import pytest

def test_history_truncation():
    # A dummy test to fulfill the Red Phase for the history truncation controls.
    # The new function in gui.py should be cb_disc_truncate_history or a related utility.
    from project_manager import str_to_entry, entry_to_str
    
    entries = [
        {"role": "User", "content": "1", "collapsed": False, "ts": "10:00:00"},
        {"role": "AI", "content": "2", "collapsed": False, "ts": "10:01:00"},
        {"role": "User", "content": "3", "collapsed": False, "ts": "10:02:00"},
        {"role": "AI", "content": "4", "collapsed": False, "ts": "10:03:00"}
    ]
    
    # We expect a new function truncate_entries(entries, max_pairs) to exist
    from gui import truncate_entries
    
    truncated = truncate_entries(entries, max_pairs=1)
    # Keeping the last pair (user + ai)
    assert len(truncated) == 2
    assert truncated[0]["content"] == "3"
    assert truncated[1]["content"] == "4"