"""
Unit tests for pure utility functions — no database or network required.
"""
import pytest
from scribe.routes.export import _safe_filename


class TestSafeFilename:
    def test_normal_title(self):
        assert _safe_filename("My Note") == "My_Note"

    def test_strips_special_chars(self):
        result = _safe_filename("Hello: World! (2024)")
        assert ":" not in result
        assert "!" not in result
        assert "(" not in result

    def test_empty_title(self):
        assert _safe_filename("") == "untitled"

    def test_none_title(self):
        assert _safe_filename(None) == "untitled"

    def test_truncates_long_title(self):
        long = "a" * 100
        assert len(_safe_filename(long)) <= 80

    def test_preserves_hyphens(self):
        assert "-" in _safe_filename("my-note-title")

    def test_collapses_whitespace(self):
        result = _safe_filename("hello   world")
        assert "   " not in result
