Implement NodeTransform that transforms child props based on parent props?

[ozzyfromspace]

Context: The deeper goal is to perform an AST transformation on a child node's props using information from a parent node's props. I'm genuinely stuck.

Lets assume I have the following:

<script lang="ts" setup>
import { ref } from 'vue'

const startingValue = ref('option_b')
</script>

<template>
  <select :default-value="startingValue">
    <option value="option_a">
      Option A
    </option>
    <option value="option_b">
      Option B
    </option>
  </select>
</template>

My goal in this example is to perform a node transformation on the <option /> props by identifying which option should be selected based on defaultValue and value. After the AST transform, we should get a template with a selected attribute, like so:

<script lang="ts" setup>
import { ref } from 'vue'

const startingValue = ref('option_b')
</script>

<template>
  <select :default-value="startingValue">
    <option value="option_a">
      Option A
    </option>
    <option
      value="option_b"
      selected="true"
    >
      Option B
    </option>
  </select>
</template>

My approach has been to define a NodeTransformation function that grabs the SimpleExpressionNode and compares it to some other expression. However, I get:

[Vue warn]: Property "$setup" was accessed during render but is not defined on instance.

I believe this is happening because the context that contains the variables in the SFC's setup tags are unavailable to <option />, but I could be wrong. Could someone more knowledgeable please help me understand how I can actually implement an AST that assigns the correct selected attribute to the <option /> tag?

Please let me know if I can supply anything else that makes it easier for you to provide guidance. Many thanks in advance!

Disclaimer: I am aware that this is a solved problem through v-model. This question exists because I have other considerations that disqualify v-model.