[рони]

WGN,

function fn(str)
  {  var reg = [/Ab1/, /^@[\w\.]+$/, /^(https?:\/\/)?instagram\.com\/\S+$/];
     str = str.trim().split(/\s+/);
     return str.length == 3 && str.every(function(s,i) {
     return reg[i].test(s)
     })
  }
 var str = 'Ab1 @any_text.text instagram.com/anylink';
 var ok = fn(str);
 alert(ok); //true
 str = 'Ab1 @any_text.text instagram.com/';
 ok = fn(str);
 alert(ok); //false
  str = 'Ab1 @sample3_text.text2. instagram.com/12345';
 ok = fn(str);
 alert(ok); //true