JsonNode.deepCopy() ClassCastException`s #1829
Description
The current signature of JsonNode#deepCopy looks like this:
public abstract <T extends JsonNode> T deepCopy();
I wondered about the decision to do this as you can quite easily create a ClassCastException using this as follows:
TextNode text = TextNode.valueOf("SomeText");
ObjectNode object = text.deepCopy();
This code is obviously incorrect just by looking at it however this will always compile and throw an exception at runtime. I know this is considered an API change but a signature that prevents this might be:
JsonNode.java
public abstract JsonNode deepCopy();
And then be overridden on each subclass with the correct type
ValueNode.java
public abstract ValueNode deepCopy();
After looking at this again, the signatures of ObjectNode and ArrayNode are correct but you can still trick it by upcasting to JsonNode and then using deepCopy()