[+] Added isTag utils

[+] Added isStyledComponent utils
[+] Add isVueComponent utils
[+] Better isValidElementType check

Author: liqueflies

src/utils/isStyledComponent.js

@@ -0,0 +1,3 @@
+export default function isStyledComponent (target) {
+  return target && typeof target.generatedClassName === 'string'
+}

src/utils/isTag.js

@@ -0,0 +1,8 @@
+
+import domElements from './domElements'
+
+export default function isTag (target) {
+  if (typeof target === 'string') {
+    return domElements.indexOf(target) !== -1
+  }
+}

src/utils/isValidElementType.js

@@ -1,14 +1,9 @@
-import domElements from './domElements'
+import isTag from './isTag'
+import isVueComponent from './isVueComponent'
+import isStyledComponent from './isStyledComponent'
 
-export default function isValidElementType (tag) {
-  if (typeof tag === 'undefined' || typeof tag === 'number') {
-    return false
-  }
-  if (typeof tag === 'string') {
-    return domElements.indexOf(tag) !== -1
-  }
-  if (typeof tag === 'object') {
-    return !!tag.template || !!tag.withComponent || !!tag.functional
-  }
-  return true
+export default function isValidElementType (target) {
+  return isTag(target) ||
+    isVueComponent(target) ||
+    isStyledComponent(target)
 }

src/utils/isVueComponent.js

@@ -0,0 +1,3 @@
+export default function isVueComponent (target) {
+  return target && typeof target.render === 'function'
+}