Uncaught SyntaxError: Unexpected token u in JSON at position 0

Question

Only at the checkout and on individual product pages I am getting the following error in the console log:

VM35594:1 Uncaught SyntaxError: Unexpected token u          


        

Answer 1

As @Seth Holladay @MinusFour commented, you are parsing an undefined variable.
Try adding an if condition before doing the parse.

if (typeof test1 !== 'undefined') { test2 = JSON.parse(test1); }

Note: This is just a check for undefined case. Any other parsing issues still need to be handled.