Typescriptでのリストの変更の書き方がわからない

実現したいこと

以下の「変更前データ」を「変更後のデータ」に変更する。

変更前データ

[
{
"id": "い",
"fruits": "apple",
"cd_1": [1,1],
"cd_2": ["あ","あ"]
},
{
"id": "い",
"fruits": "apple",
"cd_1": [2,3,4],
"cd_2": ["い","う","え"]
},
{
"id": "い",
"fruits": "apple",
"cd_1": [4,2],
"cd_2": ["え","い"]
},
{
"id": "ろ",
"fruits": "banana",
"cd_1": [5,6],
"cd_2": ["お","か"]
},
{
"id": "は",
"fruits": "grape",
"cd_1": [3],
"cd_2": ["う"]
},
{
"id": "は",
"fruits": "grape",
"cd_1": [6,9],
"cd_2": ["か","け"]
},
{
"id": "は",
"fruits": "grape",
"cd_1": [7,8],
"cd_2": ["き","く"]
},
]

変更後データ

{
  'い': [
    { id: 'い', fruits: 'apple', cd_1: [1,1], cd_2: ["あ","あ"] },
    { id: 'い', fruits: 'apple', cd_1: [2,3,4], cd_2: ["い","う","え"] },
    { id: 'い', fruits: 'apple', cd_1: [4,2], cd_2: ["え","い"] }
  ],
  'ろ': [ { id: 'ろ', fruits: 'banana', cd_1: [5,6], cd_2: ["お","か"] } ],
  'は': [
    { id: 'は', fruits: 'grape', cd_1:[3],  cd_2: ["う"] },
    { id: 'は', fruits: 'grape', cd_1: [6,9], cd_2: ["か","け"] },
    { id: 'は', fruits: 'grape', cd_1: [7,8], cd_2: ["き","く"] }
  ]
}

現在のソースコード

const data = [
{
"id": "い",
"fruits": "apple",
"cd_1": [1,1],
"cd_2": ["あ","あ"]
},
{
"id": "い",
"fruits": "apple",
"cd_1": [2,3,4],
"cd_2": ["い","う","え"]
},
{
"id": "い",
"fruits": "apple",
"cd_1": [4,2],
"cd_2": ["え","い"]
},
{
"id": "ろ",
"fruits": "banana",
"cd_1": [5,6],
"cd_2": ["お","か"]
},
{
"id": "は",
"fruits": "grape",
"cd_1": [3],
"cd_2": ["う"]
},
{
"id": "は",
"fruits": "grape",
"cd_1": [6,9],
"cd_2": ["か","け"]
},
{
"id": "は",
"fruits": "grape",
"cd_1": [7,8],
"cd_2": ["き","く"]
},
]


export interface Item {
  id: string;
  fruits: string;
  cd_1: number[];
  cd_2: string[];
}

const result: { [id: string]: Item[]} = {};

data.forEach(function(element){
  if(!result[element.id]) {
    result[element.id] = []
  }
  result[element.id].push(element)
})

console.log(result)

出力結果

{
  'い': [
    { id: 'い', fruits: 'apple', cd_1: [Array], cd_2: [Array] },
    { id: 'い', fruits: 'apple', cd_1: [Array], cd_2: [Array] },
    { id: 'い', fruits: 'apple', cd_1: [Array], cd_2: [Array] }
  ],
  'ろ': [ { id: 'ろ', fruits: 'banana', cd_1: [Array], cd_2: [Array] } ],
  'は': [
    { id: 'は', fruits: 'grape', cd_1: [Array], cd_2: [Array] },
    { id: 'は', fruits: 'grape', cd_1: [Array], cd_2: [Array] },
    { id: 'は', fruits: 'grape', cd_1: [Array], cd_2: [Array] }
  ]
}

cd_1 と cd_2 が[Array]となってしまっていますが、コードの修正方法がわからない状況です。