Files
pytest2/testing/test_mark_expression.py
Ran Benita a718ad6363 Stop using Python's eval() for -m and -k
Previously, the expressions given to the `-m` and `-k` options were
evaluated with `eval`. This causes a few issues:

- Python keywords cannot be used.

- Constants like numbers, None, True, False are not handled correctly.

- Various syntax like numeric operators and `X if Y else Z` is supported
  unintentionally.

- `eval()` is somewhat dangerous for arbitrary input.

- Can fail in many ways so requires `except Exception`.

The format we want to support is quite simple, so change to a custom
parser. This fixes the issues above, and gives us full control of the
format, so can be documented comprehensively and even be extended in the
future if we wish.
2020-05-01 12:59:06 +03:00

163 lines
4.4 KiB
Python

import pytest
from _pytest.mark.expression import evaluate
from _pytest.mark.expression import ParseError
def test_empty_is_false() -> None:
assert not evaluate("", lambda ident: False)
assert not evaluate("", lambda ident: True)
assert not evaluate(" ", lambda ident: False)
assert not evaluate("\t", lambda ident: False)
@pytest.mark.parametrize(
("expr", "expected"),
(
("true", True),
("true", True),
("false", False),
("not true", False),
("not false", True),
("not not true", True),
("not not false", False),
("true and true", True),
("true and false", False),
("false and true", False),
("true and true and true", True),
("true and true and false", False),
("true and true and not true", False),
("false or false", False),
("false or true", True),
("true or true", True),
("true or true or false", True),
("true and true or false", True),
("not true or true", True),
("(not true) or true", True),
("not (true or true)", False),
("true and true or false and false", True),
("true and (true or false) and false", False),
("true and (true or (not (not false))) and false", False),
),
)
def test_basic(expr: str, expected: bool) -> None:
matcher = {"true": True, "false": False}.__getitem__
assert evaluate(expr, matcher) is expected
@pytest.mark.parametrize(
("expr", "expected"),
(
(" true ", True),
(" ((((((true)))))) ", True),
(" ( ((\t (((true))))) \t \t)", True),
("( true and (((false))))", False),
("not not not not true", True),
("not not not not not true", False),
),
)
def test_syntax_oddeties(expr: str, expected: bool) -> None:
matcher = {"true": True, "false": False}.__getitem__
assert evaluate(expr, matcher) is expected
@pytest.mark.parametrize(
("expr", "column", "message"),
(
("(", 2, "expected not OR left parenthesis OR identifier; got end of input"),
(" (", 3, "expected not OR left parenthesis OR identifier; got end of input",),
(
")",
1,
"expected not OR left parenthesis OR identifier; got right parenthesis",
),
(
") ",
1,
"expected not OR left parenthesis OR identifier; got right parenthesis",
),
("not", 4, "expected not OR left parenthesis OR identifier; got end of input",),
(
"not not",
8,
"expected not OR left parenthesis OR identifier; got end of input",
),
(
"(not)",
5,
"expected not OR left parenthesis OR identifier; got right parenthesis",
),
("and", 1, "expected not OR left parenthesis OR identifier; got and"),
(
"ident and",
10,
"expected not OR left parenthesis OR identifier; got end of input",
),
("ident and or", 11, "expected not OR left parenthesis OR identifier; got or",),
("ident ident", 7, "expected end of input; got identifier"),
),
)
def test_syntax_errors(expr: str, column: int, message: str) -> None:
with pytest.raises(ParseError) as excinfo:
evaluate(expr, lambda ident: True)
assert excinfo.value.column == column
assert excinfo.value.message == message
@pytest.mark.parametrize(
"ident",
(
".",
"...",
":::",
"a:::c",
"a+-b",
"אבגד",
"aaאבגדcc",
"a[bcd]",
"1234",
"1234abcd",
"1234and",
"notandor",
"not_and_or",
"not[and]or",
"1234+5678",
"123.232",
"True",
"False",
"if",
"else",
"while",
),
)
def test_valid_idents(ident: str) -> None:
assert evaluate(ident, {ident: True}.__getitem__)
@pytest.mark.parametrize(
"ident",
(
"/",
"\\",
"^",
"*",
"=",
"&",
"%",
"$",
"#",
"@",
"!",
"~",
"{",
"}",
'"',
"'",
"|",
";",
"",
),
)
def test_invalid_idents(ident: str) -> None:
with pytest.raises(ParseError):
evaluate(ident, lambda ident: True)