Minecraft Command NBT Array Add

Question

I'm having (for example) a entity (Drop) with this NBT:

{Item:{tag:{display:{Lore:["test1"]}},id:"minecraft:bread"}}

I'm trying to add a new lore:

/data merge entity @e[type=item,tag=myDrop] {Item:{tag:{display:{Lore:["test2"]}}}}

But when I execute this and collect my drop there is ONLY test2 as lore but i need test1 and test2. Please help! Thanks.

EDIT: I don't know the content and/or the count of test1.

EDIT2: So simply a array.append() but how in minecraft?

Answer 1

1.14 introduces this feature using the "append" mode of /data modify:

/data modify entity @e[type=item,limit=1] Item.tag.display.Lore append value "{\"text\":\"second line\"}"

Answer 2

Try

/data merge entity @e[type=item,limit=1] {Item:{tag:{display:{Lore:["test2","test1"]}}}}

You're still replacing the original test1, but you can just replace it with test1, or you could change it.

Hope this helps! :D