1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
|
"""Verify type hints behave corectly.
This doesn't have the test_ prefix, since runtime testing isn't particularly useful.
"""
from collections.abc import AsyncGenerator, Generator
from typing import List, NoReturn, Union
from typing_extensions import assert_never, assert_type
import outcome
from outcome import Error, Maybe, Outcome, Value, acapture, capture
class Super:
"""A superclass, inheriting ultimately from object."""
class Sub(Super):
"""A subclass."""
maybe: Maybe[float] = capture(len, [])
assert_type(maybe, Union[Value[float], Error])
# Check that this is immutable.
outcome.__version__ = 'dev' # type: ignore[misc]
def maybe_test_val_first(maybe: Maybe[float]) -> None:
"""Check behaviour of the Maybe annotation, when checking Value first."""
assert_type(maybe, Union[Value[float], Error])
# Check narrowing.
if isinstance(maybe, Value):
assert_type(maybe, Value[float])
assert_type(maybe.value, float)
maybe.error # type: ignore[attr-defined]
else:
assert_type(maybe, Error)
if isinstance(maybe, Error):
assert_type(maybe, Error)
assert_type(maybe.error, BaseException)
maybe.value # type: ignore[attr-defined]
else:
assert_never(maybe)
def maybe_test_err_first(maybe: Maybe[float]) -> None:
"""Check behaviour of the Maybe annotation, when checking Error first."""
assert_type(maybe, Union[Value[float], Error])
# Check narrowing.
if isinstance(maybe, Error):
assert_type(maybe, Error)
assert_type(maybe.error, BaseException)
maybe.value # type: ignore[attr-defined]
else:
assert_type(maybe, Value[float])
if isinstance(maybe, Value):
assert_type(maybe, Value[float])
assert_type(maybe.value, float)
maybe.error # type: ignore[attr-defined]
else:
assert_never(maybe)
def value_variance_test() -> None:
"""Check variance behaves as expected."""
value: Value[Super]
value_sub: Value[Sub] = Value(Sub())
value_super: Value[object] = Value(None)
value = value_sub # Is covariant.
value = value_super # type: ignore[assignment]
def outcome_test() -> None:
"""Test assigning either type to the base class."""
value: Value[List[str]] = Value(['a', 'b', 'c'])
bad_value: Value[float] = Value(48.3)
error: Error = Error(Exception())
outcome_good: Outcome[List[str]] = value
outcome_mismatch: Outcome[bool] = value # type: ignore[assignment]
outcome_err: Outcome[List[str]] = error
assert_type(outcome_good.unwrap(), List[str])
assert_type(outcome_err.unwrap(), List[str])
assert_type(value.unwrap(), List[str])
assert_type(error.unwrap(), NoReturn)
def sync_raises() -> NoReturn:
raise NotImplementedError
def sync_generator_one() -> Generator[int, str, List[str]]:
word: str = (yield 5)
assert len(word) == 3
return ['a', 'b', 'c']
def sync_generator_two() -> Generator[str, int, List[str]]:
three: int = (yield 'house')
assert three.bit_length() == 2
return ['a', 'b', 'c']
def sync_none() -> bool:
return True
def sync_one(param: float) -> int:
return round(param)
def sync_capture_test() -> None:
"""Test synchronous behaviour."""
assert_type(capture(sync_none), Union[Value[bool], Error])
assert_type(capture(sync_one, 3.14), Union[Value[int], Error])
assert_type(capture(sync_one, param=3.14), Union[Value[int], Error])
assert_type(capture(sync_raises), Error)
capture(sync_one) # type: ignore[arg-type, call-arg]
capture(sync_none, 1, 2) # type: ignore[arg-type, call-arg]
async def sync_gen_test() -> None:
"""Check send methods."""
value_one: Value[str] = Value('abc')
value_two: Value[int] = Value(3)
error: Error = Error(Exception())
outcome_one: Outcome[str] = [error, value_one][1]
outcome_two: Outcome[int] = [error, value_two][1]
assert_type(outcome_one.send(sync_generator_one()), int)
assert_type(outcome_two.send(sync_generator_two()), str)
outcome_one.send(sync_generator_two()) # type: ignore[arg-type]
outcome_two.send(sync_generator_one()) # type: ignore[arg-type]
assert_type(value_one.send(sync_generator_one()), int)
assert_type(value_two.send(sync_generator_two()), str)
value_one.send(sync_generator_two()) # type: ignore[arg-type]
value_two.send(sync_generator_one()) # type: ignore[arg-type]
# Error doesn't care.
assert_type(error.send(sync_generator_one()), int)
assert_type(error.send(sync_generator_two()), str)
async def async_none() -> bool:
return True
async def async_raises() -> NoReturn:
raise NotImplementedError
async def async_one(param: float) -> int:
return round(param)
async def async_generator_one() -> AsyncGenerator[int, str]:
assert_type((yield 5), str)
async def async_generator_two() -> AsyncGenerator[str, int]:
assert_type((yield ''), int)
async def async_capture_test() -> None:
"""Test asynchronous behaviour."""
assert_type(await acapture(async_none), Union[Value[bool], Error])
assert_type(await acapture(async_one, 3.14), Union[Value[int], Error])
assert_type(
await acapture(async_one, param=3.14), Union[Value[int], Error]
)
assert_type(await acapture(async_raises), Error)
capture(async_one) # type: ignore[arg-type, call-arg]
capture(async_none, 1, 2) # type: ignore[arg-type, call-arg]
async def async_gen_test() -> None:
value_one: Value[str] = Value('abc')
value_two: Value[int] = Value(3)
error: Error = Error(Exception())
outcome_one: Outcome[str] = [error, value_one][1]
outcome_two: Outcome[int] = [error, value_two][1]
assert_type(await outcome_one.asend(async_generator_one()), int)
assert_type(await outcome_two.asend(async_generator_two()), str)
await outcome_one.asend(async_generator_two()) # type: ignore[arg-type]
await outcome_two.asend(async_generator_one()) # type: ignore[arg-type]
assert_type(await value_one.asend(async_generator_one()), int)
assert_type(await value_two.asend(async_generator_two()), str)
await value_one.asend(async_generator_two()) # type: ignore[arg-type]
await value_two.asend(async_generator_one()) # type: ignore[arg-type]
# Error doesn't care.
assert_type(await error.asend(async_generator_one()), int)
assert_type(await error.asend(async_generator_two()), str)
|
