Add tests and update readme

README.md

@@ -51,7 +51,7 @@ Possible values are.
 **Example**
 
 ```js
-import $iterator$, {getSymbolIterator(iterable)} from 'symbol-iterator-x';
+import $iterator$, {getSymbolIterator} from 'symbol-iterator-x';
 
 const array = [];
 

__tests__/symbol-iterator-x.test.js

@@ -1,10 +1,19 @@
-import symIt from '../src/symbol-iterator-x';
+import $iterator$, {getSymbolIterator} from '../src/symbol-iterator-x';
 
 describe('symbol iterator', function() {
   it('is a symbol or string', function() {
     expect.assertions(1);
-    const type = typeof symIt;
+    const type = typeof $iterator$;
     const isType = ['symbol', 'string'].some((val) => val === type);
     expect(isType).toBe(true);
   });
+
+  it('getSymbolIterator', function() {
+    expect.assertions(5);
+    expect(getSymbolIterator([])).toBe($iterator$);
+    expect(getSymbolIterator(undefined)).toBeUndefined();
+    expect(getSymbolIterator(null)).toBeUndefined();
+    expect(getSymbolIterator(1)).toBeUndefined();
+    expect(getSymbolIterator(true)).toBeUndefined();
+  });
 });

package.json

@@ -1,6 +1,6 @@
 {
   "name": "symbol-iterator-x",
-  "version": "1.0.1",
+  "version": "1.0.2",
   "description": "The system Symbol.iterator (real or fake)",
   "homepage": "https://github.com/Xotic750/symbol-iterator-x",
   "author": {