Laravelの FormRequestでのバリデーション結果後のエラーをpostされたJSON構造と同じ構造で返却したい

Laravel 8系において
JSONd形式のデータをVue.jsのaxiosでPOSTした際､
FormRequestを経由したバリデーションエラーをPOSTされたjsonデータの階層構造と同じ構造で返却したい｡

php
1
2<?php
3
4namespace App\Http\Requests\Api;
5
6use Illuminate\Support\Facades\Route;
7use Illuminate\Foundation\Http\FormRequest;
8use Illuminate\Validation\Rule;
9use Illuminate\Http\Exceptions\HttpResponseException;
10use Illuminate\Contracts\Validation\Validator;
11
12class ServiceRequest extends BaseRequest
13{
14    /**
15     * Determine if the user is authorized to make this request.
16     *
17     * @return bool
18     */
19    public function authorize()
20    {
21        return true;
22    }
23
24    /**
25     * Get the validation rules that apply to the request.
26     *
27     * @return array
28     */
29    public function rules()
30    {
31
32        $rules = [];
33        $route_name = Route::currentRouteName();
34        $method = strtoupper($this->getMethod());
35
36        if ($method === "POST") {
37
38            // 新規サービス登録
39            if ($route_name === "api.front.service.create") {
40                $rules = [
41                    "owner_id" => [
42                        "required",
43                        "integer",
44                        Rule::exists("owners", "id"),
45                    ],
46                    "service_name" => [
47                        "required",
48                        "string",
49                        "between:1,512"
50                    ],
51                    "memo" => [
52                        "nullable",
53                        "string",
54                        "between:0,10240"
55                    ],
56                    // 当該のサービスが収容できる人数
57                    "capacity" => [
58                        "required",
59                        "integer",
60                        "min:1",
61                    ],
62                    // 統一価格
63                    "price" => [
64                        "required",
65                        "integer",
66                    ],
67                    // 時間単価(時給)
68                    "price_per_hour" => [
69                        "required",
70                        "integer",
71                    ],
72                    "service_type" => [
73                        "required",
74                        "integer",
75                        Rule::in(array_column(Config("const.service_types"), "index"))
76                    ],
77                    "reservable_times" => [
78                        "required",
79                        "array",
80                    ],
81                    "reservable_times.*" => [
82                        "required",
83                        "array",
84                    ],
85                    "reservable_times.*.reservable_date" => [
86                        "required",
87                        "integer",
88                        Rule::in(array_column(Config("const.reservable_dates"), "index")),
89                    ],
90                    "reservable_times.*.reservable_from" => [
91                        // 予約可能開始時間
92                        "required",
93                        // Rule::in(Config("const.reservable_hours")),
94                    ],
95                    "reservable_times.*.reservable_to" => [
96                        // 予約可能終了時間
97                        "required",
98                        // Rule::in(Config("const.reservable_minutes")),
99                    ],
100                ];
101            }
102        }
103        return $rules;
104    }
105}
106

上記のようなFormRequestクラスを作成し､下記のようなJSONデータをaxios経由でPOSTします｡

javascript
1// APIサーバとして稼働しているLaravelへ以下をPOST
2{
3    "service_images": [],
4    "reservable_times": [
5        {
6            "reservable_date": "",
7            "reservable_from": "",
8            "reservable_to": "",
9            "reservable_from_hour": "",
10            "reservable_from_minute": "",
11            "reservable_to_hour": "",
12            "reservable_to_minute": ""
13        }
14    ],
15    "owner_id": 1
16}

すると､FormRequestクラスを通して
以下のようなバリデーションエラーが取得できました｡

javascript
1{
2    "service_name": [
3        "The service name field is required."
4    ],
5    "capacity": [
6        "The capacity field is required."
7    ],
8    "price": [
9        "The price field is required."
10    ],
11    "price_per_hour": [
12        "The price per hour field is required."
13    ],
14    "service_type": [
15        "The service type field is required."
16    ],
17    "reservable_times.0.reservable_date": [
18        "The reservable_times.0.reservable_date field is required."
19    ],
20    "reservable_times.0.reservable_from": [
21        "The reservable_times.0.reservable_from field is required."
22    ],
23    "reservable_times.0.reservable_to": [
24        "The reservable_times.0.reservable_to field is required."
25    ]
26}

そこで､現在困っている点が､postデータであるjsonの中に [reservable_times]というキーにぶら下がる配列の箇所が､
元のJSONの階層を維持せず一次元の配列にフォーマットされてしまっている点です｡

これだと､フロント側のVue.jsでエラー表示する際の処理に不都合しか無いので､
上記のレスポンスを

javascript
1{
2    "service_name": [
3        "The service name field is required."
4    ],
5    "capacity": [
6        "The capacity field is required."
7    ],
8    "price": [
9        "The price field is required."
10    ],
11    "price_per_hour": [
12        "The price per hour field is required."
13    ],
14    "service_type": [
15        "The service type field is required."
16    ],
17    "reservable_times": [
18        {
19            "reservable_date": [
20                "The reservable_times.0.reservable_date field is required."
21            ],
22            "reservable_from": [
23                "The reservable_times.0.reservable_from field is required."
24            ],
25            "reservable_to": [
26                "The reservable_times.0.reservable_to field is required."
27            ]
28        }
29    ]
30}