Declare tool harvest level as a property

src/pocketmine/block/Block.php

@@ -195,14 +195,26 @@ class Block extends Position implements BlockIds, Metadatable{
 		return true;
 	}
 
+	/**
+	 * @return int
+	 */
+	public function getToolType() : int{
+		return BlockToolType::TYPE_NONE;
+	}
+
+	public function getToolHarvestLevel() : int{
+		return 0;
+	}
+
 	public function canBeBrokenWith(Item $item) : bool{
 		if($this->getHardness() < 0){
 			return false;
 		}
 
 		$toolType = $this->getToolType();
-		return $toolType === BlockToolType::TYPE_NONE or ($toolType & $item->getBlockToolType()) !== 0;
+		$harvestLevel = $this->getToolHarvestLevel();
-		//TODO: check tool harvest level (tier)
+		return $toolType === BlockToolType::TYPE_NONE or $harvestLevel === 0 or (
+			($toolType & $item->getBlockToolType()) !== 0 and $item->getBlockToolHarvestLevel() >= $harvestLevel);
 	}
 
 	/**
@@ -319,13 +331,6 @@ class Block extends Position implements BlockIds, Metadatable{
 		return $this->getHardness() * 5;
 	}
 
-	/**
-	 * @return int
-	 */
-	public function getToolType() : int{
-		return BlockToolType::TYPE_NONE;
-	}
-
 	/**
 	 * @return float
 	 */

src/pocketmine/item/Axe.php

@@ -35,6 +35,10 @@ class Axe extends TieredTool{
 		return BlockToolType::TYPE_AXE;
 	}
 
+	public function getBlockToolHarvestLevel() : int{
+		return $this->tier;
+	}
+
 	public function getAttackPoints() : int{
 		return self::getBaseDamageFromTier($this->tier) - 1;
 	}

src/pocketmine/item/Item.php

@@ -752,6 +752,10 @@ class Item implements ItemIds, \JsonSerializable{
 		return BlockToolType::TYPE_NONE;
 	}
 
+	public function getBlockToolHarvestLevel() : int{
+		return 0;
+	}
+
 	/**
 	 * Returns the maximum amount of damage this item can take before it breaks.
 	 *

src/pocketmine/item/Pickaxe.php

@@ -35,6 +35,10 @@ class Pickaxe extends TieredTool{
 		return BlockToolType::TYPE_PICKAXE;
 	}
 
+	public function getBlockToolHarvestLevel() : int{
+		return $this->tier;
+	}
+
 	public function getAttackPoints() : int{
 		return self::getBaseDamageFromTier($this->tier) - 2;
 	}

src/pocketmine/item/Shears.php

@@ -42,4 +42,8 @@ class Shears extends Tool{
 	public function getBlockToolType() : int{
 		return BlockToolType::TYPE_SHEARS;
 	}
+
+	public function getBlockToolHarvestLevel() : int{
+		return 1;
+	}
 }

src/pocketmine/item/Shovel.php

@@ -35,6 +35,10 @@ class Shovel extends TieredTool{
 		return BlockToolType::TYPE_SHOVEL;
 	}
 
+	public function getBlockToolHarvestLevel() : int{
+		return $this->tier;
+	}
+
 	public function getAttackPoints() : int{
 		return self::getBaseDamageFromTier($this->tier) - 3;
 	}

src/pocketmine/item/Sword.php

@@ -39,4 +39,7 @@ class Sword extends TieredTool{
 		return self::getBaseDamageFromTier($this->tier);
 	}
 
+	public function getBlockToolHarvestLevel() : int{
+		return 1;
+	}
 }