Merge pull request #7 from functionalland/feature/types

Fix bug with components that don't have an initial callback function

Author: sebastienfilion

library/component.ts

@@ -792,7 +792,7 @@ export const useTemplate = <
           configurable: true,
           enumerable: true,
           value(this: E) {
-            return maybeCall(() => _connectedCallback.call(this))
+            return maybeCall(() => _connectedCallback && _connectedCallback.call(this))
               .then(() => maybeCall<HTMLTemplateElement>(f))
               .then((template) => {
                 if (!template) return;