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node.jsjsonresponseauthorize.net

NodeJS SyntaxError: Unexpected token in JSON at position 0

The body of the response from Authorize.net's sandbox API is:

{
  "messages": {
    "resultCode": "Error",
    "message": [
      {
        "code": "E00012",
        "text": "You have submitted a duplicate of Subscription 5777085. A duplicate subscription will not be created."
      }
    ]
  }
}

but when I go to parse it:

try {
   bodyObj = JSON.parse(body);
} catch (ex) {
   console.error(ex);
}

I get this error:

SyntaxError: Unexpected token in JSON at position 0

And this: console.log(response.headers['content-type']);

returns this: application/json; charset=utf-8

What am I doing wrong? I want to parse the JSON into a JS object.

Solution

  • Actually you didn't see it, but there was a invisible unicode character, specifically the byte order mark at the beginning of the JSON.
    Since the byte order mark is not a valid JSON character, JSON.parse rejected it.
    byte order mark image
    To remove, use the following code.

    function removeByteOrderMark(str){
    return str.replace(/^\ufeff/g,"")
}
// OR (faster),
let removeByteOrderMark = a=>a[0]=="\ufeff"?a.slice(1):a