vue3+ts props

In Vue 3 with TypeScript, props can be defined in the following way:

import { defineComponent, PropType } from 'vue';

export default defineComponent({
  name: 'MyComponent',
  props: {
    propA: {
      type: String as PropType<string>,
      required: true,
      default: 'default value',
      validator: (value: string) => {
        // custom validation logic
        return value.length > 0;
      }
    },
    propB: {
      type: [String, Number] as PropType<string | number>,
      default: 100
    }
  }
});

In the example above, `propA` is a required string prop with a default value of `'default value'` and a custom validator function that checks if the value has a length greater than 0. `propB` is a prop that can be either a string or a number, with a default value of `100`.

Note that the `PropType` type is used to specify the type of the prop, and can accept a single type or an array of types. Also, the validator function should return `true` if the value is valid, and `false` otherwise.