CraigCav

  var nameFormat = /^(\w+__)?([A-Za-z0-9]+(?:_?[A-Za-z0-9]+)+)*(__+.)?$/;
  
  var [match, namespace, name, suffix] = nameFormat.exec('NS1__Foo__c');
  
  console.log(namespace); // logs: "NS1__"
  console.log(name);      // logs: "Foo"
  console.log(suffix);    // logs: "__c"