Weird Issue on single message thread.

[Ionshard]

I attempted to implement the snoozever script and I was getting empty notes titled "To do from inbox - "

Now I throw some logging in.
Given

  /***********************************************
  * ACTION
  ***********************************************/

  // Get snoozed threads
  var threads = GmailApp.search('label:snoozed');


  // Loop of snoozed threads
  for(i in threads){

    // Get last message of threads
    var message = threads[i].getMessages()[threads[i].getMessageCount()-1];

    Logger.log('Message Count ' + threads[i].getMessageCount());
    Logger.log('Last Index ' + (threads[i].getMessageCount()-1));
    Logger.log('Subject ' + message.getSubject());

//    //Forward last message to evernote
//    message.forward(evernoteEmail, {
//      subject: 'Email: '+message.getSubject()+' '+tags+' '+notebook
//    });
//
//    // Mark thread as done
//     GmailApp.moveThreadToArchive(threads[i]);

I get the following logs

[15-08-20 15:27:19:415 EDT] Message Count 2
[15-08-20 15:27:19:416 EDT] Last Index 1
[15-08-20 15:27:19:416 EDT] Subject 

I change the following code (I'm no javascript expert) so I don't know why this worked.

   // Get last message of threads
    var last_index = threads[i].getMessageCount()-1;
    var message = threads[i].getMessages()[last_index];

Which results in finding the correct message

[15-08-20 15:31:06:603 EDT] Message Count 2
[15-08-20 15:31:06:604 EDT] Last Index 1
[15-08-20 15:31:06:605 EDT] Subject Your official start time and important event information for Tough Mudder Pittsburgh

I don't know if others are having this issue but figured I'd let you know. Again that shouldn't have fixed anything but I can revert it and see the exact issue again.

[sandoche]

That's quite weird, I am using this script since February and I never had any problems with it.
But thanks for you message that can helps others facing this problem :)

[shannonfenn]

The answer may lie here:

var last_index = threads[i].getMessageCount()-1;
var len = threads[i].getMessageCount();

Logger.log(threads[i].getMessageCount())
Logger.log(len)
Logger.log(threads[i].getMessageCount() - 1)
Logger.log(last_index)

result:

[16-01-12 12:21:55:798 AEDT] 2.0
[16-01-12 12:21:55:799 AEDT] 1.0
[16-01-12 12:21:55:800 AEDT] 1.0
[16-01-12 12:21:55:800 AEDT] 0.0

This being my first experience in javascript I can hardly diagnose, but there seems to be some problems with the array length being interpreted as the wrong integer value in expressions, but being resolved correctly when storing into a variable. The issue also occurs for a thread of 3 messages where I get a blank email due to an attempt to access a non-existant 4th element.

[Ionshard]

Let me just rephrase that so I can collect like terms

Logger.log(threads[i].getMessageCount())
//[16-01-12 12:21:55:798 AEDT] 2.0

var len = threads[i].getMessageCount();
Logger.log(len)
//[16-01-12 12:21:55:799 AEDT] 1.0

Logger.log(threads[i].getMessageCount() - 1)
//[16-01-12 12:21:55:800 AEDT] 1.0

var last_index = threads[i].getMessageCount()-1;
Logger.log(last_index)
//[16-01-12 12:21:55:800 AEDT] 0.0

Wow! This is every programmer's worst nightmare. A statement that evaluates to a different value if it's stored in a variable. Maybe this is some kind of rounding issue behind the scenes?

[shannonfenn]

You're likely correct, the lack of a built in integral type and weird array issues in general are worrying. Nonetheless your original proposed solution has worked for me with single and multi-message threads.