"""Tests for mutation rules."""

from app.dataset.rules.python.null_pointer import NoneReferenceRule
from app.dataset.rules.python.boundary_error import BoundaryErrorRule
from app.dataset.rules.python.logic_operator import LogicOperatorRule
from app.dataset.rules.registry import get_registry


def test_python_none_reference():
    src = """def process(data):
    if data is not None:
        x = data.upper()
        return x
"""
    m = NoneReferenceRule().detect_and_mutate(src)
    assert m is not None
    assert m.defect_type == "null_pointer"
    assert "if data is not None" not in m.mutated_source


def test_python_boundary_error():
    src = """def get(items, i):
    if i < len(items):
        return items[i]
"""
    m = BoundaryErrorRule().detect_and_mutate(src)
    assert m is not None
    assert "<=" in m.mutated_source


def test_python_logic_operator():
    src = """def ok(a, b):
    return a and b
"""
    m = LogicOperatorRule().detect_and_mutate(src)
    assert m is not None
    assert " or " in m.mutated_source


def test_registry_discovers_rules():
    registry = get_registry()
    assert "python" in registry.all_rules()
    assert "java" in registry.all_rules()
    assert "javascript" in registry.all_rules()