diff --git a/apps/showcase/static/js/vue.js b/apps/showcase/static/js/vue.js
index 4ef7ff1b0..919aa1251 100644
--- a/apps/showcase/static/js/vue.js
+++ b/apps/showcase/static/js/vue.js
@@ -1,6 +1,6 @@
 /*!
- * Vue.js v2.6.10
- * (c) 2014-2019 Evan You
+ * Vue.js v2.6.12
+ * (c) 2014-2020 Evan You
  * Released under the MIT License.
  */
 (function (global, factory) {
@@ -1969,7 +1969,7 @@
     isUsingMicroTask = true;
   } else if (typeof setImmediate !== 'undefined' && isNative(setImmediate)) {
     // Fallback to setImmediate.
-    // Techinically it leverages the (macro) task queue,
+    // Technically it leverages the (macro) task queue,
     // but it is still a better choice than setTimeout.
     timerFunc = function () {
       setImmediate(flushCallbacks);
@@ -2058,7 +2058,7 @@
       warn(
         "Property \"" + key + "\" must be accessed with \"$data." + key + "\" because " +
         'properties starting with "$" or "_" are not proxied in the Vue instance to ' +
-        'prevent conflicts with Vue internals' +
+        'prevent conflicts with Vue internals. ' +
         'See: https://vuejs.org/v2/api/#data',
         target
       );
@@ -2918,7 +2918,7 @@
       if (typeof key === 'string' && key) {
         baseObj[values[i]] = values[i + 1];
       } else if (key !== '' && key !== null) {
-        // null is a speical value for explicitly removing a binding
+        // null is a special value for explicitly removing a binding
         warn(
           ("Invalid value for dynamic directive argument (expected string or null): " + key),
           this
@@ -3413,6 +3413,12 @@
       ns = (context.$vnode && context.$vnode.ns) || config.getTagNamespace(tag);
       if (config.isReservedTag(tag)) {
         // platform built-in elements
+        if (isDef(data) && isDef(data.nativeOn)) {
+          warn(
+            ("The .native modifier for v-on is only valid on components but it was used on <" + tag + ">."),
+            context
+          );
+        }
         vnode = new VNode(
           config.parsePlatformTagName(tag), data, children,
           undefined, undefined, context
@@ -3538,7 +3544,7 @@
       // render self
       var vnode;
       try {
-        // There's no need to maintain a stack becaues all render fns are called
+        // There's no need to maintain a stack because all render fns are called
         // separately from one another. Nested component's render fns are called
         // when parent component is patched.
         currentRenderingInstance = vm;
@@ -5437,7 +5443,7 @@
     value: FunctionalRenderContext
   });
 
-  Vue.version = '2.6.10';
+  Vue.version = '2.6.12';
 
   /*  */
 
@@ -6110,7 +6116,7 @@
       }
     }
 
-    function removeVnodes (parentElm, vnodes, startIdx, endIdx) {
+    function removeVnodes (vnodes, startIdx, endIdx) {
       for (; startIdx <= endIdx; ++startIdx) {
         var ch = vnodes[startIdx];
         if (isDef(ch)) {
@@ -6221,7 +6227,7 @@
         refElm = isUndef(newCh[newEndIdx + 1]) ? null : newCh[newEndIdx + 1].elm;
         addVnodes(parentElm, refElm, newCh, newStartIdx, newEndIdx, insertedVnodeQueue);
       } else if (newStartIdx > newEndIdx) {
-        removeVnodes(parentElm, oldCh, oldStartIdx, oldEndIdx);
+        removeVnodes(oldCh, oldStartIdx, oldEndIdx);
       }
     }
 
@@ -6313,7 +6319,7 @@
           if (isDef(oldVnode.text)) { nodeOps.setTextContent(elm, ''); }
           addVnodes(elm, null, ch, 0, ch.length - 1, insertedVnodeQueue);
         } else if (isDef(oldCh)) {
-          removeVnodes(elm, oldCh, 0, oldCh.length - 1);
+          removeVnodes(oldCh, 0, oldCh.length - 1);
         } else if (isDef(oldVnode.text)) {
           nodeOps.setTextContent(elm, '');
         }
@@ -6542,7 +6548,7 @@
 
           // destroy old node
           if (isDef(parentElm)) {
-            removeVnodes(parentElm, [oldVnode], 0, 0);
+            removeVnodes([oldVnode], 0, 0);
           } else if (isDef(oldVnode.tag)) {
             invokeDestroyHook(oldVnode);
           }
@@ -7643,7 +7649,7 @@
         // skip the update if old and new VDOM state is the same.
         // `value` is handled separately because the DOM value may be temporarily
         // out of sync with VDOM state due to focus, composition and modifiers.
-        // This  #4521 by skipping the unnecesarry `checked` update.
+        // This  #4521 by skipping the unnecessary `checked` update.
         cur !== oldProps[key]
       ) {
         // some property updates can throw
@@ -9248,7 +9254,7 @@
   var startTagClose = /^\s*(\/?)>/;
   var endTag = new RegExp(("^<\\/" + qnameCapture + "[^>]*>"));
   var doctype = /^<!DOCTYPE [^>]+>/i;
-  // #7298: escape - to avoid being pased as HTML comment when inlined in page
+  // #7298: escape - to avoid being passed as HTML comment when inlined in page
   var comment = /^<!\--/;
   var conditionalComment = /^<!\[/;
 
@@ -9533,7 +9539,7 @@
   /*  */
 
   var onRE = /^@|^v-on:/;
-  var dirRE = /^v-|^@|^:/;
+  var dirRE = /^v-|^@|^:|^#/;
   var forAliasRE = /([\s\S]*?)\s+(?:in|of)\s+([\s\S]*)/;
   var forIteratorRE = /,([^,\}\]]*)(?:,([^,\}\]]*))?$/;
   var stripParensRE = /^\(|\)$/g;
@@ -9888,7 +9894,7 @@
         }
       },
       comment: function comment (text, start, end) {
-        // adding anyting as a sibling to the root node is forbidden
+        // adding anything as a sibling to the root node is forbidden
         // comments should still be allowed, but ignored
         if (currentParent) {
           var child = {
@@ -10157,7 +10163,7 @@
             if (el.parent && !maybeComponent(el.parent)) {
               warn$2(
                 "<template v-slot> can only appear at the root level inside " +
-                "the receiving the component",
+                "the receiving component",
                 el
               );
             }
@@ -10720,7 +10726,7 @@
 
   /*  */
 
-  var fnExpRE = /^([\w$_]+|\([^)]*?\))\s*=>|^function\s*(?:[\w$]+)?\s*\(/;
+  var fnExpRE = /^([\w$_]+|\([^)]*?\))\s*=>|^function(?:\s+[\w$]+)?\s*\(/;
   var fnInvokeRE = /\([^)]*?\);*$/;
   var simplePathRE = /^[A-Za-z_$][\w$]*(?:\.[A-Za-z_$][\w$]*|\['[^']*?']|\["[^"]*?"]|\[\d+]|\[[A-Za-z_$][\w$]*])*$/;
 
@@ -11489,6 +11495,8 @@
             var range = node.rawAttrsMap[name];
             if (name === 'v-for') {
               checkFor(node, ("v-for=\"" + value + "\""), warn, range);
+            } else if (name === 'v-slot' || name[0] === '#') {
+              checkFunctionParameterExpression(value, (name + "=\"" + value + "\""), warn, range);
             } else if (onRE.test(name)) {
               checkEvent(value, (name + "=\"" + value + "\""), warn, range);
             } else {
@@ -11508,9 +11516,9 @@
   }
 
   function checkEvent (exp, text, warn, range) {
-    var stipped = exp.replace(stripStringRE, '');
-    var keywordMatch = stipped.match(unaryOperatorsRE);
-    if (keywordMatch && stipped.charAt(keywordMatch.index - 1) !== '$') {
+    var stripped = exp.replace(stripStringRE, '');
+    var keywordMatch = stripped.match(unaryOperatorsRE);
+    if (keywordMatch && stripped.charAt(keywordMatch.index - 1) !== '$') {
       warn(
         "avoid using JavaScript unary operator as property name: " +
         "\"" + (keywordMatch[0]) + "\" in expression " + (text.trim()),
@@ -11565,6 +11573,19 @@
     }
   }
 
+  function checkFunctionParameterExpression (exp, text, warn, range) {
+    try {
+      new Function(exp, '');
+    } catch (e) {
+      warn(
+        "invalid function parameter expression: " + (e.message) + " in\n\n" +
+        "    " + exp + "\n\n" +
+        "  Raw expression: " + (text.trim()) + "\n",
+        range
+      );
+    }
+  }
+
   /*  */
 
   var range = 2;