v2board/app/Http/Requests/Passport/LoginIndex.php

<?php

namespace App\Http\Requests\Passport;

use Illuminate\Foundation\Http\FormRequest;

class LoginIndex extends FormRequest
{
    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        return [
            'email' => 'required|email',
            'password' => 'required|min:8'
        ];
    }

    public function messages()
    {
        return [
            'email.required' => '邮箱不能为空',
            'email.email' => '邮箱格式不正确',
            'password.required' => '密码不能为空',
            'password.min' => '密码必须大于8位数'
        ];
    }
}