachineName();
+    $entity->field_test->uri = $new_url;
+    $entity->field_test->title = $new_title;
+    $entity->field_test->first()->get('options')->set('query', NULL);
+    $entity->field_test->first()->get('options')->set('attributes', ['class' => $new_class]);
+    $this->assertEqual($entity->field_test->uri, $new_url);
+    $this->assertEqual($entity->field_test->title, $new_title);
+    $this->assertEqual($entity->field_test->options['attributes']['class'], $new_class);
+    $this->assertNull($entity->field_test->options['query']);
+
+    // Read changed entity and assert changed values.
+    $entity->save();
+    $entity = EntityTest::load($id);
+    $this->assertEqual($entity->field_test->uri, $new_url);
+    $this->assertEqual($entity->field_test->title, $new_title);
+    $this->assertEqual($entity->field_test->options['attributes']['class'], $new_class);
+
+    // Check that if we only set uri the default values for title and options
+    // are also initialized.
+    $entity->field_test = ['uri' => 'internal:/node/add'];
+    $this->assertEqual($entity->field_test->uri, 'internal:/node/add');
+    $this->assertNull($entity->field_test->title);
+    $this->assertIdentical($entity->field_test->options, []);
+
+    // Check that if set uri and serialize options then the default values are
+    // properly initialized.
+    $entity->field_test = [
+      'uri' => 'internal:/node/add',
+      'options' => serialize(['query' => NULL]),
+    ];
+    $this->assertEqual($entity->field_test->uri, 'internal:/node/add');
+    $this->assertNull($entity->field_test->title);
+    $this->assertNull($entity->field_test->options['query']);
+
+    // Check that if we set the direct value of link field it correctly set the
+    // uri and the default values of the field.
+    $entity->field_test = 'internal:/node/add';
+    $this->assertEqual($entity->field_test->uri, 'internal:/node/add');
+    $this->assertNull($entity->field_test->title);
+    $this->assertIdentical($entity->field_test->options, []);
+
+    // Check that setting options to NULL does not trigger an error when
+    // calling getUrl();
+    $entity->field_test->options = NULL;
+    $this->assertInstanceOf(Url::class, $entity->field_test[0]->getUrl());
+
+    // Check that setting LinkItem value NULL doesn't generate any error or
+    // warning.
+    $entity->field_test[0] = NULL;
+    $this->assertNull($entity->field_test[0]->getValue());
+
+    // Test the generateSampleValue() method for generic, external, and internal
+    // link types.
+    $entity = EntityTest::create();
+    $entity->field_test->generateSampleItems();
+    $entity->field_test_external->generateSampleItems();
+    $entity->field_test_internal->generateSampleItems();
+    $this->entityValidateAndSave($entity);
+  }
+
+}

core/modules/link/tests/src/Unit/Plugin/Validation/Constraint/LinkAccessConstraintValidatorTest.php

@@ -0,0 +1,96 @@
+<?php
+
+namespace Drupal\Tests\link\Unit\Plugin\Validation\Constraint;
+
+use Drupal\link\Plugin\Validation\Constraint\LinkAccessConstraint;
+use Drupal\link\Plugin\Validation\Constraint\LinkAccessConstraintValidator;
+use Drupal\Tests\UnitTestCase;
+use Symfony\Component\Validator\Context\ExecutionContextInterface;
+
+/**
+ * Tests the LinkAccessConstraintValidator validator.
+ *
+ * @coversDefaultClass \Drupal\link\Plugin\Validation\Constraint\LinkAccessConstraintValidator
+ * @group validation
+ */
+class LinkAccessConstraintValidatorTest extends UnitTestCase {
+
+  /**
+   * Tests the \Drupal\link\Plugin\Validation\Constraint\LinkAccessConstraintValidator::validate()
+   * method.
+   *
+   * @param \Drupal\link\LinkItemInterface $value
+   *   The link item.
+   * @param \Drupal\Core\Session\AccountProxyInterface $user
+   *   The user account.
+   * @param bool $valid
+   *   A boolean indicating if the combination is expected to be valid.
+   *
+   * @covers ::validate
+   * @dataProvider providerValidate
+   */
+  public function testValidate($value, $user, $valid) {
+    $context = $this->getMock(ExecutionContextInterface::class);
+
+    if ($valid) {
+      $context->expects($this->never())
+        ->method('addViolation');
+    }
+    else {
+      $context->expects($this->once())
+        ->method('addViolation');
+    }
+
+    $constraint = new LinkAccessConstraint();
+
+    $validate = new LinkAccessConstraintValidator($user);
+    $validate->initialize($context);
+    $validate->validate($value, $constraint);
+  }
+
+  /**
+   * Data provider for LinkAccessConstraintValidator::validate().
+   *
+   * @return array
+   *   An array of tests, matching the parameter inputs for testValidate.
+   *
+   * @see \Drupal\Tests\link\LinkAccessConstraintValidatorTest::validate()
+   */
+  public function providerValidate() {
+    $data = [];
+
+    $cases = [
+      ['may_link_any_page' => TRUE, 'url_access' => TRUE, 'valid' => TRUE],
+      ['may_link_any_page' => TRUE, 'url_access' => FALSE, 'valid' => TRUE],
+      ['may_link_any_page' => FALSE, 'url_access' => TRUE, 'valid' => TRUE],
+      ['may_link_any_page' => FALSE, 'url_access' => FALSE, 'valid' => FALSE],
+    ];
+
+    foreach ($cases as $case) {
+      // Mock a Url object that returns a boolean indicating user access.
+      $url = $this->getMockBuilder('Drupal\Core\Url')
+        ->disableOriginalConstructor()
+        ->getMock();
+      $url->expects($this->once())
+        ->method('access')
+        ->willReturn($case['url_access']);
+      // Mock a link object that returns the URL object.
+      $link = $this->getMock('Drupal\link\LinkItemInterface');
+      $link->expects($this->any())
+        ->method('getUrl')
+        ->willReturn($url);
+      // Mock a user object that returns a boolean indicating user access to all
+      // links.
+      $user = $this->getMock('Drupal\Core\Session\AccountProxyInterface');
+      $user->expects($this->any())
+        ->method('hasPermission')
+        ->with($this->equalTo('link to any page'))
+        ->willReturn($case['may_link_any_page']);
+
+      $data[] = [$link, $user, $case['valid']];
+    }
+
+    return $data;
+  }
+
+}

core/modules/link/tests/src/Unit/Plugin/Validation/Constraint/LinkExternalProtocolsConstraintValidatorTest.php

@@ -0,0 +1,112 @@
+<?php
+
+namespace Drupal\Tests\link\Unit\Plugin\Validation\Constraint;
+
+use Drupal\Component\Utility\UrlHelper;
+use Drupal\Core\Url;
+use Drupal\link\Plugin\Validation\Constraint\LinkExternalProtocolsConstraint;
+use Drupal\link\Plugin\Validation\Constraint\LinkExternalProtocolsConstraintValidator;
+use Drupal\Tests\UnitTestCase;
+use Symfony\Component\Validator\Context\ExecutionContextInterface;
+
+/**
+ * @coversDefaultClass \Drupal\link\Plugin\Validation\Constraint\LinkExternalProtocolsConstraintValidator
+ * @group Link
+ */
+class LinkExternalProtocolsConstraintValidatorTest extends UnitTestCase {
+
+  /**
+   * @covers ::validate
+   * @dataProvider providerValidate
+   */
+  public function testValidate($value, $valid) {
+    $context = $this->getMock(ExecutionContextInterface::class);
+
+    if ($valid) {
+      $context->expects($this->never())
+        ->method('addViolation');
+    }
+    else {
+      $context->expects($this->once())
+        ->method('addViolation');
+    }
+
+    // Setup some more allowed protocols.
+    UrlHelper::setAllowedProtocols(['http', 'https', 'magnet']);
+
+    $constraint = new LinkExternalProtocolsConstraint();
+
+    $validator = new LinkExternalProtocolsConstraintValidator();
+    $validator->initialize($context);
+    $validator->validate($value, $constraint);
+  }
+
+  /**
+   * Data provider for ::testValidate
+   */
+  public function providerValidate() {
+    $data = [];
+
+    // Test allowed protocols.
+    $data[] = ['http://www.drupal.org', TRUE];
+    $data[] = ['https://www.drupal.org', TRUE];
+    $data[] = ['magnet:?xt=urn:sha1:YNCKHTQCWBTRNJIV4WNAE52SJUQCZO5C', TRUE];
+
+    // Invalid protocols.
+    $data[] = ['ftp://ftp.funet.fi/pub/standards/RFC/rfc959.txt', FALSE];
+
+    foreach ($data as &$single_data) {
+      $url = Url::fromUri($single_data[0]);
+      $link = $this->getMock('Drupal\link\LinkItemInterface');
+      $link->expects($this->any())
+        ->method('getUrl')
+        ->willReturn($url);
+      $single_data[0] = $link;
+    }
+
+    return $data;
+  }
+
+  /**
+   * @covers ::validate
+   *
+   * @see \Drupal\Core\Url::fromUri
+   */
+  public function testValidateWithMalformedUri() {
+    $link = $this->getMock('Drupal\link\LinkItemInterface');
+    $link->expects($this->any())
+      ->method('getUrl')
+      ->willThrowException(new \InvalidArgumentException());
+
+    $context = $this->getMock(ExecutionContextInterface::class);
+    $context->expects($this->never())
+      ->method('addViolation');
+
+    $constraint = new LinkExternalProtocolsConstraint();
+
+    $validator = new LinkExternalProtocolsConstraintValidator();
+    $validator->initialize($context);
+    $validator->validate($link, $constraint);
+  }
+
+  /**
+   * @covers ::validate
+   */
+  public function testValidateIgnoresInternalUrls() {
+    $link = $this->getMock('Drupal\link\LinkItemInterface');
+    $link->expects($this->any())
+      ->method('getUrl')
+      ->willReturn(Url::fromRoute('example.test'));
+
+    $context = $this->getMock(ExecutionContextInterface::class);
+    $context->expects($this->never())
+      ->method('addViolation');
+
+    $constraint = new LinkExternalProtocolsConstraint();
+
+    $validator = new LinkExternalProtocolsConstraintValidator();
+    $validator->initialize($context);
+    $validator->validate($link, $constraint);
+  }
+
+}

core/modules/link/tests/src/Unit/Plugin/Validation/Constraint/LinkNotExistingInternalConstraintValidatorTest.php

@@ -0,0 +1,109 @@
+<?php
+
+namespace Drupal\Tests\link\Unit\Plugin\Validation\Constraint;
+
+use Drupal\Core\Url;
+use Drupal\link\Plugin\Validation\Constraint\LinkNotExistingInternalConstraint;
+use Drupal\link\Plugin\Validation\Constraint\LinkNotExistingInternalConstraintValidator;
+use Drupal\Tests\UnitTestCase;
+use Symfony\Component\Routing\Exception\RouteNotFoundException;
+use Symfony\Component\Validator\Context\ExecutionContextInterface;
+
+/**
+ * @coversDefaultClass \Drupal\link\Plugin\Validation\Constraint\LinkNotExistingInternalConstraintValidator
+ * @group Link
+ */
+class LinkNotExistingInternalConstraintValidatorTest extends UnitTestCase {
+
+  /**
+   * @covers ::validate
+   * @dataProvider providerValidate
+   */
+  public function testValidate($value, $valid) {
+    $context = $this->getMock(ExecutionContextInterface::class);
+
+    if ($valid) {
+      $context->expects($this->never())
+        ->method('addViolation');
+    }
+    else {
+      $context->expects($this->once())
+        ->method('addViolation');
+    }
+
+
+    $constraint = new LinkNotExistingInternalConstraint();
+
+    $validator = new LinkNotExistingInternalConstraintValidator();
+    $validator->initialize($context);
+    $validator->validate($value, $constraint);
+  }
+
+  /**
+   * Data provider for ::testValidate
+   */
+  public function providerValidate() {
+    $data = [];
+
+    // External URL
+    $data[] = [Url::fromUri('https://www.drupal.org'), TRUE];
+
+    // Existing routed URL.
+    $url = Url::fromRoute('example.existing_route');
+
+    $url_generator = $this->getMock('Drupal\Core\Routing\UrlGeneratorInterface');
+    $url_generator->expects($this->any())
+      ->method('generateFromRoute')
+      ->with('example.existing_route', [], [])
+      ->willReturn('/example/existing');
+    $url->setUrlGenerator($url_generator);
+
+    $data[] = [$url, TRUE];
+
+    // Not existing routed URL.
+    $url = Url::fromRoute('example.not_existing_route');
+
+    $url_generator = $this->getMock('Drupal\Core\Routing\UrlGeneratorInterface');
+    $url_generator->expects($this->any())
+      ->method('generateFromRoute')
+      ->with('example.not_existing_route', [], [])
+      ->willThrowException(new RouteNotFoundException());
+    $url->setUrlGenerator($url_generator);
+
+    $data[] = [$url, FALSE];
+
+    foreach ($data as &$single_data) {
+      $link = $this->getMock('Drupal\link\LinkItemInterface');
+      $link->expects($this->any())
+        ->method('getUrl')
+        ->willReturn($single_data[0]);
+
+      $single_data[0] = $link;
+    }
+
+    return $data;
+  }
+
+  /**
+   * @covers ::validate
+   *
+   * @see \Drupal\Core\Url::fromUri
+   */
+  public function testValidateWithMalformedUri() {
+    $link = $this->getMock('Drupal\link\LinkItemInterface');
+    $link->expects($this->any())
+      ->method('getUrl')
+      ->willThrowException(new \InvalidArgumentException());
+
+    $context = $this->getMock(ExecutionContextInterface::class);
+    $context->expects($this->never())
+      ->method('addViolation');
+
+    $constraint = new LinkNotExistingInternalConstraint();
+
+    $validator = new LinkNotExistingInternalConstraintValidator();
+    $validator->initialize($context);
+    $validator->validate($link, $constraint);
+  }
+
+}

core/modules/link/tests/src/Unit/Plugin/migrate/process/d6/CckLinkTest.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace Drupal\Tests\link\Unit\Plugin\migrate\process\d6;
+
+use Drupal\link\Plugin\migrate\process\d6\CckLink;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @group Link
+ */
+class CckLinkTest extends UnitTestCase {
+
+  /**
+   * Test the url transformations in the CckLink process plugin.
+   *
+   * @dataProvider canonicalizeUriDataProvider
+   */
+  public function testCanonicalizeUri($url, $expected) {
+    $link_plugin = new CckLink([], '', [], $this->getMock('\Drupal\migrate\Plugin\MigrationInterface'));
+    $transformed = $link_plugin->transform([
+      'url' => $url,
+      'title' => '',
+      'attributes' => serialize([]),
+    ], $this->getMock('\Drupal\migrate\MigrateExecutableInterface'), $this->getMockBuilder('\Drupal\migrate\Row')->disableOriginalConstructor()->getMock(), NULL);
+    $this->assertEquals($expected, $transformed['uri']);
+  }
+
+  /**
+   * Data provider for testCanonicalizeUri.
+   */
+  public function canonicalizeUriDataProvider() {
+    return [
+      'Simple front-page' => [
+        '<front>',
+        'internal:/',
+      ],
+      'Front page with query' => [
+        '<front>?query=1',
+        'internal:/?query=1',
+      ],
+      'No leading forward slash' => [
+        'node/10',
+        'internal:/node/10',
+      ],
+      'Leading forward slash' => [
+        '/node/10',
+        'internal:/node/10',
+      ],
+      'Existing scheme' => [
+        'scheme:test',
+        'scheme:test',
+      ],
+    ];
+  }
+
+}