Vue.js: How to use TypeScript with Vue 3?

1npm install -D typescript vue-tsc

1<script setup lang="ts">
2import { ref, computed } from "vue"
3
4interface User {
5    id: number
6    name: string
7}
8
9const user = ref<User | null>(null)
10const displayName = computed(() => user.value?.name ?? "Guest")
11</script>

1<script setup lang="ts">
2const props = defineProps<{
3    title: string
4    count?: number
5}>()
6</script>