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|
import pytest
def test_match_sequence_string_bug():
x = "x"
match x:
case ['x']:
y = 2
case 'x':
y = 5
assert y == 5
def test_sequence_missing_not_used():
class defaultdict(dict):
def __missing__(self, key):
return 0
x = defaultdict()
x[1] = 1
match x:
case {0: 0}:
y = 0
case {**z}:
y = 1
assert x == {1: 1} # no keys added
assert y == 1 # second case applies
assert z == {1: 1} # the extracted inner dict is like the outer one
def test_error_name_bindings_duplicate():
with pytest.raises(SyntaxError) as info:
exec("""
match x:
case [a, a]:
pass
""")
def test_error_name_bindings_duplicate_or():
with pytest.raises(SyntaxError) as info:
exec("""
def f(x):
match x:
case [1 as a,
((2 as a) | (3 as a))]: return 17
""")
assert info.value.msg == "multiple assignments to name 'a' in pattern, previous one was on line 4"
assert info.value.lineno == 5
def test_error_name_bindings_or():
with pytest.raises(SyntaxError) as info:
exec("""
match x:
case "a" | a:
pass
""")
def test_error_allow_always_passing_or():
with pytest.raises(SyntaxError) as info:
exec("""
match x:
case a | "a":
pass
""")
assert info.value.msg == "name capture 'a' makes remaining patterns unreachable"
def test_error_forbidden_name():
with pytest.raises(SyntaxError) as info:
exec("""
match x:
case 1 as True:
pass
""")
def test_match_list():
def match_list(x):
match x:
case [True]: return "[True]"
case [1,2,3]: return "list[1,2,3]"
case [1]: return "list[1]"
case []: return "emptylist"
case [_]: return "list"
assert match_list(['']) == "list"
assert match_list([1]) == "list[1]"
assert match_list([1,2,3]) == "list[1,2,3]"
assert match_list([1,2,4]) is None
assert match_list([2,3,4]) is None
assert match_list([1, 2]) is None
assert match_list([]) == "emptylist"
def test_match_with_if_bug():
def match_truthy(x):
match x:
case a if a: return a
assert match_truthy(1) == 1
assert match_truthy(True) is True
assert match_truthy([]) is None
assert match_truthy('') is None
def test_or():
x = 2
match x:
case 1 | 2:
a = 2
case _:
a = 3
assert a == 2
def test_dont_use_is():
match [1.0]:
case [1]: pass
case _: assert False
def test_only_bind_at_end():
a = 5
match [1, 2, 3]:
case [a, 1, b]:
pass
assert a == 5
def test_or_reorder():
def or_orders(x):
match x:
case [a, b, 1] | [b, a, 2]:
return a, b
return 12
assert or_orders([1, 2, 1]) == (1, 2)
assert or_orders([1, 2, 2]) == (2, 1)
assert or_orders([1, 3, 4]) == 12
def test_bug_repeated_names_not_reset_between_cases():
def as_bug(x):
match x:
case 1 as y: return y
case 2 as y: return y
assert as_bug(1) == 1
assert as_bug(2) == 2
assert as_bug(3) is None
def test_bug_match_sequence_star():
def sequence_star_bug(x):
match x:
case [1, a, *rest, x, 3]:
return a, rest, x
assert sequence_star_bug([1, 2, 3, 4, 5, 6, 3]) == (2, [3, 4, 5], 6)
# rest must not end up in globals!
assert "rest" not in globals()
def test_bug_match_class_builtin():
def match_class_bool(x):
match x:
case bool(b) if b: return "True"
case bool(): return "False"
assert match_class_bool(True) == "True"
assert match_class_bool(False) == "False"
def test_error_repeated_class_keyword():
with pytest.raises(SyntaxError) as info:
exec("""
match x:
case A(a=_, a=_):
pass
""")
def test_error_duplicate_key():
with pytest.raises(SyntaxError) as info:
exec("""
match x:
case {"a": 1, "a": 2}:
pass
""")
assert info.value.msg == "mapping pattern checks duplicate key ('a')"
assert info.value.lineno == 3
def test_error_key_wrong_kind():
with pytest.raises(SyntaxError) as info:
exec("""
match x:
case {f"{a}": 1}:
pass
""")
assert info.value.msg == "mapping pattern keys may only match literals and attribute lookups"
assert info.value.lineno == 3
def test_error_key_wrong_kind():
with pytest.raises(SyntaxError) as info:
exec("""
match x:
case [a, *b, c, *d]:
pass
""")
assert info.value.msg == "multiple starred names in sequence pattern"
assert info.value.lineno == 3
def test_match_args_tuple():
class C:
__match_args__ = ["a", "b"]
a = 0
b = 1
x = C()
w = y = z = None
with pytest.raises(TypeError):
match x:
case C(y, z):
w = 12
assert w is y is z is None
def test_match_keys_duplicate_runtime():
class K:
k = "a"
w = y = z = None
with pytest.raises(ValueError):
match {"a": 1, "b": 2}:
case {K.k: y, "a": z}: w = 12
assert w is y is z is None
def test_optimize_unpack_sequence_star_no_capture():
class Sequence:
def __getitem__(self, index):
return index
def __len__(self):
return 42
def __iter__(self):
return self
def __next__(self):
return 1
a = 0
b = 0
match Sequence():
case [0, *_, b, 41]:
a = 1
assert a == 1
assert b == 40
def test_unpack_sequence_bug():
def f(w):
match w:
case (p, q) as x:
locals()
return p, q, x
assert f((1, 2)) == (1, 2, (1, 2))
assert "p" not in globals()
assert "q" not in globals()
def test_or_reordering_bug():
def annoying_or(x):
match x:
case ((a, b, c, d, e, 7) |
(a, b, d, e, c, 8)):
pass
out = locals()
del out["x"]
return out
res = annoying_or(range(3, 9))
exp = dict(a=3, b=4, d=5, e=6, c=7)
assert res == exp
def test_bytearray_does_not_match_sequence():
def sequence_match(x):
match x:
case [120]:
return 1
case 120:
return 2
return 3
assert sequence_match(bytearray(b"x")) == 3
def test_error_fstring():
with pytest.raises(SyntaxError) as info:
exec("""
def fstringbug():
match x:
case f"{x}":
pass
""")
assert info.value.msg == "patterns may only match literals and attribute lookups"
def test_collections_abcs():
import collections.abc
class Seq(collections.abc.Sequence):
__getitem__ = None
def __init__(self, l):
self.l = l
def __len__(self):
return self.l
match Seq(0):
case []:
y = 0
assert y == 0
match Seq(34):
case [*_]:
y = 10
assert y == 10
def test_sequence_doesnt_need_length():
class A:
def __getitem__(self, x):
return 1
match A():
case [*_]:
y = 10
assert y == 10
def test_collections_abc_mapping():
import collections.abc
class A:
pass
collections.abc.Mapping.register(A)
match A():
case [*_]: assert 0, "unreachable"
case {}: x = 11121
assert x == 11121
class B(A): # made after registering
pass
match B():
case [*_]: assert 0, "unreachable"
case {}: x = 111213434
assert x == 111213434
def test_abstract_isinstance_check():
class ABC(type):
def __instancecheck__(cls, inst):
"""Implement isinstance(inst, cls)."""
return any(cls.__subclasscheck__(c)
for c in set([type(inst), inst.__class__]))
def __subclasscheck__(cls, sub):
"""Implement issubclass(sub, cls)."""
candidates = cls.__dict__.get("__subclass__", set()) | set([cls])
return any(c in candidates for c in sub.mro())
class Integer(metaclass=ABC):
__subclass__ = set([int])
assert isinstance(12, Integer)
match 12:
case Integer(): pass
case _: assert 0 # unreachable
def test_dict_pattern_none_value_bug():
d = {"a": None}
res = 0
match d:
case {"a": None}:
res = 1
case _:
res = 2
assert res == 1
|
