Item can be `undefined` in Chapter 2.3

[shinebayar-g]

Hi first of all i must say thanks to author for this awesome guide. I was following chapters one by one and here I'm at chapter 2.3 everything was working as intended until this part:

I don't think it's mandatory, but just fyi :D

function sendRandomItem() {
  const partner = 'partner_steam_id'; #Note: I used your_trusted_account_id here as mentioned in Chapter 2.2
  const appid = 440; #Note: I tried both app id 440 (TF2) and 730 (CSGO), PS: My bot has CSGO purchased, Trusted account didn't buy CSGO. But trade with CSGO items were working.
  const contextid = 2;

  const offer = manager.createOffer(partner);

  manager.loadInventory(appid, contextid, true, (err, myInv) => {
    if (err) {
      console.log(err);
    } else {
      const myItem = myInv[Math.floor(Math.random() * myInv.length - 1)];
      offer.addMyItem(myItem);

      manager.loadUserInventory(
        partner,
        appid,
        contextid,
        true,
        (err, theirInv) => {
          if (err) {
            console.log(err);
          } else {
            const theirItem =
              theirInv[Math.floor(Math.random() * theirInv.length - 1)];
            offer.addTheirItem(theirItem);

            offer.setMessage(
              `Will you trade your ${theirItem.name} for my ${myItem.name}?`
            );
            offer.send((err, status) => {
              if (err) {
                console.log(err);
              } else {
                console.log(`Sent offer. Status: ${status}.`);
              }
            });
          }
        }
      );
    }
  });
}

this part of code giving the following result:

Logged into Steam
c:\Node\node_modules\steam-tradeoffer-manager\lib\classes\TradeOffer.js:254
        if (typeof details.appid === 'undefined' || typeof details.contextid === 'undefined' || (typeof details.assetid === 'undefined' && typeof details.id === 'undefined')) {
                           ^

TypeError: Cannot read property 'appid' of undefined
    at addItem (c:\Node\node_modules\steam-tradeoffer-manager\lib\classes\TradeOffer.js:254:21)
    at TradeOffer.addMyItem (c:\Node\node_modules\steam-tradeoffer-manager\lib\classes\TradeOffer.js:167:9)
    at manager.loadInventory (c:\Node\project2.js:70:13)
    at SteamCommunity.<anonymous> (c:\Node\node_modules\steamcommunity\components\users.js:342:5)
    at Request._callback (c:\Node\node_modules\steamcommunity\components\http.js:67:15)
    at Request.self.callback (c:\Node\node_modules\request\request.js:186:22)
    at emitTwo (events.js:126:13)
    at Request.emit (events.js:214:7)
    at Request.<anonymous> (c:\Node\node_modules\request\request.js:1163:10)
    at emitOne (events.js:116:13)

[DentFuse]

Are you sure you have provided the part of the code which errors? Cause I can't see any if conditions in ur provided code, also you haven't defined details, that might be the problem.

[urumo]

same problem here, decided to copy the codi from the repo, got the same error

[andrewda]

https://dev.doctormckay.com/topic/885-typeerror-cannot-read-property-appid-of-undefined/

We should check to ensure the inventory isn't empty first.

[TheDefective]

Sorry to revive a dead thread but I had this same issue but removed the -1 from the inventory length and it worked