mcaxl/tests/test_wildcard.py

"""Tests for CUCM dial-plan wildcard pattern matching."""

import pytest

from mcaxl.route_plan import _pattern_matches_number, _wildcard_to_regex


class TestLiteralPatterns:
    def test_exact_match(self):
        assert _pattern_matches_number("1001", "1001")

    def test_no_match(self):
        assert not _pattern_matches_number("1001", "1002")

    def test_escaped_plus(self):
        assert _pattern_matches_number(r"\+15551234567", "+15551234567")
        assert not _pattern_matches_number(r"\+15551234567", "15551234567")


class TestXWildcard:
    def test_X_matches_any_digit(self):
        assert _pattern_matches_number("XXXX", "1234")
        assert _pattern_matches_number("XXXX", "9999")

    def test_X_only_matches_digits(self):
        assert not _pattern_matches_number("XXXX", "abc1")
        assert not _pattern_matches_number("XXXX", "12")  # too short
        assert not _pattern_matches_number("XXXX", "12345")  # too long

    def test_X_mixed_with_literal(self):
        assert _pattern_matches_number("9XXXX", "91234")
        assert not _pattern_matches_number("9XXXX", "81234")


class TestBangWildcard:
    def test_bang_matches_one_or_more(self):
        assert _pattern_matches_number("9!", "91")
        assert _pattern_matches_number("9!", "915551234567")

    def test_bang_requires_at_least_one(self):
        assert not _pattern_matches_number("9!", "9")


class TestCharacterClass:
    def test_class_matches_any_in_set(self):
        assert _pattern_matches_number("[2-9]XXX", "2000")
        assert _pattern_matches_number("[2-9]XXX", "9999")

    def test_class_excludes_outside_set(self):
        assert not _pattern_matches_number("[2-9]XXX", "1000")
        assert not _pattern_matches_number("[2-9]XXX", "0000")


class TestDotTerminator:
    def test_dot_is_zero_width(self):
        # CUCM's '.' is a marker for digit-discard, not a regex char
        assert _pattern_matches_number("9.911", "9911")
        assert _pattern_matches_number("10.911", "10911")

    def test_dot_with_X_after(self):
        assert _pattern_matches_number("9.[2-9]XXXXXXXXX", "92085551234")


class TestAtPattern:
    def test_at_matches_any_digits(self):
        # @ would normally apply a route filter; we treat it as "any digits"
        assert _pattern_matches_number("9.@", "915551234567")
        assert _pattern_matches_number("\\+.@", "+15551234567")


class TestEdgeCases:
    def test_invalid_regex_returns_false(self):
        # An unbalanced bracket should not raise
        result = _pattern_matches_number("[", "1")
        assert result is False

    def test_empty_pattern(self):
        assert _pattern_matches_number("", "")
        assert not _pattern_matches_number("", "1")

    def test_regex_anchors(self):
        # Make sure we don't match a substring
        assert not _pattern_matches_number("911", "1911")
        assert not _pattern_matches_number("911", "9111")


class TestRegexConversion:
    def test_X_to_digit_class(self):
        # Bounded after Hamilton MAJOR #4 — `X` still matches a single digit
        assert _wildcard_to_regex("X") == r"^\d$"

    def test_bang_to_bounded_digits(self):
        # Bounded after Hamilton MAJOR #4 — was \d+, now \d{1,N}.
        # Adjacent !!! used to compile to (\d+)(\d+)(\d+) which has
        # exponential backtracking on near-miss inputs.
        regex = _wildcard_to_regex("!")
        # Must be anchored, must contain a digit class with an upper bound.
        assert regex.startswith("^") and regex.endswith("$")
        assert r"\d{1," in regex, (
            f"`!` must compile to bounded `\\d{{1,N}}` to prevent "
            f"catastrophic backtracking; got: {regex}"
        )

    def test_anchored(self):
        regex = _wildcard_to_regex("9XXX")
        assert regex.startswith("^")
        assert regex.endswith("$")


class TestUnclosedBracketIsExplicitError:
    """Hamilton review MAJOR #4 (part 2): unclosed `[` used to silently
    fall back to treating the bracket as a literal. That produced wrong
    matches with no warning. Fix: surface the malformed pattern as an
    explicit error so the caller can flag it.
    """

    def test_unclosed_bracket_raises(self):
        import pytest as _pytest
        with _pytest.raises(ValueError, match="bracket"):
            _wildcard_to_regex("[0-9")

    def test_unclosed_bracket_in_pattern_match_returns_false(self):
        # _pattern_matches_number must catch the ValueError from the
        # malformed pattern and return False (so a single bad pattern
        # doesn't crash translation_chain).
        assert _pattern_matches_number("[0-9", "1") is False

    def test_well_formed_bracket_still_works(self):
        # Sanity: the fix shouldn't break legitimate character classes
        assert _pattern_matches_number("[2-9]XX", "456")
        assert not _pattern_matches_number("[2-9]XX", "156")


class TestRegexBacktrackingBound:
    """Hamilton review MAJOR #4 (part 1): adjacent `!` wildcards used to
    compile to `\\d+\\d+\\d+...` which is exponentially slow on near-miss
    input. Bounded `\\d{1,N}` keeps it polynomial.
    """

    def test_pathological_pattern_completes_quickly(self):
        # 10 adjacent `!` matched against a long near-miss number.
        # Pre-fix this could take seconds; bounded should finish in ms.
        import time
        pat = "!" * 10
        # 30 digits + a trailing letter — guarantees no full match
        num = "1" * 30 + "X"
        t0 = time.monotonic()
        result = _pattern_matches_number(pat, num)
        elapsed = time.monotonic() - t0
        assert result is False
        assert elapsed < 0.5, (
            f"pathological `!` chain must finish quickly even on near-miss; "
            f"took {elapsed:.3f}s"
        )