scripts validation endpoint returns valid even for invalid scripts

When using action_validate, true is returned even when the script is not a valid script.

Steps to reproduce:
1) Login as amadmin
2) Navigate to API descriptor -> scripts (openam/XUI/#api/explorer/scripts)
3) Select "/scripts#1.1_action_validate"
4) Use valid payload like:

{
  "script": "dmFyIGkgPSAxOw==",
  "language": "JAVASCRIPT"
}

Note: script is base64 encoded source code in this case

var i = 1;

5) Click "Try it out!"
6) Observe successful validation
7) Next use invalid payload like (script contains word "text" which is not valid Javascript):

{
  "script": "dGVzdA==",
  "language": "JAVASCRIPT"
}

Expected result:
Validation fails

Actual result:
Validation is successful.