chore(release): 2.3.1

CHANGELOG.md

@@ -2,6 +2,15 @@
 
 All notable changes to this project will be documented in this file. See [standard-version](https://github.com/conventional-changelog/standard-version) for commit guidelines.
 
+### [2.3.1](https://github.com/nuxt/vue-meta/compare/v2.3.0...v2.3.1) (2019-10-09)
+
+
+### Bug Fixes
+
+* accept and pass options as second arg for generate ([2ce5177](https://github.com/nuxt/vue-meta/commit/2ce5177))
+* still traverse children when metainfo doesnt return object ([#469](https://github.com/nuxt/vue-meta/issues/469)) ([35b7099](https://github.com/nuxt/vue-meta/commit/35b7099))
+* try to detect global mixins adding meta info ([#467](https://github.com/nuxt/vue-meta/issues/467)) ([2231ec1](https://github.com/nuxt/vue-meta/commit/2231ec1))
+
 ## [2.3.0](https://github.com/nuxt/vue-meta/compare/v2.3.0-beta.0...v2.3.0) (2019-10-03)
 
 ## [2.3.0-beta.0](https://github.com/nuxt/vue-meta/compare/v2.2.2...v2.3.0-beta.0) (2019-09-17)

dist/vue-meta.common.js

@@ -1,5 +1,5 @@
 /**
- * vue-meta v2.3.0
+ * vue-meta v2.3.1
  * (c) 2019
  * - Declan de Wet
  * - Sébastien Chopin (@Atinux)
@@ -14,7 +14,7 @@ function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'defau
 
 var deepmerge = _interopDefault(require('deepmerge'));
 
-var version = "2.3.0";
+var version = "2.3.1";
 
 function _typeof(obj) {
   if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") {
@@ -233,6 +233,63 @@ function batchUpdate(callback, timeout) {
   return batchId;
 }
 
+/*
+ * To reduce build size, this file provides simple polyfills without
+ * overly excessive type checking and without modifying
+ * the global Array.prototype
+ * The polyfills are automatically removed in the commonjs build
+ * Also, only files in client/ & shared/ should use these functions
+ * files in server/ still use normal js function
+ */
+function find(array, predicate, thisArg) {
+  if ( !Array.prototype.find) {
+    // idx needs to be a Number, for..in returns string
+    for (var idx = 0; idx < array.length; idx++) {
+      if (predicate.call(thisArg, array[idx], idx, array)) {
+        return array[idx];
+      }
+    }
+
+    return;
+  }
+
+  return array.find(predicate, thisArg);
+}
+function findIndex(array, predicate, thisArg) {
+  if ( !Array.prototype.findIndex) {
+    // idx needs to be a Number, for..in returns string
+    for (var idx = 0; idx < array.length; idx++) {
+      if (predicate.call(thisArg, array[idx], idx, array)) {
+        return idx;
+      }
+    }
+
+    return -1;
+  }
+
+  return array.findIndex(predicate, thisArg);
+}
+function toArray(arg) {
+  if ( !Array.from) {
+    return Array.prototype.slice.call(arg);
+  }
+
+  return Array.from(arg);
+}
+function includes(array, value) {
+  if ( !Array.prototype.includes) {
+    for (var idx in array) {
+      if (array[idx] === value) {
+        return true;
+      }
+    }
+
+    return false;
+  }
+
+  return array.includes(value);
+}
+
 function ensureIsArray(arg, key) {
   if (!key || !isObject(arg)) {
     return isArray(arg) ? arg : [];
@@ -306,11 +363,12 @@ function createMixin(Vue, options) {
       var rootKey = '$root';
       var $root = this[rootKey];
       var $options = this.$options;
+      var devtoolsEnabled = Vue.config.devtools;
       Object.defineProperty(this, '_hasMetaInfo', {
         configurable: true,
         get: function get() {
           // Show deprecation warning once when devtools enabled
-          if (Vue.config.devtools && !$root[rootConfigKey].deprecationWarningShown) {
+          if (devtoolsEnabled && !$root[rootConfigKey].deprecationWarningShown) {
             warn('VueMeta DeprecationWarning: _hasMetaInfo has been deprecated and will be removed in a future version. Please use hasMetaInfo(vm) instead');
             $root[rootConfigKey].deprecationWarningShown = true;
           }
@@ -330,6 +388,20 @@ function createMixin(Vue, options) {
           appId: appId
         };
         appId++;
+
+        if (devtoolsEnabled && $root.$options[options.keyName]) {
+          // use nextTick so the children should be added to $root
+          this.$nextTick(function () {
+            // find the first child that lists fnOptions
+            var child = find($root.$children, function (c) {
+              return c.$vnode && c.$vnode.fnOptions;
+            });
+
+            if (child && child.$vnode.fnOptions[options.keyName]) {
+              warn("VueMeta has detected a possible global mixin which adds a ".concat(options.keyName, " property to all Vue components on the page. This could cause severe performance issues. If possible, use $meta().addApp to add meta information instead"));
+            }
+          });
+        }
       } // to speed up updates we keep track of branches which have a component with vue-meta info defined
       // if _vueMeta = true it has info, if _vueMeta = false a child has info
 
@@ -373,14 +445,18 @@ function createMixin(Vue, options) {
         $root[rootConfigKey].initialized = this.$isServer;
 
         if (!$root[rootConfigKey].initialized) {
-          ensuredPush($options, 'beforeMount', function () {
+          if (!$root[rootConfigKey].initializedSsr) {
-            var $root = this[rootKey]; // if this Vue-app was server rendered, set the appId to 'ssr'
+            $root[rootConfigKey].initializedSsr = true;
-            // only one SSR app per page is supported
+            ensuredPush($options, 'beforeMount', function () {
+              var $root = this; // if this Vue-app was server rendered, set the appId to 'ssr'
+              // only one SSR app per page is supported
+
+              if ($root.$el && $root.$el.nodeType === 1 && $root.$el.hasAttribute('data-server-rendered')) {
+                $root[rootConfigKey].appId = options.ssrAppId;
+              }
+            });
+          } // we use the mounted hook here as on page load
 
-            if ($root.$el && $root.$el.nodeType === 1 && $root.$el.hasAttribute('data-server-rendered')) {
-              $root[rootConfigKey].appId = options.ssrAppId;
-            }
-          }); // we use the mounted hook here as on page load
 
           ensuredPush($options, 'mounted', function () {
             var $root = this[rootKey];
@@ -426,6 +502,7 @@ function createMixin(Vue, options) {
 
 
       if (this.$isServer) {
+        /* istanbul ignore next */
         return;
       } // no need to add this hooks on server side
 
@@ -448,6 +525,7 @@ function createMixin(Vue, options) {
         return;
       }
 
+      delete this._hasMetaInfo;
       this.$nextTick(function () {
         if (!options.waitOnDestroyed || !_this.$el || !_this.$el.offsetParent) {
           triggerUpdate(options, _this.$root, 'destroyed');
@@ -502,49 +580,6 @@ function getOptions(options) {
   return optionsCopy;
 }
 
-/*
- * To reduce build size, this file provides simple polyfills without
- * overly excessive type checking and without modifying
- * the global Array.prototype
- * The polyfills are automatically removed in the commonjs build
- * Also, only files in client/ & shared/ should use these functions
- * files in server/ still use normal js function
- */
-function findIndex(array, predicate, thisArg) {
-  if ( !Array.prototype.findIndex) {
-    // idx needs to be a Number, for..in returns string
-    for (var idx = 0; idx < array.length; idx++) {
-      if (predicate.call(thisArg, array[idx], idx, array)) {
-        return idx;
-      }
-    }
-
-    return -1;
-  }
-
-  return array.findIndex(predicate, thisArg);
-}
-function toArray(arg) {
-  if ( !Array.from) {
-    return Array.prototype.slice.call(arg);
-  }
-
-  return Array.from(arg);
-}
-function includes(array, value) {
-  if ( !Array.prototype.includes) {
-    for (var idx in array) {
-      if (array[idx] === value) {
-        return true;
-      }
-    }
-
-    return false;
-  }
-
-  return array.includes(value);
-}
-
 var serverSequences = [[/&/g, '&amp;'], [/</g, '&lt;'], [/>/g, '&gt;'], [/"/g, '&quot;'], [/'/g, '&#x27;']];
 var clientSequences = [[/&/g, "&"], [/</g, "<"], [/>/g, ">"], [/"/g, "\""], [/'/g, "'"]]; // sanitizes potentially dangerous characters
 
@@ -820,14 +855,13 @@ function getComponentOption(options, component, result) {
     // and set to the computed prop $metaInfo in the mixin
     // using the computed prop should be a small performance increase
     // because Vue caches those internally
-    var data = $metaInfo || $options[keyName]; // ignore data if its not an object, then we keep our previous result
+    var data = $metaInfo || $options[keyName]; // only merge data with result when its an object
+    // eg it could be a function when metaInfo() returns undefined
+    // dueo to the or statement above
 
-    if (!isObject(data)) {
+    if (isObject(data)) {
-      return result;
+      result = merge(result, data, options);
-    } // merge with existing options
+    }
-
-
-    result = merge(result, data, options);
   } // collect & aggregate child options if deep = true
 
 
@@ -1819,8 +1853,8 @@ function install(Vue, options) {
 var index = {
   version: version,
   install: install,
-  generate: function generate$1(metaInfo) {
+  generate: function generate$1(metaInfo, options) {
-    return  generate(metaInfo) ;
+    return  generate(metaInfo, options) ;
   },
   hasMetaInfo: hasMetaInfo
 };

dist/vue-meta.esm.browser.js

@@ -1,5 +1,5 @@
 /**
- * vue-meta v2.3.0
+ * vue-meta v2.3.1
  * (c) 2019
  * - Declan de Wet
  * - Sébastien Chopin (@Atinux)
@@ -10,7 +10,7 @@
 
 import deepmerge from 'deepmerge';
 
-var version = "2.3.0";
+var version = "2.3.1";
 
 function _typeof(obj) {
   if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") {
@@ -190,6 +190,63 @@ function batchUpdate(callback, timeout) {
   return batchId;
 }
 
+/*
+ * To reduce build size, this file provides simple polyfills without
+ * overly excessive type checking and without modifying
+ * the global Array.prototype
+ * The polyfills are automatically removed in the commonjs build
+ * Also, only files in client/ & shared/ should use these functions
+ * files in server/ still use normal js function
+ */
+function find(array, predicate, thisArg) {
+  if ( !Array.prototype.find) {
+    // idx needs to be a Number, for..in returns string
+    for (var idx = 0; idx < array.length; idx++) {
+      if (predicate.call(thisArg, array[idx], idx, array)) {
+        return array[idx];
+      }
+    }
+
+    return;
+  }
+
+  return array.find(predicate, thisArg);
+}
+function findIndex(array, predicate, thisArg) {
+  if ( !Array.prototype.findIndex) {
+    // idx needs to be a Number, for..in returns string
+    for (var idx = 0; idx < array.length; idx++) {
+      if (predicate.call(thisArg, array[idx], idx, array)) {
+        return idx;
+      }
+    }
+
+    return -1;
+  }
+
+  return array.findIndex(predicate, thisArg);
+}
+function toArray(arg) {
+  if ( !Array.from) {
+    return Array.prototype.slice.call(arg);
+  }
+
+  return Array.from(arg);
+}
+function includes(array, value) {
+  if ( !Array.prototype.includes) {
+    for (var idx in array) {
+      if (array[idx] === value) {
+        return true;
+      }
+    }
+
+    return false;
+  }
+
+  return array.includes(value);
+}
+
 function ensureIsArray(arg, key) {
   if (!key || !isObject(arg)) {
     return isArray(arg) ? arg : [];
@@ -263,11 +320,12 @@ function createMixin(Vue, options) {
       var rootKey = '$root';
       var $root = this[rootKey];
       var $options = this.$options;
+      var devtoolsEnabled = Vue.config.devtools;
       Object.defineProperty(this, '_hasMetaInfo', {
         configurable: true,
         get: function get() {
           // Show deprecation warning once when devtools enabled
-          if (Vue.config.devtools && !$root[rootConfigKey].deprecationWarningShown) {
+          if (devtoolsEnabled && !$root[rootConfigKey].deprecationWarningShown) {
             warn('VueMeta DeprecationWarning: _hasMetaInfo has been deprecated and will be removed in a future version. Please use hasMetaInfo(vm) instead');
             $root[rootConfigKey].deprecationWarningShown = true;
           }
@@ -287,6 +345,20 @@ function createMixin(Vue, options) {
           appId: appId
         };
         appId++;
+
+        if (devtoolsEnabled && $root.$options[options.keyName]) {
+          // use nextTick so the children should be added to $root
+          this.$nextTick(function () {
+            // find the first child that lists fnOptions
+            var child = find($root.$children, function (c) {
+              return c.$vnode && c.$vnode.fnOptions;
+            });
+
+            if (child && child.$vnode.fnOptions[options.keyName]) {
+              warn("VueMeta has detected a possible global mixin which adds a ".concat(options.keyName, " property to all Vue components on the page. This could cause severe performance issues. If possible, use $meta().addApp to add meta information instead"));
+            }
+          });
+        }
       } // to speed up updates we keep track of branches which have a component with vue-meta info defined
       // if _vueMeta = true it has info, if _vueMeta = false a child has info
 
@@ -330,14 +402,18 @@ function createMixin(Vue, options) {
         $root[rootConfigKey].initialized = this.$isServer;
 
         if (!$root[rootConfigKey].initialized) {
-          ensuredPush($options, 'beforeMount', function () {
+          if (!$root[rootConfigKey].initializedSsr) {
-            var $root = this[rootKey]; // if this Vue-app was server rendered, set the appId to 'ssr'
+            $root[rootConfigKey].initializedSsr = true;
-            // only one SSR app per page is supported
+            ensuredPush($options, 'beforeMount', function () {
+              var $root = this; // if this Vue-app was server rendered, set the appId to 'ssr'
+              // only one SSR app per page is supported
+
+              if ($root.$el && $root.$el.nodeType === 1 && $root.$el.hasAttribute('data-server-rendered')) {
+                $root[rootConfigKey].appId = options.ssrAppId;
+              }
+            });
+          } // we use the mounted hook here as on page load
 
-            if ($root.$el && $root.$el.nodeType === 1 && $root.$el.hasAttribute('data-server-rendered')) {
-              $root[rootConfigKey].appId = options.ssrAppId;
-            }
-          }); // we use the mounted hook here as on page load
 
           ensuredPush($options, 'mounted', function () {
             var $root = this[rootKey];
@@ -383,6 +459,7 @@ function createMixin(Vue, options) {
 
 
       if (this.$isServer) {
+        /* istanbul ignore next */
         return;
       } // no need to add this hooks on server side
 
@@ -405,6 +482,7 @@ function createMixin(Vue, options) {
         return;
       }
 
+      delete this._hasMetaInfo;
       this.$nextTick(function () {
         if (!options.waitOnDestroyed || !_this.$el || !_this.$el.offsetParent) {
           triggerUpdate(options, _this.$root, 'destroyed');
@@ -459,49 +537,6 @@ function getOptions(options) {
   return optionsCopy;
 }
 
-/*
- * To reduce build size, this file provides simple polyfills without
- * overly excessive type checking and without modifying
- * the global Array.prototype
- * The polyfills are automatically removed in the commonjs build
- * Also, only files in client/ & shared/ should use these functions
- * files in server/ still use normal js function
- */
-function findIndex(array, predicate, thisArg) {
-  if ( !Array.prototype.findIndex) {
-    // idx needs to be a Number, for..in returns string
-    for (var idx = 0; idx < array.length; idx++) {
-      if (predicate.call(thisArg, array[idx], idx, array)) {
-        return idx;
-      }
-    }
-
-    return -1;
-  }
-
-  return array.findIndex(predicate, thisArg);
-}
-function toArray(arg) {
-  if ( !Array.from) {
-    return Array.prototype.slice.call(arg);
-  }
-
-  return Array.from(arg);
-}
-function includes(array, value) {
-  if ( !Array.prototype.includes) {
-    for (var idx in array) {
-      if (array[idx] === value) {
-        return true;
-      }
-    }
-
-    return false;
-  }
-
-  return array.includes(value);
-}
-
 var clientSequences = [[/&/g, "&"], [/</g, "<"], [/>/g, ">"], [/"/g, "\""], [/'/g, "'"]]; // sanitizes potentially dangerous characters
 
 function escape(info, options, escapeOptions, escapeKeys) {
@@ -776,14 +811,13 @@ function getComponentOption(options, component, result) {
     // and set to the computed prop $metaInfo in the mixin
     // using the computed prop should be a small performance increase
     // because Vue caches those internally
-    var data = $metaInfo || $options[keyName]; // ignore data if its not an object, then we keep our previous result
+    var data = $metaInfo || $options[keyName]; // only merge data with result when its an object
+    // eg it could be a function when metaInfo() returns undefined
+    // dueo to the or statement above
 
-    if (!isObject(data)) {
+    if (isObject(data)) {
-      return result;
+      result = merge(result, data, options);
-    } // merge with existing options
+    }
-
-
-    result = merge(result, data, options);
   } // collect & aggregate child options if deep = true
 
 
@@ -1501,7 +1535,7 @@ function install(Vue, options) {
 var index = {
   version: version,
   install: install,
-  generate: function generate(metaInfo) {
+  generate: function generate(metaInfo, options) {
     return  showWarningNotSupportedInBrowserBundle('generate');
   },
   hasMetaInfo: hasMetaInfo

dist/vue-meta.esm.js

@@ -1,5 +1,5 @@
 /**
- * vue-meta v2.3.0
+ * vue-meta v2.3.1
  * (c) 2019
  * - Declan de Wet
  * - Sébastien Chopin (@Atinux)
@@ -10,7 +10,7 @@
 
 import deepmerge from 'deepmerge';
 
-var version = "2.3.0";
+var version = "2.3.1";
 
 function _typeof(obj) {
   if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") {
@@ -229,6 +229,63 @@ function batchUpdate(callback, timeout) {
   return batchId;
 }
 
+/*
+ * To reduce build size, this file provides simple polyfills without
+ * overly excessive type checking and without modifying
+ * the global Array.prototype
+ * The polyfills are automatically removed in the commonjs build
+ * Also, only files in client/ & shared/ should use these functions
+ * files in server/ still use normal js function
+ */
+function find(array, predicate, thisArg) {
+  if ( !Array.prototype.find) {
+    // idx needs to be a Number, for..in returns string
+    for (var idx = 0; idx < array.length; idx++) {
+      if (predicate.call(thisArg, array[idx], idx, array)) {
+        return array[idx];
+      }
+    }
+
+    return;
+  }
+
+  return array.find(predicate, thisArg);
+}
+function findIndex(array, predicate, thisArg) {
+  if ( !Array.prototype.findIndex) {
+    // idx needs to be a Number, for..in returns string
+    for (var idx = 0; idx < array.length; idx++) {
+      if (predicate.call(thisArg, array[idx], idx, array)) {
+        return idx;
+      }
+    }
+
+    return -1;
+  }
+
+  return array.findIndex(predicate, thisArg);
+}
+function toArray(arg) {
+  if ( !Array.from) {
+    return Array.prototype.slice.call(arg);
+  }
+
+  return Array.from(arg);
+}
+function includes(array, value) {
+  if ( !Array.prototype.includes) {
+    for (var idx in array) {
+      if (array[idx] === value) {
+        return true;
+      }
+    }
+
+    return false;
+  }
+
+  return array.includes(value);
+}
+
 function ensureIsArray(arg, key) {
   if (!key || !isObject(arg)) {
     return isArray(arg) ? arg : [];
@@ -302,11 +359,12 @@ function createMixin(Vue, options) {
       var rootKey = '$root';
       var $root = this[rootKey];
       var $options = this.$options;
+      var devtoolsEnabled = Vue.config.devtools;
       Object.defineProperty(this, '_hasMetaInfo', {
         configurable: true,
         get: function get() {
           // Show deprecation warning once when devtools enabled
-          if (Vue.config.devtools && !$root[rootConfigKey].deprecationWarningShown) {
+          if (devtoolsEnabled && !$root[rootConfigKey].deprecationWarningShown) {
             warn('VueMeta DeprecationWarning: _hasMetaInfo has been deprecated and will be removed in a future version. Please use hasMetaInfo(vm) instead');
             $root[rootConfigKey].deprecationWarningShown = true;
           }
@@ -326,6 +384,20 @@ function createMixin(Vue, options) {
           appId: appId
         };
         appId++;
+
+        if (devtoolsEnabled && $root.$options[options.keyName]) {
+          // use nextTick so the children should be added to $root
+          this.$nextTick(function () {
+            // find the first child that lists fnOptions
+            var child = find($root.$children, function (c) {
+              return c.$vnode && c.$vnode.fnOptions;
+            });
+
+            if (child && child.$vnode.fnOptions[options.keyName]) {
+              warn("VueMeta has detected a possible global mixin which adds a ".concat(options.keyName, " property to all Vue components on the page. This could cause severe performance issues. If possible, use $meta().addApp to add meta information instead"));
+            }
+          });
+        }
       } // to speed up updates we keep track of branches which have a component with vue-meta info defined
       // if _vueMeta = true it has info, if _vueMeta = false a child has info
 
@@ -369,14 +441,18 @@ function createMixin(Vue, options) {
         $root[rootConfigKey].initialized = this.$isServer;
 
         if (!$root[rootConfigKey].initialized) {
-          ensuredPush($options, 'beforeMount', function () {
+          if (!$root[rootConfigKey].initializedSsr) {
-            var $root = this[rootKey]; // if this Vue-app was server rendered, set the appId to 'ssr'
+            $root[rootConfigKey].initializedSsr = true;
-            // only one SSR app per page is supported
+            ensuredPush($options, 'beforeMount', function () {
+              var $root = this; // if this Vue-app was server rendered, set the appId to 'ssr'
+              // only one SSR app per page is supported
+
+              if ($root.$el && $root.$el.nodeType === 1 && $root.$el.hasAttribute('data-server-rendered')) {
+                $root[rootConfigKey].appId = options.ssrAppId;
+              }
+            });
+          } // we use the mounted hook here as on page load
 
-            if ($root.$el && $root.$el.nodeType === 1 && $root.$el.hasAttribute('data-server-rendered')) {
-              $root[rootConfigKey].appId = options.ssrAppId;
-            }
-          }); // we use the mounted hook here as on page load
 
           ensuredPush($options, 'mounted', function () {
             var $root = this[rootKey];
@@ -422,6 +498,7 @@ function createMixin(Vue, options) {
 
 
       if (this.$isServer) {
+        /* istanbul ignore next */
         return;
       } // no need to add this hooks on server side
 
@@ -444,6 +521,7 @@ function createMixin(Vue, options) {
         return;
       }
 
+      delete this._hasMetaInfo;
       this.$nextTick(function () {
         if (!options.waitOnDestroyed || !_this.$el || !_this.$el.offsetParent) {
           triggerUpdate(options, _this.$root, 'destroyed');
@@ -498,49 +576,6 @@ function getOptions(options) {
   return optionsCopy;
 }
 
-/*
- * To reduce build size, this file provides simple polyfills without
- * overly excessive type checking and without modifying
- * the global Array.prototype
- * The polyfills are automatically removed in the commonjs build
- * Also, only files in client/ & shared/ should use these functions
- * files in server/ still use normal js function
- */
-function findIndex(array, predicate, thisArg) {
-  if ( !Array.prototype.findIndex) {
-    // idx needs to be a Number, for..in returns string
-    for (var idx = 0; idx < array.length; idx++) {
-      if (predicate.call(thisArg, array[idx], idx, array)) {
-        return idx;
-      }
-    }
-
-    return -1;
-  }
-
-  return array.findIndex(predicate, thisArg);
-}
-function toArray(arg) {
-  if ( !Array.from) {
-    return Array.prototype.slice.call(arg);
-  }
-
-  return Array.from(arg);
-}
-function includes(array, value) {
-  if ( !Array.prototype.includes) {
-    for (var idx in array) {
-      if (array[idx] === value) {
-        return true;
-      }
-    }
-
-    return false;
-  }
-
-  return array.includes(value);
-}
-
 var serverSequences = [[/&/g, '&amp;'], [/</g, '&lt;'], [/>/g, '&gt;'], [/"/g, '&quot;'], [/'/g, '&#x27;']];
 var clientSequences = [[/&/g, "&"], [/</g, "<"], [/>/g, ">"], [/"/g, "\""], [/'/g, "'"]]; // sanitizes potentially dangerous characters
 
@@ -816,14 +851,13 @@ function getComponentOption(options, component, result) {
     // and set to the computed prop $metaInfo in the mixin
     // using the computed prop should be a small performance increase
     // because Vue caches those internally
-    var data = $metaInfo || $options[keyName]; // ignore data if its not an object, then we keep our previous result
+    var data = $metaInfo || $options[keyName]; // only merge data with result when its an object
+    // eg it could be a function when metaInfo() returns undefined
+    // dueo to the or statement above
 
-    if (!isObject(data)) {
+    if (isObject(data)) {
-      return result;
+      result = merge(result, data, options);
-    } // merge with existing options
+    }
-
-
-    result = merge(result, data, options);
   } // collect & aggregate child options if deep = true
 
 
@@ -1815,8 +1849,8 @@ function install(Vue, options) {
 var index = {
   version: version,
   install: install,
-  generate: function generate$1(metaInfo) {
+  generate: function generate$1(metaInfo, options) {
-    return  generate(metaInfo) ;
+    return  generate(metaInfo, options) ;
   },
   hasMetaInfo: hasMetaInfo
 };

dist/vue-meta.js

@@ -1,5 +1,5 @@
 /**
- * vue-meta v2.3.0
+ * vue-meta v2.3.1
  * (c) 2019
  * - Declan de Wet
  * - Sébastien Chopin (@Atinux)
@@ -14,7 +14,7 @@
   (global = global || self, global.VueMeta = factory());
 }(this, function () { 'use strict';
 
-  var version = "2.3.0";
+  var version = "2.3.1";
 
   function _typeof(obj) {
     if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") {
@@ -194,6 +194,63 @@
     return batchId;
   }
 
+  /*
+   * To reduce build size, this file provides simple polyfills without
+   * overly excessive type checking and without modifying
+   * the global Array.prototype
+   * The polyfills are automatically removed in the commonjs build
+   * Also, only files in client/ & shared/ should use these functions
+   * files in server/ still use normal js function
+   */
+  function find(array, predicate, thisArg) {
+    if ( !Array.prototype.find) {
+      // idx needs to be a Number, for..in returns string
+      for (var idx = 0; idx < array.length; idx++) {
+        if (predicate.call(thisArg, array[idx], idx, array)) {
+          return array[idx];
+        }
+      }
+
+      return;
+    }
+
+    return array.find(predicate, thisArg);
+  }
+  function findIndex(array, predicate, thisArg) {
+    if ( !Array.prototype.findIndex) {
+      // idx needs to be a Number, for..in returns string
+      for (var idx = 0; idx < array.length; idx++) {
+        if (predicate.call(thisArg, array[idx], idx, array)) {
+          return idx;
+        }
+      }
+
+      return -1;
+    }
+
+    return array.findIndex(predicate, thisArg);
+  }
+  function toArray(arg) {
+    if ( !Array.from) {
+      return Array.prototype.slice.call(arg);
+    }
+
+    return Array.from(arg);
+  }
+  function includes(array, value) {
+    if ( !Array.prototype.includes) {
+      for (var idx in array) {
+        if (array[idx] === value) {
+          return true;
+        }
+      }
+
+      return false;
+    }
+
+    return array.includes(value);
+  }
+
   function ensureIsArray(arg, key) {
     if (!key || !isObject(arg)) {
       return isArray(arg) ? arg : [];
@@ -267,11 +324,12 @@
         var rootKey = '$root';
         var $root = this[rootKey];
         var $options = this.$options;
+        var devtoolsEnabled = Vue.config.devtools;
         Object.defineProperty(this, '_hasMetaInfo', {
           configurable: true,
           get: function get() {
             // Show deprecation warning once when devtools enabled
-            if (Vue.config.devtools && !$root[rootConfigKey].deprecationWarningShown) {
+            if (devtoolsEnabled && !$root[rootConfigKey].deprecationWarningShown) {
               warn('VueMeta DeprecationWarning: _hasMetaInfo has been deprecated and will be removed in a future version. Please use hasMetaInfo(vm) instead');
               $root[rootConfigKey].deprecationWarningShown = true;
             }
@@ -291,6 +349,20 @@
             appId: appId
           };
           appId++;
+
+          if (devtoolsEnabled && $root.$options[options.keyName]) {
+            // use nextTick so the children should be added to $root
+            this.$nextTick(function () {
+              // find the first child that lists fnOptions
+              var child = find($root.$children, function (c) {
+                return c.$vnode && c.$vnode.fnOptions;
+              });
+
+              if (child && child.$vnode.fnOptions[options.keyName]) {
+                warn("VueMeta has detected a possible global mixin which adds a ".concat(options.keyName, " property to all Vue components on the page. This could cause severe performance issues. If possible, use $meta().addApp to add meta information instead"));
+              }
+            });
+          }
         } // to speed up updates we keep track of branches which have a component with vue-meta info defined
         // if _vueMeta = true it has info, if _vueMeta = false a child has info
 
@@ -334,14 +406,18 @@
           $root[rootConfigKey].initialized = this.$isServer;
 
           if (!$root[rootConfigKey].initialized) {
-            ensuredPush($options, 'beforeMount', function () {
+            if (!$root[rootConfigKey].initializedSsr) {
-              var $root = this[rootKey]; // if this Vue-app was server rendered, set the appId to 'ssr'
+              $root[rootConfigKey].initializedSsr = true;
-              // only one SSR app per page is supported
+              ensuredPush($options, 'beforeMount', function () {
+                var $root = this; // if this Vue-app was server rendered, set the appId to 'ssr'
+                // only one SSR app per page is supported
+
+                if ($root.$el && $root.$el.nodeType === 1 && $root.$el.hasAttribute('data-server-rendered')) {
+                  $root[rootConfigKey].appId = options.ssrAppId;
+                }
+              });
+            } // we use the mounted hook here as on page load
 
-              if ($root.$el && $root.$el.nodeType === 1 && $root.$el.hasAttribute('data-server-rendered')) {
-                $root[rootConfigKey].appId = options.ssrAppId;
-              }
-            }); // we use the mounted hook here as on page load
 
             ensuredPush($options, 'mounted', function () {
               var $root = this[rootKey];
@@ -387,6 +463,7 @@
 
 
         if (this.$isServer) {
+          /* istanbul ignore next */
           return;
         } // no need to add this hooks on server side
 
@@ -409,6 +486,7 @@
           return;
         }
 
+        delete this._hasMetaInfo;
         this.$nextTick(function () {
           if (!options.waitOnDestroyed || !_this.$el || !_this.$el.offsetParent) {
             triggerUpdate(options, _this.$root, 'destroyed');
@@ -463,49 +541,6 @@
     return optionsCopy;
   }
 
-  /*
-   * To reduce build size, this file provides simple polyfills without
-   * overly excessive type checking and without modifying
-   * the global Array.prototype
-   * The polyfills are automatically removed in the commonjs build
-   * Also, only files in client/ & shared/ should use these functions
-   * files in server/ still use normal js function
-   */
-  function findIndex(array, predicate, thisArg) {
-    if ( !Array.prototype.findIndex) {
-      // idx needs to be a Number, for..in returns string
-      for (var idx = 0; idx < array.length; idx++) {
-        if (predicate.call(thisArg, array[idx], idx, array)) {
-          return idx;
-        }
-      }
-
-      return -1;
-    }
-
-    return array.findIndex(predicate, thisArg);
-  }
-  function toArray(arg) {
-    if ( !Array.from) {
-      return Array.prototype.slice.call(arg);
-    }
-
-    return Array.from(arg);
-  }
-  function includes(array, value) {
-    if ( !Array.prototype.includes) {
-      for (var idx in array) {
-        if (array[idx] === value) {
-          return true;
-        }
-      }
-
-      return false;
-    }
-
-    return array.includes(value);
-  }
-
   var clientSequences = [[/&/g, "&"], [/</g, "<"], [/>/g, ">"], [/"/g, "\""], [/'/g, "'"]]; // sanitizes potentially dangerous characters
 
   function escape(info, options, escapeOptions, escapeKeys) {
@@ -848,14 +883,13 @@
       // and set to the computed prop $metaInfo in the mixin
       // using the computed prop should be a small performance increase
       // because Vue caches those internally
-      var data = $metaInfo || $options[keyName]; // ignore data if its not an object, then we keep our previous result
+      var data = $metaInfo || $options[keyName]; // only merge data with result when its an object
+      // eg it could be a function when metaInfo() returns undefined
+      // dueo to the or statement above
 
-      if (!isObject(data)) {
+      if (isObject(data)) {
-        return result;
+        result = merge(result, data, options);
-      } // merge with existing options
+      }
-
-
-      result = merge(result, data, options);
     } // collect & aggregate child options if deep = true
 
 
@@ -1573,7 +1607,7 @@
   var index = {
     version: version,
     install: install,
-    generate: function generate(metaInfo) {
+    generate: function generate(metaInfo, options) {
       return  showWarningNotSupportedInBrowserBundle('generate');
     },
     hasMetaInfo: hasMetaInfo

package.json

@@ -1,6 +1,6 @@
 {
   "name": "vue-meta",
-  "version": "2.3.0",
+  "version": "2.3.1",
   "description": "Manage HTML metadata in Vue.js components with ssr support",
   "keywords": [
     "attribute",