Function validator

packages-private/dts-test/defineComponent.test-d.tsx:352–355

(val: unknown)

      myProp: {
        type: Number,
        validator(val: unknown): boolean {
          // @ts-expect-error
          return val !== this.otherProp
        },
        default(): number {
          // @ts-expect-error
          return this.otherProp + 1