Update Composer, update everything

web/core/modules/system/js/system.date.es6.js

@@ -0,0 +1,62 @@
+/**
+ * @file
+ * Provides date format preview feature.
+ */
+
+(function($, Drupal, drupalSettings) {
+  const dateFormats = drupalSettings.dateFormats;
+
+  /**
+   * Display the preview for date format entered.
+   *
+   * @type {Drupal~behavior}
+   *
+   * @prop {Drupal~behaviorAttach} attach
+   *   Attach behavior for previewing date formats on input elements.
+   */
+  Drupal.behaviors.dateFormat = {
+    attach(context) {
+      const $context = $(context);
+      const $source = $context
+        .find('[data-drupal-date-formatter="source"]')
+        .once('dateFormat');
+      const $target = $context
+        .find('[data-drupal-date-formatter="preview"]')
+        .once('dateFormat');
+      const $preview = $target.find('em');
+
+      // All elements have to exist.
+      if (!$source.length || !$target.length) {
+        return;
+      }
+
+      /**
+       * Event handler that replaces date characters with value.
+       *
+       * @param {jQuery.Event} e
+       *   The jQuery event triggered.
+       */
+      function dateFormatHandler(e) {
+        const baseValue = $(e.target).val() || '';
+        const dateString = baseValue.replace(
+          /\\?(.?)/gi,
+          (key, value) => (dateFormats[key] ? dateFormats[key] : value),
+        );
+
+        $preview.html(dateString);
+        $target.toggleClass('js-hide', !dateString.length);
+      }
+
+      /**
+       * On given event triggers the date character replacement.
+       */
+      $source
+        .on(
+          'keyup.dateFormat change.dateFormat input.dateFormat',
+          dateFormatHandler,
+        )
+        // Initialize preview.
+        .trigger('keyup');
+    },
+  };
+})(jQuery, Drupal, drupalSettings);