Translate script values back to NBT when an operator expects NBT

[rubensworks]

Fixes the first half of #67: values that came out of an NBT operator could not be passed into another one. Targeted at master-1.20-lts for upmerging, since the affected code is identical on 1.20, 1.21 and 26 (and on 1.19).

Problem

Only compound tags keep their NBT type when they are translated to a script (they become an NbtCompoundTagProxyObject). Every other tag becomes a plain script value: a list tag or array tag becomes a JS array, primitives become numbers and strings, and an absent NBT value becomes null.

When such a value is passed to an operator again, it is translated back to whatever value type it looks like, so an NBT input receives a list or a number, and OperatorBase.validateTypes rejects it:

const matched = idContext.ops.stringNbtPathMatchFirst('["levels"][?(@ >= 3)]', nbt);
idContext.ops.nbtAsTagList(matched); // operator.integrateddynamics.error.wrong_type [as_tag_list, list, 1, nbt]

A filter expression always matches into a list tag, so this hits every script that post-processes an NBT path match, which is what the reporter ran into. null was worse: no translator handles it, so it failed with valuetype.integratedscripting.error.translation.unknown_from_graal.

Fix

OperatorProxyExecutable now translates each argument against the value type the operator declares for it (CurriedOperator reports the remaining input types, so methods on value proxies work the same way). For an NBT input, a script value that is not NBT is converted with the existing translateToNbt path, and null becomes an absent NBT value. Arguments of every other type keep going through the same translation as before.

Tests

NbtOperatorArgumentsJavaScriptTests covers the list tag round trip, a plain script array, null, and, as controls, a compound tag and a non-NBT argument. Verified that the three NBT tests fail on master-1.20-lts without the fix:

NbtOperatorArgumentsJavaScriptTests > testListTagMatchPassedBackToNbtOperator FAILED
    ...error.wrong_type, args=[as_tag_list, ...list..., 1, ...nbt...]
NbtOperatorArgumentsJavaScriptTests > testArrayPassedToNbtOperator FAILED
    ...error.wrong_type, args=[as_tag_list, ...list..., 1, ...nbt...]
NbtOperatorArgumentsJavaScriptTests > testNullPassedToNbtOperator FAILED
    ...error.translation.unknown_from_graal, args=[null]
5 tests completed, 3 failed

./gradlew build passes with the fix.

Note

The reporter's original call, nbtAsIntList on a filter match, no longer errors but still yields an empty list. That part is on the Integrated Dynamics side: ValueTypeListProxyNbtAsListInt only accepts IntArrayTag, and ValueTypeListProxyNbtAsListGeneric swallows the ClassCastException and reports length 0, so a list tag silently yields nothing. nbtAsTagList is the operator that works for these. Worth a separate look there.

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https://claude.ai/code/session_01JCW1HmWhLT27jh57t9d7B6

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