How to add check of any number of Blank space in apigee javascript

[IamSanketMore]

Seems trim(), replace(), match and regex.test() are not accessiable in apigee 
so how we add check for blank spaces , i had one method its check for empty field with "" but i need for "  " , "     " .etc  this kind of dyanamically spaces check 

function checkEmpty(value) {
if (value === "" || value === null || value === undefined) {
return false;
} else
return true;
}
this is working for me , just wanted check for dyanamic number of blank space

[pablosan · Accepted solution]

The below sample code works in both Apigee X/Edge - Rhino 1.7.13 and Rhino 1.7.12 respectively. Note that I tried both .match and .test and both works fine. 

function isEmptyOrSpaces(str){
  //return str === null || str.match(/^\s*$/) !== null;
  return str === null || (/^\s*$/).test(str);
}

var stringWithSpaces = '   ';

if(isEmptyOrSpaces(stringWithSpaces)){
    print("String has spaces");
}