valuesMethodsSetupComponent.vue

// ...
<script>
import { value } from 'vue-function-api'

const TestComponent = {
  props: {
    name: String
  },
  setup(props) {
    const message = value('Hello guest!')
    const getName = () => {
      message.value = `Hello ${props.name}!`
    }
    
    return {
      message,
      getName
    }
  },
  template: `<div @click="getName">{{ message }}</div>`
}
</script>
// ...