diff --git a/core/modules/block/custom_block/lib/Drupal/custom_block/Tests/CustomBlockFieldTest.php b/core/modules/block/custom_block/lib/Drupal/custom_block/Tests/CustomBlockFieldTest.php
index 0185523..da5ac4f 100644
--- a/core/modules/block/custom_block/lib/Drupal/custom_block/Tests/CustomBlockFieldTest.php
+++ b/core/modules/block/custom_block/lib/Drupal/custom_block/Tests/CustomBlockFieldTest.php
@@ -25,14 +25,14 @@ class CustomBlockFieldTest extends CustomBlockTestBase {
   /**
    * The created field.
    *
-   * @var array
+   * @var \Drupal\field\Plugin\Core\Entity\Field
    */
   protected $field;
 
   /**
-   * The created instance
+   * The created instance.
    *
-   * @var array
+   * @var \Drupal\field\Plugin\Core\Entity\FieldInstance
    */
   protected $instance;
 
diff --git a/core/modules/contact/lib/Drupal/contact/Tests/Views/ContactFieldsTest.php b/core/modules/contact/lib/Drupal/contact/Tests/Views/ContactFieldsTest.php
index e7c7aa1..166a64b 100644
--- a/core/modules/contact/lib/Drupal/contact/Tests/Views/ContactFieldsTest.php
+++ b/core/modules/contact/lib/Drupal/contact/Tests/Views/ContactFieldsTest.php
@@ -24,7 +24,7 @@ class ContactFieldsTest extends ViewTestBase {
   /**
    * Contains the field definition array attached to contact used for this test.
    *
-   * @var array
+   * @var \Drupal\field\Plugin\Core\Entity\Field
    */
   protected $field;
 
diff --git a/core/modules/datetime/lib/Drupal/datetime/Tests/DatetimeFieldTest.php b/core/modules/datetime/lib/Drupal/datetime/Tests/DatetimeFieldTest.php
index 7c56c3e..43ff047 100644
--- a/core/modules/datetime/lib/Drupal/datetime/Tests/DatetimeFieldTest.php
+++ b/core/modules/datetime/lib/Drupal/datetime/Tests/DatetimeFieldTest.php
@@ -26,10 +26,17 @@ class DatetimeFieldTest extends WebTestBase {
   /**
    * A field to use in this test class.
    *
-   * @var \Drupal\Core\Datetime\DrupalDateTime
+   * @var \Drupal\field\Plugin\Core\Entity\Field
    */
   protected $field;
 
+  /**
+   * A field to use in this test class.
+   *
+   * @var \Drupal\field\Plugin\Core\Entity\FieldInstance
+   */
+  protected $instance;
+
   public static function getInfo() {
     return array(
       'name'  => 'Datetime Field',
@@ -89,8 +96,8 @@ function testDateField() {
     // Display creation form.
     $this->drupalGet('entity_test/add');
     $langcode = Language::LANGCODE_NOT_SPECIFIED;
-    $this->assertFieldByName("$field_name[$langcode][0][value][date]", '', 'Date element found.');
-    $this->assertNoFieldByName("$field_name[$langcode][0][value][time]", '', 'Time element not found.');
+    $this->assertFieldByName("{$field_name}[$langcode][0][value][date]", '', 'Date element found.');
+    $this->assertNoFieldByName("{$field_name}[$langcode][0][value][time]", '', 'Time element not found.');
 
     // Submit a valid date and ensure it is accepted.
     $value = '2012-12-31 00:00:00';
@@ -102,7 +109,7 @@ function testDateField() {
     $edit = array(
       'user_id' => 1,
       'name' => $this->randomName(),
-      "$field_name[$langcode][0][value][date]" => $date->format($date_format),
+      "{$field_name}[$langcode][0][value][date]" => $date->format($date_format),
     );
     $this->drupalPost(NULL, $edit, t('Save'));
     preg_match('|entity_test/manage/(\d+)/edit|', $this->url, $match);
@@ -160,8 +167,8 @@ function testDatetimeField() {
     // Display creation form.
     $this->drupalGet('entity_test/add');
     $langcode = Language::LANGCODE_NOT_SPECIFIED;
-    $this->assertFieldByName("$field_name[$langcode][0][value][date]", '', 'Date element found.');
-    $this->assertFieldByName("$field_name[$langcode][0][value][time]", '', 'Time element found.');
+    $this->assertFieldByName("{$field_name}[$langcode][0][value][date]", '', 'Date element found.');
+    $this->assertFieldByName("{$field_name}[$langcode][0][value][time]", '', 'Time element found.');
 
     // Submit a valid date and ensure it is accepted.
     $value = '2012-12-31 00:00:00';
@@ -173,8 +180,8 @@ function testDatetimeField() {
     $edit = array(
       'user_id' => 1,
       'name' => $this->randomName(),
-      "$field_name[$langcode][0][value][date]" => $date->format($date_format),
-      "$field_name[$langcode][0][value][time]" => $date->format($time_format),
+      "{$field_name}[$langcode][0][value][date]" => $date->format($date_format),
+      "{$field_name}[$langcode][0][value][time]" => $date->format($time_format),
     );
     $this->drupalPost(NULL, $edit, t('Save'));
     preg_match('|entity_test/manage/(\d+)/edit|', $this->url, $match);
@@ -267,7 +274,7 @@ function testDatelistWidget() {
     // Add the ampm indicator since we are testing 12 hour time.
     $date_value['ampm'] = 'am';
     foreach ($date_value as $part => $value) {
-      $edit["$field_name[$langcode][0][value][$part]"] = $value;
+      $edit["{$field_name}[$langcode][0][value][$part]"] = $value;
     }
 
     $this->drupalPost(NULL, $edit, t('Save'));
@@ -308,8 +315,8 @@ function testDefaultValue() {
     // it may be a few seconds between the time the comparison date is created
     // and the form date, so we just test the date and that the time is not
     // empty.
-    $this->assertFieldByName("$field_name[$langcode][0][value][date]", $date->format($date_format), 'Date element found.');
-    $this->assertNoFieldByName("$field_name[$langcode][0][value][time]", '', 'Time element found.');
+    $this->assertFieldByName("{$field_name}[$langcode][0][value][date]", $date->format($date_format), 'Date element found.');
+    $this->assertNoFieldByName("{$field_name}[$langcode][0][value][time]", '', 'Time element found.');
 
     // Set the default value to 'blank'.
     $this->instance->settings['default_value'] = 'blank';
@@ -321,8 +328,8 @@ function testDefaultValue() {
     $this->drupalGet('entity_test/add');
 
     // See that no date is set.
-    $this->assertFieldByName("$field_name[$langcode][0][value][date]", '', 'Date element found.');
-    $this->assertFieldByName("$field_name[$langcode][0][value][time]", '', 'Time element found.');
+    $this->assertFieldByName("{$field_name}[$langcode][0][value][date]", '', 'Date element found.');
+    $this->assertFieldByName("{$field_name}[$langcode][0][value][time]", '', 'Time element found.');
   }
 
   /**
@@ -338,38 +345,38 @@ function testInvalidField() {
     // Display creation form.
     $this->drupalGet('entity_test/add');
     $langcode = Language::LANGCODE_NOT_SPECIFIED;
-    $this->assertFieldByName("$field_name[$langcode][0][value][date]", '', 'Date element found.');
-    $this->assertFieldByName("$field_name[$langcode][0][value][time]", '', 'Time element found.');
+    $this->assertFieldByName("{$field_name}[$langcode][0][value][date]", '', 'Date element found.');
+    $this->assertFieldByName("{$field_name}[$langcode][0][value][time]", '', 'Time element found.');
 
     // Submit invalid dates and ensure they is not accepted.
     $date_value = '';
     $edit = array(
-      "$field_name[$langcode][0][value][date]" => $date_value,
-      "$field_name[$langcode][0][value][time]" => '12:00:00',
+      "{$field_name}[$langcode][0][value][date]" => $date_value,
+      "{$field_name}[$langcode][0][value][time]" => '12:00:00',
     );
     $this->drupalPost(NULL, $edit, t('Save'));
     $this->assertText('date is invalid', 'Empty date value has been caught.');
 
     $date_value = 'aaaa-12-01';
     $edit = array(
-      "$field_name[$langcode][0][value][date]" => $date_value,
-      "$field_name[$langcode][0][value][time]" => '00:00:00',
+      "{$field_name}[$langcode][0][value][date]" => $date_value,
+      "{$field_name}[$langcode][0][value][time]" => '00:00:00',
     );
     $this->drupalPost(NULL, $edit, t('Save'));
     $this->assertText('date is invalid', format_string('Invalid year value %date has been caught.', array('%date' => $date_value)));
 
     $date_value = '2012-75-01';
     $edit = array(
-      "$field_name[$langcode][0][value][date]" => $date_value,
-      "$field_name[$langcode][0][value][time]" => '00:00:00',
+      "{$field_name}[$langcode][0][value][date]" => $date_value,
+      "{$field_name}[$langcode][0][value][time]" => '00:00:00',
     );
     $this->drupalPost(NULL, $edit, t('Save'));
     $this->assertText('date is invalid', format_string('Invalid month value %date has been caught.', array('%date' => $date_value)));
 
     $date_value = '2012-12-99';
     $edit = array(
-      "$field_name[$langcode][0][value][date]" => $date_value,
-      "$field_name[$langcode][0][value][time]" => '00:00:00',
+      "{$field_name}[$langcode][0][value][date]" => $date_value,
+      "{$field_name}[$langcode][0][value][time]" => '00:00:00',
     );
     $this->drupalPost(NULL, $edit, t('Save'));
     $this->assertText('date is invalid', format_string('Invalid day value %date has been caught.', array('%date' => $date_value)));
@@ -377,8 +384,8 @@ function testInvalidField() {
     $date_value = '2012-12-01';
     $time_value = '';
     $edit = array(
-      "$field_name[$langcode][0][value][date]" => $date_value,
-      "$field_name[$langcode][0][value][time]" => $time_value,
+      "{$field_name}[$langcode][0][value][date]" => $date_value,
+      "{$field_name}[$langcode][0][value][time]" => $time_value,
     );
     $this->drupalPost(NULL, $edit, t('Save'));
     $this->assertText('date is invalid', 'Empty time value has been caught.');
@@ -386,8 +393,8 @@ function testInvalidField() {
     $date_value = '2012-12-01';
     $time_value = '49:00:00';
     $edit = array(
-      "$field_name[$langcode][0][value][date]" => $date_value,
-      "$field_name[$langcode][0][value][time]" => $time_value,
+      "{$field_name}[$langcode][0][value][date]" => $date_value,
+      "{$field_name}[$langcode][0][value][time]" => $time_value,
     );
     $this->drupalPost(NULL, $edit, t('Save'));
     $this->assertText('date is invalid', format_string('Invalid hour value %time has been caught.', array('%time' => $time_value)));
@@ -395,8 +402,8 @@ function testInvalidField() {
     $date_value = '2012-12-01';
     $time_value = '12:99:00';
     $edit = array(
-      "$field_name[$langcode][0][value][date]" => $date_value,
-      "$field_name[$langcode][0][value][time]" => $time_value,
+      "{$field_name}[$langcode][0][value][date]" => $date_value,
+      "{$field_name}[$langcode][0][value][time]" => $time_value,
     );
     $this->drupalPost(NULL, $edit, t('Save'));
     $this->assertText('date is invalid', format_string('Invalid minute value %time has been caught.', array('%time' => $time_value)));
@@ -404,8 +411,8 @@ function testInvalidField() {
     $date_value = '2012-12-01';
     $time_value = '12:15:99';
     $edit = array(
-      "$field_name[$langcode][0][value][date]" => $date_value,
-      "$field_name[$langcode][0][value][time]" => $time_value,
+      "{$field_name}[$langcode][0][value][date]" => $date_value,
+      "{$field_name}[$langcode][0][value][time]" => $time_value,
     );
     $this->drupalPost(NULL, $edit, t('Save'));
     $this->assertText('date is invalid', format_string('Invalid second value %time has been caught.', array('%time' => $time_value)));
diff --git a/core/modules/email/lib/Drupal/email/Tests/EmailFieldTest.php b/core/modules/email/lib/Drupal/email/Tests/EmailFieldTest.php
index 2192cf3..af75fdb 100644
--- a/core/modules/email/lib/Drupal/email/Tests/EmailFieldTest.php
+++ b/core/modules/email/lib/Drupal/email/Tests/EmailFieldTest.php
@@ -22,6 +22,20 @@ class EmailFieldTest extends WebTestBase {
    */
   public static $modules = array('node', 'entity_test', 'email', 'field_ui');
 
+  /**
+   * A field to use in this test class.
+   *
+   * @var \Drupal\field\Plugin\Core\Entity\Field
+   */
+  protected $field;
+
+  /**
+   * A field to use in this test class.
+   *
+   * @var \Drupal\field\Plugin\Core\Entity\FieldInstance
+   */
+  protected $instance;
+
   public static function getInfo() {
     return array(
       'name'  => 'E-mail field',
@@ -78,7 +92,7 @@ function testEmailField() {
     // Display creation form.
     $this->drupalGet('entity_test/add');
     $langcode = Language::LANGCODE_NOT_SPECIFIED;
-    $this->assertFieldByName("$field_name[$langcode][0][value]", '', 'Widget found.');
+    $this->assertFieldByName("{$field_name}[$langcode][0][value]", '', 'Widget found.');
     $this->assertRaw('placeholder="example@example.com"');
 
     // Submit a valid e-mail address and ensure it is accepted.
@@ -86,7 +100,7 @@ function testEmailField() {
     $edit = array(
       'user_id' => 1,
       'name' => $this->randomName(),
-      "$field_name[$langcode][0][value]" => $value,
+      "{$field_name}[$langcode][0][value]" => $value,
     );
     $this->drupalPost(NULL, $edit, t('Save'));
     preg_match('|entity_test/manage/(\d+)/edit|', $this->url, $match);