How can I test that a json is correctly stored?

/** @test */
    public function it_successfuly_registers_for_a_delivery()
    {
        list($user, $program) = $this->arrangeTheWorld();

        $address = 'Full Address';

        $this->visit('program/register')
             ->type($user->first_name, 'first_name')
             ->type($user->last_name, 'last_name')
             ->type($user->email, 'email')
             ->type($user->phone, 'phone')
             ->select($program->id, 'program_id')
             ->select('deliver', 'shipping_method')
             ->type($address, 'shipping_address')
             ->press('Register')
             ->see('Congrats ' . $user->first_name);

        $this->seeInDatabase('users', $user->toArray());

        $this->checkAttendees($program, [
            'shipping_method' => 'deliver',
            'shipping_address' => $address
        ]);

        $this->checkInvoices($program);
    }

/**
     * @return array
     */
    protected function arrangeTheWorld()
    {
        $user = factory(User::class)->make();

        $programs = factory(Program::class, 10)->create([
            'name' => 'Detox5',
            'type' => 'detox5',
            'price' => 65000
        ]);

        $program = $programs->filter(function($program) {
            return $program->start_time > Carbon::now()->addDays(2);
        })[0];

        return [$user, $program];
    }

/**
     * Check the attendees table
     *
     * @param  Program $program
     * @param  array   $extra
     * @return void
     */
    protected function checkAttendees($program, $extra)
    {
        $this->seeInDatabase('attendees', [
            'user_id' => 1,
            'program_id' => $program->id,
            'program_type' => $program->type,
            // 'extra' => json_encode($extra)
        ]);
    }

If I check for an array in the DB or json encode it it still doesn't return a green test. With it commented out it gives me a green test.