How to edit HTML game files

decoder.js

/*
  This will take a .save game file, decode it into its JSON form,
  and then save it to game-data.json
*/
const fs = require('fs');
const LZString = require('lz-string');

if (process.argv.length === 3) {
  try {
    const encodedData = fs.readFileSync(process.argv[2], 'utf8');
    const extractedData = LZString.decompressFromBase64(encodedData);
    fs.writeFileSync('game-data.json', extractedData);
    console.log('All done :)');
  } catch (error) {
    console.log("That didn't work...");
    console.log(error);
  }
} else {
  console.log('usage: node decoder.js [.save file]');
}

encoder.js

/*
  This will read the game-data.json file, encode it, and save that into mygame.save
*/
const fs = require('fs');
const LZString = require('lz-string');

try {
  const contents = fs.readFileSync('game-data.json', 'utf8');
  const dataToSave = LZString.compressToBase64(contents);
  fs.writeFileSync('mygame.save', JSON.stringify(dataToSave));
  console.log('All done :)');
} catch (error) {
  console.log("That didn't work...");
  console.log(error);
}

[LOCAL_DATA_INFO]
local_mac_addr = B6:9D:02:4D:0D:15
key_send_bankruptcy_208365691 = 0
last_login_userid = 208365691
key_local_first_login_time_208365691 = 1651084998
key_local_today_game_time_208365691 = 0
key_local_login_day_208365691 = 5
login_guest_userid = 208365691
login_guest_code = oFW9v053mZR3W6A6C862LnWW4104D7hX
last_login_type = 2
key_free_get_rose_last_update_time_208365691 = 1651084999
key_free_get_rose_online_time_208365691 = 30
key_show_first_vac_208365691 = 0
key_show_off_yd_1_208365691 = 0
key_show_off_yd_2_208365691 = 0
key_show_off_yd_3_208365691 = 0
key_into_free_room_208365691 = 0
sys_atuo_game_first = 1
lobby_vip_type = 96
key_lobby_last_enter_game = 10
key_free_get_rose_online_time_87372127 = 30
key_send_bankruptcy_203704921 = 0
key_local_first_login_time_203704921 = 1647620411
key_local_today_game_time_203704921 = 0
key_local_login_day_203704921 = 23
hw_account_id_0 = 203704921
hw_account_password_0 = AF17E2EE190B406CE9DE509B5E9A4742D675F6E946D0
hw_account_type_0 = 1
hw_account_id_1 = 87372127
hw_account_password_1 = AF17E2EE190B406CE9DE509B5E9A4742D675F6E946D0
hw_account_type_1 = 1
hw_account_id_2 =
hw_account_password_2 =
hw_account_type_2 = -1
hw_account_id_3 =
hw_account_password_3 =
hw_account_type_3 = -1
key_free_get_rose_last_update_time_203704921 = 1647620412
key_free_get_rose_online_time_203704921 = 90
key_friend_yd_203704921 = 0
key_into_free_room_203704921 = 0
key_item_mall_yd_203704921 = 1
show_cz_libao_type_203704921 = 2
get_relief_num_203704921 = 4
key_show_first_vac_203704921 = 0
key_show_off_yd_1_203704921 = 0
key_show_off_yd_2_203704921 = 0
key_show_off_yd_3_203704921 = 0
key_last_CharmWeekRankIssue_203704921 = 20220110
key_item_mall_yd_208365691 = 1