use Illuminate\Http\Request;
use Illuminate\Support\Facades\Route;
use Illuminate\Validation\Rule;
use Illuminate\Validation\Rules\Password;

Route::post('/valid/basic', function (Request $request) {
    $validated = $request->validate([
        'name' => ['required', 'string', 'max:20'],
        'email' => ['required', 'email', 'unique:users,email'],
        'age' => ['required', 'integer', 'between:0,120'],
        'plan' => ['required', Rule::in(['free', 'pro'])],
        'website' => ['nullable', 'url'],
        'start_date' => ['required', 'date', 'after:today'],
        'password' => ['required', 'confirmed', Password::min(8)->letters()->numbers()],
    ]);

    return response()->json(['validated' => $validated]);
});

curl -X POST http://localhost:8000/valid/basic \
  -H 'Content-Type: application/json' -H 'Accept: application/json' \
  -d '{}'

{
    "message": "The name field is required. (and 5 more errors)",
    "errors": {
        "name": [
            "The name field is required."
        ],
        "email": [
            "The email field is required."
        ],
        "age": [
            "The age field is required."
        ],
        "plan": [
            "The plan field is required."
        ],
        "start_date": [
            "The start date field is required."
        ],
        "password": [
            "The password field is required."
        ]
    }
}

{
    "name": "あいうえおかきくけこさしすせそたちつてとな",
    "email": "[email protected]",
    "age": "二十",
    "plan": "gold",
    "website": "",
    "start_date": "2020-01-01",
    "password": "abc",
    "password_confirmation": "abd"
}

{
    "message": "The name field must not be greater than 20 characters. (and 7 more errors)",
    "errors": {
        "name": [
            "The name field must not be greater than 20 characters."
        ],
        "email": [
            "The email has already been taken."
        ],
        "age": [
            "The age field must be an integer."
        ],
        "plan": [
            "The selected plan is invalid."
        ],
        "start_date": [
            "The start date field must be a date after today."
        ],
        "password": [
            "The password field confirmation does not match.",
            "The password field must be at least 8 characters.",
            "The password field must contain at least one number."
        ]
    }
}

{
    "name": "ララテック",
    "email": "[email protected]",
    "age": 30,
    "plan": "pro",
    "website": null,
    "start_date": "2030-01-01",
    "password": "secret123",
    "password_confirmation": "secret123",
    "is_admin": true
}

{
    "validated": {
        "name": "ララテック",
        "email": "[email protected]",
        "age": 30,
        "plan": "pro",
        "website": null,
        "start_date": "2030-01-01",
        "password": "secret123"
    }
}

$validated = $request->validate([
    'tags' => ['required', 'array', 'max:3'],
    'tags.*' => ['string', 'distinct', 'max:10'],
    'items' => ['array'],
    'items.*.name' => ['required', 'string'],
    'items.*.qty' => ['required', 'integer', 'min:1'],
]);

{
    "tags": ["php", "php", "laravel", "vue"],
    "items": [
        {"name": "りんご", "qty": 2},
        {"qty": 0}
    ]
}

{
    "message": "The tags field must not have more than 3 items. (and 4 more errors)",
    "errors": {
        "tags": [
            "The tags field must not have more than 3 items."
        ],
        "tags.0": [
            "The tags.0 field has a duplicate value."
        ],
        "tags.1": [
            "The tags.1 field has a duplicate value."
        ],
        "items.1.name": [
            "The items.1.name field is required."
        ],
        "items.1.qty": [
            "The items.1.qty field must be at least 1."
        ]
    }
}

// bail なし
$request->validate(['code' => ['integer', 'digits:4', 'starts_with:9']]);

// bail あり
$request->validate(['code' => ['bail', 'integer', 'digits:4', 'starts_with:9']]);

"code": [
    "The code field must be an integer.",
    "The code field must be 4 digits.",
    "The code field must start with one of the following: 9."
]

"code": [
    "The code field must be an integer."
]

php artisan make:request StoreMemberRequest

<?php

namespace App\Http\Requests;

use Illuminate\Foundation\Http\FormRequest;

class StoreMemberRequest extends FormRequest
{
    public function authorize(): bool
    {
        return true;
    }

    public function rules(): array
    {
        return [
            'name' => ['required', 'string', 'max:20'],
            'email' => ['required', 'email'],
        ];
    }

    public function messages(): array
    {
        return [
            'required' => ':attributeを入力してください。',
            'name.max' => ':attributeは:max文字以内で入力してください。',
            'email.email' => ':attributeの形式が正しくありません。',
        ];
    }

    public function attributes(): array
    {
        return [
            'name' => '名前',
            'email' => 'メールアドレス',
        ];
    }
}

{
    "message": "This action is unauthorized."
}

use App\Http\Requests\StoreMemberRequest;

Route::post('/valid/member', function (StoreMemberRequest $request) {
    return response()->json(['validated' => $request->validated()]);
});

{
    "message": "名前を入力してください。 (and 1 more error)",
    "errors": {
        "name": [
            "名前を入力してください。"
        ],
        "email": [
            "メールアドレスを入力してください。"
        ]
    }
}

{
    "message": "名前は20文字以内で入力してください。 (and 1 more error)",
    "errors": {
        "name": [
            "名前は20文字以内で入力してください。"
        ],
        "email": [
            "メールアドレスの形式が正しくありません。"
        ]
    }
}

HTTP/1.1 302 Found
Location: http://localhost:8000/form

<form method="POST" action="/valid/member">
  @csrf
  <input name="name" value="{{ old('name') }}">
  @error('name')
    <p class="error">{{ $message }}</p>
  @enderror
  <input name="email" value="{{ old('email') }}">
  @error('email')
    <p class="error">{{ $message }}</p>
  @enderror
  <button>送信</button>
</form>

<input name="name" value="">
  <p class="error">名前を入力してください。</p>
<input name="email" value="abc">
  <p class="error">メールアドレスの形式が正しくありません。</p>