Issue Description:

When using IItemStack.addAdvancedTooltip(ITooltipFunction), the tooltip function documentation says that the parameter passed will be the IItemStack that the tooltip is being generated for (which also makes sense) but an in-game /ct syntax says that it passes an IIngredient instead (which doesn't) despite both the function and the function's parameter being type-specified.

What happens:

If my tooltip function tries to access NBT data via the tag zengetter on the parameter directly, I get no such member in crafttweaker.item.IIngredient: tag pointing to the line in question. If I treat it as an ingredient and use .itemArray[0] then the script (sometimes) works, and doesn't log any errors. At worst, it just doesn't add any tooltip text for some reason.

This happens regardless of whether I declare the function to be as ITooltipFunction, by the way.

What you expected to happen:

Either the parameter to be passed as an IItemStack or an error to be thrown when I declare that the parameter is expected to be an IItemStack.

Script used (Please Pastebin or gist your script, posting an unpasted or ungist'd script will automatically close this issue):

Entire script here. The bit you actually want starts on line 200. The specific issue is on line 215 - if I use item.itemArray[0] then it (sometimes) works and I don't get errors; if I try item alone, I get the described error.

crafttweaker.log file (Please Pastebin or gist your file, posting an unpasted or ungist'd file will automatically close this issue):

Pastebin

Affected Versions (Do not use "latest"):

• Minecraft: 1.12.2
• Forge: 14.23.5.2847
• Crafttweaker: 1.12-4.1.15
• Using a server: singleplayer integrated server only
• If yes, does the client have the exact same scripts?

Your most recent log file where the issue was present:

latest.log

I have no idea what's going on with my script, then. If I remove the import for the ITooltipFunction and don't cast the function, it complains that it can't find the ITooltipFunction type. If I leave the import line in but don't cast, it doesn't do that, but /ct syntax seems to think that item inside the function is an IIngredient, even though it's also declared as an IItemStack explicitly. What's worse is that I pasted your exact code at the end of my script file, and I got the same error - no such member in crafttweaker.item.IIngredient: tag - when I run /ct syntax again. I even added a new file, test.zs, that has nothing but the import for the IItemStack type and the your code, and the syntax command throws me the same error. The entire file is just:

import crafttweaker.item.IItemStack;
<minecraft:diamond>.addAdvancedTooltip(function(item as IItemStack) {
	if !isNull(item.tag){
		return item.tag as string;
	}
	return "no tag";
});

Is /ct syntax somehow doing something different than normal game-init loading?

I'm having trouble reproducing this, using:

<minecraft:diamond>.addAdvancedTooltip(function(item as IItemStack) {
        if !isNull(item.tag){
            return item.tag as string;
        }
        return "no tag";
    });

shows {} in-game, as it has an empty tag (I assume), but it doesn't crash.

Using a custom global function to print the object type:

    <minecraft:diamond>.addAdvancedTooltip(function(item as IItemStack) {
                return typeof(item);
        });

produces:

crafttweaker.mc1120.item.MCItemStack

So I'm really not sure what is going on here, but I'm fairly sure the JVM would complain if we somehow passed and IIngredient to an IItemStack param.