pocketmine\item\Tool::useOn PHP Method

    public function useOn($object, $type = 1)
    {
        if ($this->isUnbreakable()) {
            return true;
        }
        $unbreakingl = $this->getEnchantmentLevel(Enchantment::TYPE_MINING_DURABILITY);
        $unbreakingl = $unbreakingl > 3 ? 3 : $unbreakingl;
        if (mt_rand(1, $unbreakingl + 1) !== 1) {
            return true;
        }
        if ($type === 1) {
            if ($object instanceof Entity) {
                if ($this->isHoe() !== false or $this->isSword() !== false) {
                    //Hoe and Sword
                    $this->meta++;
                    return true;
                } elseif ($this->isPickaxe() !== false or $this->isAxe() !== false or $this->isShovel() !== false) {
                    //Pickaxe Axe and Shovel
                    $this->meta += 2;
                    return true;
                }
                return true;
                //Other tool do not lost durability white hitting
            } elseif ($object instanceof Block) {
                if ($this->isShears() !== false) {
                    if ($object->getToolType() === Tool::TYPE_SHEARS) {
                        //This should be checked in each block
                        $this->meta++;
                    }
                    return true;
                } elseif ($object->getHardness() > 0) {
                    //Sword Pickaxe Axe and Shovel
                    if ($this->isSword() !== false) {
                        $this->meta += 2;
                        return true;
                    } elseif ($this->isPickaxe() !== false or $this->isAxe() !== false or $this->isShovel() !== false) {
                        $this->meta += 1;
                        return true;
                    }
                }
            }
        } elseif ($type === 2) {
            //For Touch. only trigger when OnActivate return true
            if ($this->isHoe() !== false or $this->id === self::FLINT_STEEL or $this->isShovel() !== false) {
                $this->meta++;
                return true;
            }
        }
        return true;
    }