diff --git a/core/misc/announce.js b/core/misc/announce.js
index 7425a43..cd1ee5b 100644
--- a/core/misc/announce.js
+++ b/core/misc/announce.js
@@ -101,9 +101,9 @@
    * messages. These messages are then joined and append to the aria-live region
    * as one text node.
    *
-   * @param {String} text
+   * @param {string} text
    *   A string to be read by the UA.
-   * @param {String} priority
+   * @param {string} priority
    *   A string to indicate the priority of the message. Can be either
    *   'polite' or 'assertive'.
    *
@@ -119,5 +119,8 @@
       });
       debouncedProcessAnnounce(announcements);
     }
+    else {
+      throw new Error(Drupal.t('"text" passed Drupal.announce must be a string.'));
+    }
   };
 }(Drupal, Drupal.debounce));
diff --git a/core/misc/message.js b/core/misc/message.js
index 9505ad3..50e8ec4 100644
--- a/core/misc/message.js
+++ b/core/misc/message.js
@@ -69,7 +69,7 @@
         text: message,
         type: type || 'status'
       });
-      debouncedProcessMessages(messages);
+      debouncedProcessMessages();
     }
   };
 
@@ -80,12 +80,13 @@
    *   The message context to remove
    * @param {string} type
    *   Message type, can be either 'status', 'error' or 'warning'.
-   *   Default to 'status'
    */
   Drupal.message.remove = function (context, type) {
-    context = context || 'default';
-    type = type || 'status';
-    $('.messages--' + type + '.js-messages-context--' + context).remove();
+    var selector = '.js-messages-context--' + (context || 'default');
+    if (type) {
+      selector = '.messages--' + (type || 'status') + selector;
+    }
+    $(selector).remove();
   };
 
   /**
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 576916f..b38a1c2 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
@@ -19,7 +19,7 @@
         e.preventDefault();
         var type = e.currentTarget.getAttribute('data-type');
         var context = e.currentTarget.getAttribute('data-context');
-        message.add('Msg-' + type + '-' + context, type, context);
+        message.add('Msg-' + context + '-' + type, type, context);
       });
       $('.remove-link').once('remove-msg').on('click', function (e) {
         e.preventDefault();
@@ -30,7 +30,7 @@
       $('.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);
+          message.add('Msg-' + i, 'status', 'context-' + i);
         }
 
       });
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 ce25516..239d4ef 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
@@ -40,6 +40,15 @@ public function messageLinks() {
           ],
         ];
       }
+      $links["remove-$context"] = [
+        'title' => "Remove-$context-all",
+        'url' => Url::fromRoute('js_message_test.links'),
+        'attributes' => [
+          'id' => "remove-$context",
+          'data-context' => $context,
+          'class' => ['remove-link'],
+        ],
+      ];
     }
     $links['show-multi'] = [
       'title' => "Show Multiple",
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Core/JsMessageTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Core/JsMessageTest.php
index 1893879..0387b01 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Core/JsMessageTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Core/JsMessageTest.php
@@ -48,31 +48,48 @@ public function testAddRemoveMessages() {
         $selector = ".messages.messages--$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");
+        $web_assert->elementContains('css', $selector, "Msg-$context-$type");
         // 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");
+        $web_assert->elementContains('css', $selector, "Msg-$context-$type");
         // Click the remove links that should remove the message.
         $this->clickLink("Remove-$context-$type");
         $web_assert->elementNotExists('css', $selector);
       }
     }
 
+    // Test removing all messages of a specific context.
+    $this->clickLink("Show-context1-error");
+    $this->clickLink("Show-context2-error");
+    $this->clickLink("Show-context1-warning");
+    $this->clickLink("Show-context2-warning");
+    $this->waitForMessageElement('warning', 'context2');
+    $this->assertCurrentMessages([
+      'Msg-context1-error',
+      'Msg-context2-error',
+      'Msg-context1-warning',
+      'Msg-context2-warning',
+    ]);
+    $this->clickLink('Remove-context1-all');
+    $web_assert->assertWaitOnAjaxRequest();
+    $this->assertCurrentMessages([
+      'Msg-context2-error',
+      'Msg-context2-warning',
+    ]);
+    $this->clickLink('Remove-context2-all');
+    $this->assertCurrentMessages([]);
+
     // 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');
+    $this->waitForMessageElement('default', 'context-9');
 
-    foreach ($message_divs as $message_div) {
-      /** @var \Behat\Mink\Element\NodeElement $message_div */
-      $this->assertEquals("Msg-$message_number", $message_div->getText());
-      $message_number++;
+    $current_messages = [];
+    for ($i = 0; $i < 10; $i++) {
+      $current_messages[] = "Msg-$i";
     }
+    $this->assertCurrentMessages($current_messages);
   }
 
   /**
@@ -93,4 +110,33 @@ protected function clickAllRemoveLinksExcept($exclude_context, $exclude_type) {
     }
   }
 
+  /**
+   * Asserts that currently shown messages match expected messages.
+   *
+   * @param array $expected_messages
+   *   Expected messages.
+   */
+  private function assertCurrentMessages($expected_messages) {
+    $current_messages = [];
+    $message_divs = $this->getSession()->getPage()->findAll('css', '.messages');
+    foreach ($message_divs as $message_div) {
+      /** @var \Behat\Mink\Element\NodeElement $message_div */
+      $current_messages[] = $message_div->getText();
+    }
+    $this->assertEquals($expected_messages, $current_messages);
+  }
+
+  /**
+   * Waits for an element message to be visible.
+   *
+   * @param string $type
+   *   The type of the message.
+   * @param string $context
+   *   The context of the message.
+   */
+  protected function waitForMessageElement($type, $context) {
+    $last_msg_element = $this->assertSession()->waitForElementVisible('css', ".messages.messages--$type.js-messages.js-messages-context--$context");
+    $this->assertNotEmpty($last_msg_element, "Message element visible.");
+  }
+
 }