Attribute option value uniqueness is not checked if created via REST Api

[hilrob]

Preconditions

1. Magento CE 2.1.4
2. PHP 7.x
3. MySQL 5.7

Steps to reproduce

1. Send the same call to create an option twice
   URL: /rest/V1/products/attributes/color/options
   POST:

{
    "option": {
      "label": "Black1",
      "sort_order": 9999,
      "is_default": false
    }
}

2. Get the attribute via API or check the backend
   Response:

[
  {
    "label": "offwhite/schwarz gestreift",
    "value": "281"
  },
  {
    "label": "red1",
    "value": "286"
  },
  {
    "label": "schwarz/mehrfarbig",
    "value": "282"
  },
  {
    "label": "Black1",
    "value": "287"
  },
  {
    "label": "Black1",
    "value": "288"
  },
  {
    "label": "Black1",
    "value": "289"
  }
]

Expected result

1. Only one option value is created
2. Second call must fail with exception

Actual result

1. Option values are created more than once.

[VasylShvorak]

@hilrob Thanks for reporting this issue. Created internal issue MAGETWO-70441 to investigate and track this issue.

[magento-engcom-team]

@hilrob, thank you for your report.
We've created internal ticket(s) MAGETWO-70441 to track progress on the issue.

[gomencal]

Working on that :)

[okorshenko]

Hi @gomencal please, accept the invite

[gomencal]

Hi! Accepted :)

[magento-team]

Hi @hilrob. Thank you for your report.
The issue has been fixed in magento-engcom/magento2ce#1286 by @magento-engcom-team in 2.3-develop branch
Related commit(s):

The fix will be available with the upcoming patch release.

[robsoned]

Hi! I can see here that it is fixed at 2.3.x. But should it duplicate as well if I make a PUT request to

V1/products/attributes/{attribute_code}

Where I have the options listened on the request. For example, if I have an attribute with an option that has the label "Option Label" and makes the put request with the following options inside the attribute Json request:

{ "options": [ { "label": "Option Label" } ] }

I get these options inside the attribute.

"options": [ { "label": " ", "value": "" }, { "label": "Option Label", "value": "82" }, { "label": "Option Label", "value": "83" } ],

With the duplicated label.
Is it the right behave?
Should I forget updating the options on the attribute request and instead do it on

/rest/V1/products/attributes/{attribute_code}/options

Thanks a lot!

[oefterdal]

We experience this bug with version 2.3.5-p1