The /enchant command can execute successfully at level zero, and will do nothing to the item

The /enchant command can be used to enchant items with a level of 0, when it should only succeed at a level of 1 or more.

Steps to Reproduce:

1. Hold an un-enchanted tool in your main-hand
2. Run the following command:

   /enchant @p minecraft:unbreaking 0
   

Expected Result:

The command would fail — showing a command in chat, and do nothing to the item.

Observed Result:

The command acts as though it succeeded, sending a message in chat. Nothing will happen to the item, and it will remain un-enchanted.