ParseNBT.js

 ParseNBT.js is a JavaScript-based minecraft NBT parser and serializer.

Install

npm i parsenbt-js

Usage

Reader

const fs = require('fs'), NBT = require('parsenbt-js');

var binData = fs.readFileSync('./path/of/nbt.nbt');
// The NBT.Reaer returns an object
console.log(NBT.Reader(binData));

Writer

const fs = require('fs'), NBT = require('parsenbt-js');

var nbtData = {
  "comp>": {
    "i32>count": 100,
    "list>pos": [ "i32", 0, 0, 0 ],
    "i64>ticks": { "low": 114514, "high": 1919810 }
  }
};

// The NBT.Writer returns a buffer
// The second param determined the byte order
// little-endian if it's true
console.log(NBT.Writer(nbtData, !0));

API

See API.md

Data Structure

 ParseNBT.js' output uses a special data structure for keys of the object.
 For example:

{
  "comp>": { 
    "i32>count": 100,
    "list>pos": [ "i32", 0, 0, 0 ],
    "i64>ticks": { "low": 114514, "high": 1919810 }
  }
}

 In the object, keys are separated into two parts with character >.  In the left-hand-side is the tag type, and the right-hand-side is the tag name. Tag name can be an empty string like above.
 The comparison table between the type string and the actual type is as follows:

Tag ID	Tag Type	Tag Type String
0	TAG_End	null
1	TAG_Byte	i8
2	TAG_Short	i16
3	TAG_Int	i32
4	TAG_Long	i64
5	TAG_Float	f32
6	TAG_Double	f64
7	TAG_Byte_Array	a8
8	TAG_String	str
9	TAG_List	list
10	TAG_Compound	comp
11	TAG_Int_Array	a32
12	TAG_Long_Array	a64

 Especially, the type of elements in TAG_List is at the first element of the list array. And for TAG_Long, it'll be formatted into an object which has two values named low and high, that produces the high 32 bits and the low 32 bits separately.