[Feature] Hightlight warning if variables or methods returned but not using in template html

[natuan62]

Example

<template>
  <div v-if="var_1">

  </div>
  <div v-if="method_1()">

  </div>
</template>

setup() {
   return {
      var_1,
      var_2, // warning
      method_1,
      method_2, // warning
    };
}

[johnsoncodehk]

This was a feature we had in the past, since we have script setup now, we removed it due to maintenance costs, unfortunately there are no plans to add it back.

[KID-joker]

I think it's necessary when using Options API.