from __future__ import annotations

from agent_platform.text import truncate_middle


def test_truncate_middle_preserves_error_at_end() -> None:
    text = "stdout:" + ("x" * 1000) + "\nNameError: start is not defined"

    truncated = truncate_middle(text, 120)

    assert len(truncated) == 120
    assert truncated.startswith("stdout:")
    assert "middle omitted" in truncated
    assert truncated.endswith("NameError: start is not defined")


def test_truncate_middle_leaves_short_text_unchanged() -> None:
    assert truncate_middle("short", 20) == "short"


def test_truncate_middle_honors_tiny_limits() -> None:
    marker = "<omitted>"

    assert truncate_middle("abcdef", 0, marker) == ""
    assert truncate_middle("abcdef", 3, marker) == "abc"
    assert truncate_middle("abcdefghijklmnopqrstuvwxyz", len(marker) + 1, marker) == "a<omitted>"