Chain call crash in Python-JavaScript bridge when accessing object properties.

Context: The bug occurs when using the Python-JavaScript bridge and the mineflayer module.
Replay conditions: The crash occurs when methods are called in a chain, e.g. playerEntity.position.offset(...).

from javascript import require, On
mineflayer = require('mineflayer')

bot = mineflayer.createBot({
  'host': 'localhost',
  'port': 30034,
  'username': 'lookAt_Bot'
})

def lookAtNearestPlayer():
    playerEntity = bot.nearestEntity()
  
    if not playerEntity: 
        return
  
    pos = playerEntity.position.offset(0, playerEntity.height, 0)
    bot.lookAt(pos)
    
@On(bot, 'chat')
def chathandle(this, username, message, *args):
    if username == "sffkjsdfsfd" and message == "asdkasdjkadjskajsdj":
        bot.chat('asjdkjasdkasjd')

@On(bot, 'physicsTick')
def handle(*args):
    lookAtNearestPlayer()

Workaround: Assigning an intermediate value to a variable before calling a method prevents a crash.

pos = playerEntity.position
pos = pos.offset(0, playerEntity.height, 0)
bot.lookAt(pos)

• Funny enough, "@on(bot, 'chat')" also affects the bug. If you remove this event, the script will not crash.
• The script crashes on chat messages (even though the event should not affect anything), but I don't think this applies to JSPyBridge.

JS analog

const mineflayer = require('mineflayer')

const bot = mineflayer.createBot({
  host: 'localhost',
  port: 37269,
  username: 'lookAt_Bot'
})

function lookAtNearestPlayer () {
  const playerFilter = (entity) => entity.type === 'player'
  const playerEntity = bot.nearestEntity(playerFilter)
  
  if (!playerEntity) return
  
  const pos = playerEntity.position.offset(0, playerEntity.height, 0)
  bot.lookAt(pos)
}

bot.on('physicTick', lookAtNearestPlayer)

the screenshot and log are old, but the error is the same.

Error: https://imgur.com/Ww9h3ci
PrismarineJS/mineflayer#2996 (comment)

C:\Users\root\Desktop>python main.py [JSE] node:internal/process/promises:288 [JSE]             triggerUncaughtException(err, true /* fromPromise */); [JSE]             ^ [JSE] [JSE] [🐍  Python Error  JavaScript attempt to call 'some function' in Python failed: [JSE] > bot.emit('physicsTick') [JSE]   at Timeout.doPhysics [as _onTimeout] (C:\Users\root\AppData\Local\Programs\Python\Python39\lib\site-packages\javascript\js\node_modules\mineflayer\lib\plugins\physics.js:65:13) [JSE]   at listOnTimeout (node:internal/timers:569:17) [JSE]   at process.processTimers (node:internal/timers:512:7) [JSE] [JSE] ... across the bridge ... [JSE] [JSE] > lookAtNearestPlayer() [JSE]   at handle (C:\Users\root\Desktop\main.py:26) [JSE] > pos = playerEntity.position.offset(0, playerEntity.height, 0) [JSE]   at lookAtNearestPlayer (C:\Users\root\Desktop\main.py:16) [JSE] 🌉 javascript.errors.JavaScriptError: ('offset', "TypeError: Cannot read properties of undefined (reading 'offset')\n    at Bridge.call (C:\\Users\\root\\AppData\\Local\\Programs\\Python\\Python39\\lib\\site-packages\\javascript\\js\\bridge.js:136:35)\n    at Bridge.onMessage (C:\\Users\\root\\AppData\\Local\\Programs\\Python\\Python39\\lib\\site-packages\\javascript\\js\\bridge.js:226:25)\n    at Socket.<anonymous> (C:\\Users\\root\\AppData\\Local\\Programs\\Python\\Python39\\lib\\site-packages\\javascript\\js\\bridge.js:278:18)\n    at Socket.emit (node:events:513:28)\n    at addChunk (node:internal/streams/readable:324:12)\n    at readableAddChunk (node:internal/streams/readable:297:9)\n    at Readable.push (node:internal/streams/readable:234:10)\n    at Pipe.onStreamRead (node:internal/stream_base_commons:190:23)")] [JSE] [JSE] Node.js v18.15.0

@extremeheat

@extremeheat

[mk-pmb]

Request to close since OP has ghosted us.
Also not worth entertaining the original request since what they described as "workaround" is actually just good practice, so everyone should use that "workaround" anyways.