He swears that I prop mutate, why?

Question

typescript

I don't change the prop href, but the console says "Avoid mutating a prop directly since the value will be overwritten whenever the parent component re-renders." Why? Through getter/computed does not help at all. Everything works, but a warning spits into the console.

<template>
  <div>
    <a :href="href" target="_blank">
      <slot>[Default slot]</slot>
    </a>
    <slot name="named-1">[Default named slot 1]</slot>
    <slot name="named-2">[Default named slot 2]</slot>
  </div>
</template>

<script lang="ts">
import Vue from 'vue';
import { Component, Prop } from 'vue-property-decorator';

@Component
export default class SlotsComponent extends Vue {
  @Prop(String)
  href = '';
}
</script>

Answer 1

I don't change the prop href

What about trying to set a default value? Maybe it is considered as a parameter mutation:

@Prop(String)
href = '';

Attempt, by the way, a curve :

It's not supported to define each defaultproperty like @Prop() prop = 'default value'.