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"""Snapshot suite for the compile-path edge-case fixtures.
Each fixture builds a small, intentionally-tricky pattern and pins the
emitted regex string. The fixtures are the ones most likely to silently
drift when the compile path is refactored: deeply nested alternation,
combined lookaround, item-4 named backreferences, and constructs that
:mod:`edify` flags for ReDoS.
"""
from collections.abc import Callable
from pathlib import Path
import pytest
from edify import Pattern, RegexBuilder
from edify.compile.redos import ReDoSWarning
from edify.testing import assert_snapshot
_SNAPSHOT_ROOT = Path(__file__).parent.parent / "snapshots" / "fixtures"
def _deeply_nested_alternation():
inner_alt = RegexBuilder().any_of("abc", "def", "ghi")
outer_alt = RegexBuilder().any_of("first", "second", "third")
return (
RegexBuilder()
.start_of_input()
.subexpression(inner_alt)
.string("-")
.subexpression(outer_alt)
.end_of_input()
)
def _combined_lookaround_positive_and_negative():
return (
RegexBuilder()
.assert_ahead()
.digit()
.end()
.assert_not_ahead()
.string("0")
.end()
.assert_behind()
.string("$")
.end()
.digit()
.digit()
.digit()
)
def _named_backreference_pair():
return (
RegexBuilder()
.named_capture("open")
.any_of("[", "(", "{")
.end()
.zero_or_more()
.word()
.named_back_reference("open")
)
def _nested_unbounded_quantifier_redos():
return RegexBuilder().one_or_more().group().one_or_more().digit().end()
def _alternation_with_overlapping_prefixes_redos():
return RegexBuilder().one_or_more().any_of("aa", "aaa", "aaaa")
def _hex_color_pattern():
return (
RegexBuilder()
.start_of_input()
.string("#")
.any_of_chars("0123456789abcdefABCDEF")
.exactly(6)
.word()
.end_of_input()
)
def _email_shape_pattern():
return (
RegexBuilder()
.start_of_input()
.one_or_more()
.any_of_chars("a-zA-Z0-9._%+-")
.string("@")
.one_or_more()
.any_of_chars("a-zA-Z0-9.-")
.string(".")
.at_least(2)
.letter()
.end_of_input()
)
def _pattern_composition_via_use():
reusable = Pattern().at_least(2).letter()
return RegexBuilder().start_of_input().subexpression(reusable).end_of_input()
_FIXTURES = [
("deeply_nested_alternation", _deeply_nested_alternation),
("combined_lookaround", _combined_lookaround_positive_and_negative),
("named_backreference_pair", _named_backreference_pair),
("nested_unbounded_quantifier_redos", _nested_unbounded_quantifier_redos),
("alternation_with_overlapping_prefixes_redos", _alternation_with_overlapping_prefixes_redos),
("hex_color_pattern", _hex_color_pattern),
("email_shape_pattern", _email_shape_pattern),
("pattern_composition_via_use", _pattern_composition_via_use),
]
@pytest.mark.parametrize(
("fixture_name", "builder_factory"), _FIXTURES, ids=[name for name, _ in _FIXTURES]
)
def test_edge_case_fixture_emits_the_snapshotted_regex(
fixture_name: str, builder_factory: Callable[[], RegexBuilder]
):
builder = builder_factory()
emitted = builder.to_regex_string()
snapshot_path = _SNAPSHOT_ROOT / f"{fixture_name}.regex"
assert_snapshot(emitted, snapshot_path)
def test_nested_unbounded_quantifier_fixture_raises_the_redos_warning():
with pytest.warns(ReDoSWarning):
_nested_unbounded_quantifier_redos().to_regex()
|
