increate test coverage rate

Author: lcxfs1991

.gitignore

@@ -6,3 +6,5 @@
 /coverage
 
 /.idea
+
+.DS_Store

index.js

@@ -152,10 +152,6 @@ function isString(a) {
 	return typeof a === "string";
 }
 
-function isObject(a) {
-	return isType('Object', a);
-}
-
 function isFunction(a) {
 	return isType('Function', a);
 }