Launch iTerm 2 with a predefined tab & split configuration using Apple's "Javascript for Automation"

iterm-launcher.js

/**
 * AppleScript to launch iterm2 terminals/tabs with configurable:
 * ~ Name <name>
 * ~ List of commands <cmds>
 * ~ Split behavior horizontal(h) or vertical(v) <split> :: (h, v)
 *
 * Run from terminal with `osascript iterm-launcher.js`.
 * Don't unfocus with the mouse/keyboard while executing the script.
 *
 * JS port of https://github.com/luismartingil/scripts/blob/master/iterm_launcher02.applescript
 */
var layout = [
  [{
    name: 'Pane 1',
    cmds: ['echo 1', 'ls'],
    split: 'v'
  }, {
    name: 'Pane 2',
    cmds: ['echo 2', 'ls']
  }],
  [{
    name: 'Pane A',
    cmds: ['echo A', 'ls'],
    split: 'h'
  }, {
    name: 'Pane B',
    cmds: ['echo B', 'ls']
  }]
];

/****************************************************************/

var SystemEvents = Application('System Events');
var iTerm = Application('iTerm');

// Returns the last pane that was created in iTerm
function lastPane() {
  var len = iTerm.currentTerminal.sessions.length;
  return iTerm.currentTerminal.sessions[len - 1];
}

for (var i = 0; i < layout.length; i++) {
  var tabItem = layout[i];

  // Create a new tab
  iTerm.currentTerminal.launch({session: i + ''});

  for (var j = 0; j < tabItem.length; j++) {
    var paneItem = tabItem[j];

    // Initialize a new pane
    var pane = lastPane();
    pane.name = paneItem.name;

    // Run the commands
    for (var k = 0; k < paneItem.cmds.length; k++) {
      pane.write({text: paneItem.cmds[k]});
    }

    // Execute the split
    if ('split' in paneItem) {
      var splitChar = 'd';
      if (paneItem.split == 'h') {
        splitChar = 'D';
      }
      SystemEvents.keystroke(splitChar, {using: 'command down'});
    }
  }
}

Thank you so much. Spent an hour trying to figure this out!