test_callbacks.py revision 12037:d28054ac6ec9 
1import pytest
2
3
4def test_callbacks():
5    from functools import partial
6    from pybind11_tests import (test_callback1, test_callback2, test_callback3,
7                                test_callback4, test_callback5)
8
9    def func1():
10        return "func1"
11
12    def func2(a, b, c, d):
13        return "func2", a, b, c, d
14
15    def func3(a):
16        return "func3({})".format(a)
17
18    assert test_callback1(func1) == "func1"
19    assert test_callback2(func2) == ("func2", "Hello", "x", True, 5)
20    assert test_callback1(partial(func2, 1, 2, 3, 4)) == ("func2", 1, 2, 3, 4)
21    assert test_callback1(partial(func3, "partial")) == "func3(partial)"
22    assert test_callback3(lambda i: i + 1) == "func(43) = 44"
23
24    f = test_callback4()
25    assert f(43) == 44
26    f = test_callback5()
27    assert f(number=43) == 44
28
29
30def test_keyword_args_and_generalized_unpacking():
31    from pybind11_tests import (test_tuple_unpacking, test_dict_unpacking, test_keyword_args,
32                                test_unpacking_and_keywords1, test_unpacking_and_keywords2,
33                                test_unpacking_error1, test_unpacking_error2,
34                                test_arg_conversion_error1, test_arg_conversion_error2)
35
36    def f(*args, **kwargs):
37        return args, kwargs
38
39    assert test_tuple_unpacking(f) == (("positional", 1, 2, 3, 4, 5, 6), {})
40    assert test_dict_unpacking(f) == (("positional", 1), {"key": "value", "a": 1, "b": 2})
41    assert test_keyword_args(f) == ((), {"x": 10, "y": 20})
42    assert test_unpacking_and_keywords1(f) == ((1, 2), {"c": 3, "d": 4})
43    assert test_unpacking_and_keywords2(f) == (
44        ("positional", 1, 2, 3, 4, 5),
45        {"key": "value", "a": 1, "b": 2, "c": 3, "d": 4, "e": 5}
46    )
47
48    with pytest.raises(TypeError) as excinfo:
49        test_unpacking_error1(f)
50    assert "Got multiple values for keyword argument" in str(excinfo.value)
51
52    with pytest.raises(TypeError) as excinfo:
53        test_unpacking_error2(f)
54    assert "Got multiple values for keyword argument" in str(excinfo.value)
55
56    with pytest.raises(RuntimeError) as excinfo:
57        test_arg_conversion_error1(f)
58    assert "Unable to convert call argument" in str(excinfo.value)
59
60    with pytest.raises(RuntimeError) as excinfo:
61        test_arg_conversion_error2(f)
62    assert "Unable to convert call argument" in str(excinfo.value)
63
64
65def test_lambda_closure_cleanup():
66    from pybind11_tests import test_cleanup, payload_cstats
67
68    test_cleanup()
69    cstats = payload_cstats()
70    assert cstats.alive() == 0
71    assert cstats.copy_constructions == 1
72    assert cstats.move_constructions >= 1
73
74
75def test_cpp_function_roundtrip():
76    """Test if passing a function pointer from C++ -> Python -> C++ yields the original pointer"""
77    from pybind11_tests import dummy_function, dummy_function2, test_dummy_function, roundtrip
78
79    assert test_dummy_function(dummy_function) == "matches dummy_function: eval(1) = 2"
80    assert test_dummy_function(roundtrip(dummy_function)) == "matches dummy_function: eval(1) = 2"
81    assert roundtrip(None, expect_none=True) is None
82    assert test_dummy_function(lambda x: x + 2) == "can't convert to function pointer: eval(1) = 3"
83
84    with pytest.raises(TypeError) as excinfo:
85        test_dummy_function(dummy_function2)
86    assert "incompatible function arguments" in str(excinfo.value)
87
88    with pytest.raises(TypeError) as excinfo:
89        test_dummy_function(lambda x, y: x + y)
90    assert any(s in str(excinfo.value) for s in ("missing 1 required positional argument",
91                                                 "takes exactly 2 arguments"))
92
93
94def test_function_signatures(doc):
95    from pybind11_tests import test_callback3, test_callback4
96
97    assert doc(test_callback3) == "test_callback3(arg0: Callable[[int], int]) -> str"
98    assert doc(test_callback4) == "test_callback4() -> Callable[[int], int]"
99
100
101def test_movable_object():
102    from pybind11_tests import callback_with_movable
103
104    assert callback_with_movable(lambda _: None) is True
105