ext/pybind11/tests/test_callbacks.py

   1 import pytest
   2 from pybind11_tests import callbacks as m
   3
   4
   5 def test_callbacks():
   6     from functools import partial
   7
   8     def func1():
   9         return "func1"
  10
  11     def func2(a, b, c, d):
  12         return "func2", a, b, c, d
  13
  14     def func3(a):
  15         return "func3({})".format(a)
  16
  17     assert m.test_callback1(func1) == "func1"
  18     assert m.test_callback2(func2) == ("func2", "Hello", "x", True, 5)
  19     assert m.test_callback1(partial(func2, 1, 2, 3, 4)) == ("func2", 1, 2, 3, 4)
  20     assert m.test_callback1(partial(func3, "partial")) == "func3(partial)"
  21     assert m.test_callback3(lambda i: i + 1) == "func(43) = 44"
  22
  23     f = m.test_callback4()
  24     assert f(43) == 44
  25     f = m.test_callback5()
  26     assert f(number=43) == 44
  27
  28
  29 def test_bound_method_callback():
  30     # Bound Python method:
  31     class MyClass:
  32         def double(self, val):
  33             return 2 * val
  34
  35     z = MyClass()
  36     assert m.test_callback3(z.double) == "func(43) = 86"
  37
  38     z = m.CppBoundMethodTest()
  39     assert m.test_callback3(z.triple) == "func(43) = 129"
  40
  41
  42 def test_keyword_args_and_generalized_unpacking():
  43
  44     def f(*args, **kwargs):
  45         return args, kwargs
  46
  47     assert m.test_tuple_unpacking(f) == (("positional", 1, 2, 3, 4, 5, 6), {})
  48     assert m.test_dict_unpacking(f) == (("positional", 1), {"key": "value", "a": 1, "b": 2})
  49     assert m.test_keyword_args(f) == ((), {"x": 10, "y": 20})
  50     assert m.test_unpacking_and_keywords1(f) == ((1, 2), {"c": 3, "d": 4})
  51     assert m.test_unpacking_and_keywords2(f) == (
  52         ("positional", 1, 2, 3, 4, 5),
  53         {"key": "value", "a": 1, "b": 2, "c": 3, "d": 4, "e": 5}
  54     )
  55
  56     with pytest.raises(TypeError) as excinfo:
  57         m.test_unpacking_error1(f)
  58     assert "Got multiple values for keyword argument" in str(excinfo.value)
  59
  60     with pytest.raises(TypeError) as excinfo:
  61         m.test_unpacking_error2(f)
  62     assert "Got multiple values for keyword argument" in str(excinfo.value)
  63
  64     with pytest.raises(RuntimeError) as excinfo:
  65         m.test_arg_conversion_error1(f)
  66     assert "Unable to convert call argument" in str(excinfo.value)
  67
  68     with pytest.raises(RuntimeError) as excinfo:
  69         m.test_arg_conversion_error2(f)
  70     assert "Unable to convert call argument" in str(excinfo.value)
  71
  72
  73 def test_lambda_closure_cleanup():
  74     m.test_cleanup()
  75     cstats = m.payload_cstats()
  76     assert cstats.alive() == 0
  77     assert cstats.copy_constructions == 1
  78     assert cstats.move_constructions >= 1
  79
  80
  81 def test_cpp_function_roundtrip():
  82     """Test if passing a function pointer from C++ -> Python -> C++ yields the original pointer"""
  83
  84     assert m.test_dummy_function(m.dummy_function) == "matches dummy_function: eval(1) = 2"
  85     assert (m.test_dummy_function(m.roundtrip(m.dummy_function)) ==
  86             "matches dummy_function: eval(1) = 2")
  87     assert m.roundtrip(None, expect_none=True) is None
  88     assert (m.test_dummy_function(lambda x: x + 2) ==
  89             "can't convert to function pointer: eval(1) = 3")
  90
  91     with pytest.raises(TypeError) as excinfo:
  92         m.test_dummy_function(m.dummy_function2)
  93     assert "incompatible function arguments" in str(excinfo.value)
  94
  95     with pytest.raises(TypeError) as excinfo:
  96         m.test_dummy_function(lambda x, y: x + y)
  97     assert any(s in str(excinfo.value) for s in ("missing 1 required positional argument",
  98                                                  "takes exactly 2 arguments"))
  99
 100
 101 def test_function_signatures(doc):
 102     assert doc(m.test_callback3) == "test_callback3(arg0: Callable[[int], int]) -> str"
 103     assert doc(m.test_callback4) == "test_callback4() -> Callable[[int], int]"
 104
 105
 106 def test_movable_object():
 107     assert m.callback_with_movable(lambda _: None) is True