Applescript script to open a new tab in iTerm if a window exists, otherwise to open a new window. Useful with Hammerspoon.

iterm_tab.scpt

tell application "iTerm"
    activate
    -- Check if iTerm is running and has at least one window
    if (count of windows) is greater than 0 then
        -- iTerm is running and has at least one window, so create a new tab
        tell current window
            create tab with default profile
        end tell
    else
        -- iTerm is running but has no windows, so create a new window
        create window with default profile
    end if
end tell