Ability to override default isComponentOfType implementation (#1164)

components/index.js

@@ -1,4 +1,5 @@
 import './utils/polyfills'; // Import polyfills for IE11
+export { overrideComponentTypeChecker } from './utils/is-component-of-type';
 export AppBar from './app_bar';
 export Autocomplete from './autocomplete';
 export Avatar from './avatar';

components/utils/is-component-of-type.js

@@ -1,9 +1,33 @@
+let customChecker;
+
+/**
+ *  Sets customChecker which will be used for all components.
+ *
+ * @param providedChecker {Function} - Checker function
+ */
+export function overrideComponentTypeChecker (providedChecker) {
+  customChecker = providedChecker;
+}
+
 /**
  * Returns true if the provided element is a component of the provided type.
  *
  * @param classType {ReactElement class} - the class of a React Element
  * @param reactElement {ReactElement} - any React Element (not a real DOM node)
  */
-export default function isComponentOfType (classType, reactElement) {
+export function defaultChecker (classType, reactElement) {
   return reactElement && reactElement.type === classType;
 }
+
+
+/**
+ * Executes customChecker if it's set or defaultChecker.
+ *
+ * @param classType {ReactElement class} - the class of a React Element
+ * @param reactElement {ReactElement} - any React Element (not a real DOM node)
+ */
+export default function isComponentOfType (classType, reactElement) {
+  return customChecker
+    ? customChecker(classType, reactElement)
+    : defaultChecker(classType, reactElement);
+}