The expression-related settings (defaultValueExpression, resetValueExpression, setValueExpression) are preserved when an Expression field is converted from another question

[JaneSjs]

T22023 - Possible bug in survey creator
https://surveyjs.answerdesk.io/internal/ticket/details/T22023

---

Consider the following survey JSON:

{
  "pages": [
    {
      "name": "page1",
      "title": "Page 1",
      "elements": [
        {
          "type": "boolean",
          "name": "copyValue",
          "title": "Copy value"
        },
        {
          "type": "text",
          "name": "sourceQuestion",
          "title": "Source Question",
          "defaultValue": "Source Value"
        },
        {
          "type": "text",
          "name": "targetQuestion",
          "title": "Target Question",
          "resetValueIf": "{copyValue} = false",
          "setValueIf": "{copyValue} = true",
          "setValueExpression": "{sourceQuestion}",
          "defaultValueExpression": "today()"
        }
      ]
    }
  ]
}

The targetQuestion contains various expression-related settings. If you convert this question to Expression, these settings are preserved:

{
          "type": "expression",
          "name": "targetQuestion",
          "title": "Target Question",
          "resetValueIf": "{copyValue} = false",
          "setValueIf": "{copyValue} = true",
          "setValueExpression": "{sourceQuestion}",
          "defaultValueExpression": "today()"
}

The full survey JSON:

{
  "pages": [
    {
      "name": "page1",
      "title": "Page 1",
      "elements": [
        {
          "type": "boolean",
          "name": "copyValue",
          "title": "Copy value"
        },
        {
          "type": "text",
          "name": "sourceQuestion",
          "title": "Source Question",
          "defaultValue": "Source Value"
        },
        {
          "type": "expression",
          "name": "targetQuestion",
          "title": "Target Question",
          "resetValueIf": "{copyValue} = false",
          "setValueIf": "{copyValue} = true",
          "setValueExpression": "{sourceQuestion}",
          "defaultValueExpression": "today()"
        }
      ]
    }
  ]
}

However, the Expression field expects that it's expression is defined rather than those expression settings. If you define the expression property value, those expression-related settings have no effect.

{
          "type": "expression",
          "name": "targetQuestion",
          "title": "Target Question",
          "resetValueIf": "{copyValue} = false",
          "setValueIf": "{copyValue} = true",
          "setValueExpression": "{sourceQuestion}",
          "defaultValueExpression": "today()",
          "expression": "{sourceQuestion}"
}

A full JSON:

{
  "pages": [
    {
      "name": "page1",
      "title": "Page 1",
      "elements": [
        {
          "type": "boolean",
          "name": "copyValue",
          "title": "Copy value"
        },
        {
          "type": "text",
          "name": "sourceQuestion",
          "title": "Source Question",
          "defaultValue": "Source Value"
        },
        {
          "type": "expression",
          "name": "targetQuestion",
          "title": "Target Question",
          "resetValueIf": "{copyValue} = false",
          "setValueIf": "{copyValue} = true",
          "setValueExpression": "{sourceQuestion}",
          "defaultValueExpression": "today()",
          "expression": "{sourceQuestion}"
        }
      ]
    }
  ]
}

In the original ticket, a user expects that defaultValueExpression is reset when an Expression field is being converted from another question type.