diff --git a/core/misc/message.js b/core/misc/message.js
index e7c13b3..9505ad3 100644
--- a/core/misc/message.js
+++ b/core/misc/message.js
@@ -9,6 +9,7 @@
   var messages = [];
   var messagesElement;
   var debouncedProcessMessages;
+  var messageWrapperSelector = '[data-drupal-messages]';
 
   /**
    * Builds a div element with the aria-live attribute and attaches it to the DOM.
@@ -16,49 +17,47 @@
   Drupal.behaviors.drupalMessage = {
     attach: function () {
       if (!messagesElement) {
-        if (!$('[data-drupal-messages]').length) {
+        var $messagesWrapper = $(messageWrapperSelector);
+        if (!$messagesWrapper.length) {
           throw new Error(Drupal.t('There is no element with a [data-drupal-messages] attribute'));
         }
-        messagesElement = $('[data-drupal-messages]')[0];
+        messagesElement = $messagesWrapper[0];
       }
     }
   };
 
+  // Debounce the function in case Drupal.message() is used in a loop.
+  debouncedProcessMessages = debounce(processMessages, 100);
+
   /**
    * Displays all queued messages in one pass instead of one after the other.
    * @see debouncedProcessMessages
    */
   function processMessages() {
     var text = [];
-    var message;
-    var messagesIndex;
-    var messagesLength;
 
-    if (messages.length) {
-      for (messagesIndex = 0, messagesLength = messages.length; messagesIndex < messagesLength; messagesIndex++) {
-        message = messages.pop();
-        text.unshift(Drupal.theme('message', message));
-      }
-      if (text.length) {
-        messagesElement.innerHTML += text.join('');
-      }
+    messages.reverse().forEach(function (message) {
+      text.unshift(Drupal.theme('message', message));
+    });
+    if (text.length) {
+      messagesElement.innerHTML += text.join('');
     }
-  }
+    // Reset the messages array after the messages are processed.
+    messages = [];
 
-  // Debounce the function in case Drupal.message() is used in a loop.
-  debouncedProcessMessages = debounce(processMessages, 100);
+  }
 
   Drupal.message = {};
 
   /**
    * Displays a message on the page.
    *
-   * @param {String} message
+   * @param {string} message
    *   The message to display
-   * @param {String} type
+   * @param {string} type
    *   Message type, can be either 'status', 'error' or 'warning'.
    *   Default to 'status'
-   * @param {String} context
+   * @param {string} context
    *   The context of the message, used for removing messages again.
    */
   Drupal.message.add = function (message, type, context) {
@@ -77,9 +76,9 @@
   /**
    * Removes messages from the page.
    *
-   * @param {String} context
+   * @param {string} context
    *   The message context to remove
-   * @param {String} type
+   * @param {string} type
    *   Message type, can be either 'status', 'error' or 'warning'.
    *   Default to 'status'
    */
@@ -92,14 +91,18 @@
   /**
    * Theme function for a message.
    *
-   * @param {Object} message
-   *   An object with the following keys:
-   *   - {String} text: The message text
-   *   - {String} type: The message type
-   * @return {String}
+   * @param {object} message
+   *   The message object.
+   * @param {string} message.text
+   *   The message text.
+   * @param {string} message.type
+   *   The message type.
+   * @param {string} message.context
+   *   The message context.
+   * @return {string}
    *   A string representing a DOM fragment.
    */
-  Drupal.theme.message = function (message, context) {
+  Drupal.theme.message = function (message) {
     return '<div class="messages messages--' + message.type + ' js-messages js-messages-context--' + message.context + '">' + message.text + '</div>';
   };
 
diff --git a/core/modules/system/tests/modules/js_message_test/js/js_message_test.js b/core/modules/system/tests/modules/js_message_test/js/js_message_test.js
index 4f54544..576916f 100644
--- a/core/modules/system/tests/modules/js_message_test/js/js_message_test.js
+++ b/core/modules/system/tests/modules/js_message_test/js/js_message_test.js
@@ -27,6 +27,13 @@
         var context = e.currentTarget.getAttribute('data-context');
         message.remove(context, type);
       });
+      $('.show-multiple').once('show-msg').on('click', function (e) {
+        e.preventDefault();
+        for (var i = 0; i < 10; i++) {
+          message.add('Msg-' + i, 'default', 'context-' + i);
+        }
+
+      });
     }
   };
 
diff --git a/core/modules/system/tests/modules/js_message_test/js_message_test.libraries.yml b/core/modules/system/tests/modules/js_message_test/js_message_test.libraries.yml
index 33c49e0..53da0f9 100644
--- a/core/modules/system/tests/modules/js_message_test/js_message_test.libraries.yml
+++ b/core/modules/system/tests/modules/js_message_test/js_message_test.libraries.yml
@@ -4,3 +4,4 @@ show_message:
     js/js_message_test.js: {}
   dependencies:
     - core/drupal.message
+    - core/jquery.once
diff --git a/core/modules/system/tests/modules/js_message_test/src/Controller/JSMessageTestController.php b/core/modules/system/tests/modules/js_message_test/src/Controller/JSMessageTestController.php
index 839ef4f..ce25516 100644
--- a/core/modules/system/tests/modules/js_message_test/src/Controller/JSMessageTestController.php
+++ b/core/modules/system/tests/modules/js_message_test/src/Controller/JSMessageTestController.php
@@ -40,8 +40,14 @@ public function messageLinks() {
           ],
         ];
       }
-
     }
+    $links['show-multi'] = [
+      'title' => "Show Multiple",
+      'url' => Url::fromRoute('js_message_test.links'),
+      'attributes' => [
+        'class' => ['show-multiple'],
+      ],
+    ];
     return [
       '#theme' => 'links',
       '#links' => $links,
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Core/JsMessageTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Core/JsMessageTest.php
index fc8746f..1893879 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Core/JsMessageTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Core/JsMessageTest.php
@@ -16,22 +16,79 @@ class JsMessageTest extends JavascriptTestBase {
    */
   public static $modules = ['js_message_test'];
 
+  /**
+   * The possible message contexts.
+   *
+   * @var array
+   *
+   * @see \Drupal\js_message_test\Controller\JSMessageTestController::messageLinks
+   */
+  protected $msgContexts = ['context1', 'context2'];
+
+  /**
+   * The possible message types.
+   *
+   * @var array
+   *
+   * @see \Drupal\js_message_test\Controller\JSMessageTestController::messageLinks
+   */
+  protected $msgTypes = ['status', 'error', 'warning'];
 
-  public function testJSMessages() {
+  /**
+   * Test click on links to show messages and remove messages.
+   */
+  public function testAddRemoveMessages() {
     $web_assert = $this->assertSession();
     $this->drupalGet('js_message_test_link');
     $web_assert->elementExists('css', '[data-drupal-messages]');
-    $contexts = ['context1', 'context2'];
-    $types = ['status', 'error', 'warning'];
-    foreach ($contexts as $context) {
-      foreach ($types as $type) {
+
+    foreach ($this->msgContexts as $context) {
+      foreach ($this->msgTypes as $type) {
         $this->clickLink("Show-$context-$type");
-        $this->getSession()->wait('200');
         $selector = ".messages.messages--$type.js-messages.js-messages-context--$context";
         $msg_element = $web_assert->waitForElementVisible('css', $selector);
         $this->assertNotEmpty($msg_element, "Message element visible: $selector");
         $web_assert->elementContains('css', $selector, "Msg-$type-$context");
-        // @todo Test clicking remove links.
+        // Click all remove links except the one that will remove the message.
+        $this->clickAllRemoveLinksExcept($context, $type);
+        // Confirm the message was not removed.
+        $web_assert->elementContains('css', $selector, "Msg-$type-$context");
+        // Click the remove links that should remove the message.
+        $this->clickLink("Remove-$context-$type");
+        $web_assert->elementNotExists('css', $selector);
+      }
+    }
+
+    // Test adding multiple messages at once.
+    // @see processMessages()
+    $this->clickLink('Show Multiple');
+    $message_number = 0;
+    $last_msg_element = $web_assert->waitForElementVisible('css', '.messages.messages--default.js-messages.js-messages-context--context-9');
+    $this->assertNotEmpty($last_msg_element, "Last message element visible.");
+    $message_divs = $this->getSession()->getPage()->findAll('css', '.messages');
+    $this->assertEquals(10, count($message_divs), 'All messages shown');
+
+    foreach ($message_divs as $message_div) {
+      /** @var \Behat\Mink\Element\NodeElement $message_div */
+      $this->assertEquals("Msg-$message_number", $message_div->getText());
+      $message_number++;
+    }
+  }
+
+  /**
+   * Clicks all remove message links except for combination specified.
+   *
+   * @param string $exclude_context
+   *   The message context to exclude.
+   * @param string $exclude_type
+   *   The message type to exclude.
+   */
+  protected function clickAllRemoveLinksExcept($exclude_context, $exclude_type) {
+    foreach ($this->msgContexts as $context) {
+      foreach ($this->msgTypes as $type) {
+        if ($context !== $exclude_context || $type !== $exclude_type) {
+          $this->clickLink("Remove-$context-$type");
+        }
       }
     }
   }