I have a component which receives 3 arrays as props, and I want to concatenate them all together before rendering. But I keep getting these TypeScript errors:

<script lang="ts">
import {RisikoentitetRevision, IdentitetsmarkoerRevision, RisikomarkeringRevision} from '@/model/Risikoentitet'
import {defineComponent, computed, PropType} from 'vue'

export default defineComponent({
  name: 'HistorikLogTabel',
  props: {
    risikoentitetRevisioner: {
      type: Array as PropType<RisikoentitetRevision[]>,
      required: true,
    },
    identitetsmarkoerRevisioner: {
      type: Array as PropType<IdentitetsmarkoerRevision[][]>,
      required: true,
    },
    risikomarkeringRevisioner: {
      type: Array as PropType<RisikomarkeringRevision[][]>,
      required: true,
    },
  },
  setup(props) {
    console.log({props})
    const allRevisions = computed(() => {
      console.log("2nd", {props})
      return [
        ...props.risikoentitetRevisioner, // TODO: TS2488: Type 'unknown' must have a '[Symbol.iterator]()' method that returns an iterator.
        ...props.identitetsmarkoerRevisioner.flat(), // TODO: TS2339: Property 'flat' does not exist on type 'unknown'.
        ...props.risikomarkeringRevisioner.flat(), // TODO: TS2339: Property 'flat' does not exist on type 'unknown'.
      ]
    })
    return {
      allRevisions,
    }
  }
})
</script>

I’m not quite sure what I’m doing wrong. I have tried passing props into the argument in computed but it made no difference.

EDIT:

There is a workaround to ignore the TS errors, and the logic still works as expected. But it is not optimal and I would really like to find out what the TS problem is.

    const allRevisions = computed(() => {
      console.log("2nd", {props})
      return [
        // @ts-ignore
        ...props.risikoentitetRevisioner, // TODO: TS2488: Type 'unknown' must have a '[Symbol.iterator]()' method that returns an iterator.
        // @ts-ignore
        ...props.identitetsmarkoerRevisioner.flat(), // TODO: TS2339: Property 'flat' does not exist on type 'unknown'.
        // @ts-ignore
        ...props.risikomarkeringRevisioner.flat(), // TODO: TS2339: Property 'flat' does not exist on type 'unknown'.
      ]
    })
    console.log({allRevisions})