generics.ts

type Booking = {
  id: number,
  name: string
}

type BookingAndShit = {
  selected?:boolean
}




type TNode = {
  node: any
}

type TEdge = {    
  edges: TNode[]
}

       
interface INormalizeDataFromEdge<M> {
    source: TEdge
    metaData?: M
}


const data: TEdge = {
  edges: [
    {
      node: {
        id: 100
      },            
    },
    {
      node: {
        id: 101
      },            
    },

    {
      node: {
        id: 102
      },            
    }

  ]
}


function normalizeDataFromEdge<T,M = unknown | null>({source, metaData}: INormalizeDataFromEdge<M>):T[] {

  if (!source.edges) {
    return [] as T[]
  }

  const nodes =  source.edges.map(edge => {
    return { ...edge.node, ...metaData}
  })

  return nodes as T[]
}


console.log(normalizeDataFromEdge<Booking>(
  { 
    source: { edges:  [{node: {a:1}}]}
  }))

console.log(normalizeDataFromEdge<Booking,BookingAndShit>({ source: data, metaData: {selected: true}} ))