ShortcutsVdfReader.mjs

import {readFileSync} from "fs";

const ObjectType = {
    Map: 0,
    String: 1,
    Int32: 2
};

class Reader {
    constructor(content) {
        this.content = content;
        this.index = 0;
    }

    hasMore() {
        return this.index < this.content.length;
    }

    peekByte() {
        if(!this.hasMore())
            throw new Error("EOF");

        return this.content[this.index];
    }

    readByte() {
        if(!this.hasMore())
            throw new Error("EOF");

        const ret = this.content[this.index];
        this.index++;
        return ret;
    }

    readNullTerminatedString() {
        let nullFound = false;
        let ret = "";
        while(!nullFound && this.hasMore()) {
            let byte = this.readByte();

            if(byte === 0) {
                nullFound = true;
                continue;
            }

            ret += String.fromCharCode(byte);
        }

        if(!nullFound)
            throw new Error("EOF When reading null-terminating string");

        return ret;
    }

    readInt16() {
        return this.readByte() << 8 | this.readByte();
    }

    readInt32() {
        const ret = this.content.readUIntLE(this.index, 4);
        this.index += 4;
        return ret;
    }

    readMapKV() {
        const objectType = this.readByte();
        const keyName = this.readNullTerminatedString();
        let value;

        switch(objectType) {
            case ObjectType.Map:
                value = this.readMap();
                break;
            case ObjectType.Int32:
                value = this.readInt32();
                break;
            case ObjectType.String:
                value = this.readNullTerminatedString();
                break;
            default:
                console.log("Unknown object type " + objectType);
        }

        return {key: keyName, value};
    }

    readMap() {
        const ret = {};

        while(this.hasMore() && this.peekByte() !== 8) {
            const kv = this.readMapKV();
            ret[kv.key] = kv.value;
        }

        if(!this.hasMore())
            throw new Error("EOF - expecting map terminator (0x08)");

        this.readByte(); //Consume 0x08

        return ret;
    }
}
/**
 *
 * @param path {String}
 * @return {any}
 */
function parse(path) {
    const reader = new Reader(readFileSync(path));

    return reader.readMap();
}

console.log(JSON.stringify(parse("C:\\Program Files (x86)\Steam\\userdata\\USERIDHERE\\config\\shortcuts.vdf"), null, 4));