Expressions: The `contains` operator ignores the case sensitivity setting

[JaneSjs]

T26065 - Is there any built-in-function available in a Survey JS to make the question value as lowercase or uppercase?
https://surveyjs.answerdesk.io/internal/ticket/details/T26065

The = operator is case-insensitive by default and can be made case-sensitive by enabling the settings.comparator.caseSensitive option. However, the contains operator is always case-sensitive.

@andrewtelnov Could you please clarify whether the contains operator is intentionally case-sensitive by default because it is typically used for substring matching and is expected to be strict, as lowercasing everything might hide real differences or create unexpected matches?

Example 1: Use =

{
  "pages": [
    {
      "name": "page1",
      "elements": [
        {
          "type": "text",
          "name": "question1"
        },
        {
          "type": "text",
          "name": "question2",
          "visibleIf": "{question1} = 'TEST'"
        }
      ]
    }
  ]
}

Example 2: Use contains

{
  "pages": [
    {
      "name": "page1",
      "elements": [
        {
          "type": "text",
          "name": "question1"
        },
        {
          "type": "text",
          "name": "question2",
          "visibleIf": "{question1} contains 'TEST'"
        }
      ]
    }
  ]
}