Quick Edit: Ok I'm one step forward, I realized that $this->user is the currently being edited users' name. So I changed my rules method to this:

    public function rules()
    {
        $user = User::where('name', '=', $this->user)->first();

        return [
            'username'  => ['required', Rule::unique('users', 'name')->ignore($user->id)],
            'email'     => ['required', 'email', Rule::unique('users', 'email')->ignore($user->id)],
        ];
    }

I don't need to use the session anymore. It's still working as far as I can tell. However, would you do it like that?

based on your reply, I tried to view $this->user in my case it contains user id so I do not need to do this query User::where('name', '=', $this->user)->first();

I am not sure how id end up on $this->user when I check other models I get same result for example model Task I get $this->task that contains id, however now unique ignore current user works for email field

thank you

this is my code

<?php

namespace App\Http\Requests\User;

use Illuminate\Foundation\Http\FormRequest;

class UpdateUserRequest extends FormRequest
{
    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        return auth()->user()->can('user-update');
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        return [
            'name' => 'required',
            'email' => 'required|email|unique:users,email,'.$this->user,
            'address' => '',
            'work_number' => 'numeric',
            'personal_number' => 'numeric',
            'password' => 'sometimes',
            'password_confirmation' => 'sometimes',
            'image_path' => 'mimes:jpeg,jpg,png,gif|max:100000',
            'roles' => 'required',
            'departments' => ''
        ];
    }
}

controller action

    /**
     * @param $id
     * @param UpdateUserRequest $request
     * @return mixed
     */
    public function update($id, UpdateUserRequest $request)
    {
        $this->users->update($id, $request);
        Session()->flash('flash_message', 'User successfully updated');
        return redirect()->back();
    }