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
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
//! A collection of useful macros for testing futures and tokio based code

/// Asserts a `Poll` is ready, returning the value.
///
/// This will invoke `panic!` if the provided `Poll` does not evaluate to `Poll::Ready` at
/// runtime.
///
/// # Custom Messages
///
/// This macro has a second form, where a custom panic message can be provided with or without
/// arguments for formatting.
///
/// # Examples
///
/// ```
/// use futures_util::future;
/// use tokio_test::{assert_ready, task};
///
/// let mut fut = task::spawn(future::ready(()));
/// assert_ready!(fut.poll());
/// ```
#[macro_export]
macro_rules! assert_ready {
    ($e:expr) => {{
        use core::task::Poll;
        match $e {
            Poll::Ready(v) => v,
            Poll::Pending => panic!("pending"),
        }
    }};
    ($e:expr, $($msg:tt)+) => {{
        use core::task::Poll;
        match $e {
            Poll::Ready(v) => v,
            Poll::Pending => {
                panic!("pending; {}", format_args!($($msg)+))
            }
        }
    }};
}

/// Asserts a `Poll<Result<...>>` is ready and `Ok`, returning the value.
///
/// This will invoke `panic!` if the provided `Poll` does not evaluate to `Poll::Ready(Ok(..))` at
/// runtime.
///
/// # Custom Messages
///
/// This macro has a second form, where a custom panic message can be provided with or without
/// arguments for formatting.
///
/// # Examples
///
/// ```
/// use futures_util::future;
/// use tokio_test::{assert_ready_ok, task};
///
/// let mut fut = task::spawn(future::ok::<_, ()>(()));
/// assert_ready_ok!(fut.poll());
/// ```
#[macro_export]
macro_rules! assert_ready_ok {
    ($e:expr) => {{
        use tokio_test::{assert_ready, assert_ok};
        let val = assert_ready!($e);
        assert_ok!(val)
    }};
    ($e:expr, $($msg:tt)+) => {{
        use tokio_test::{assert_ready, assert_ok};
        let val = assert_ready!($e, $($msg)*);
        assert_ok!(val, $($msg)*)
    }};
}

/// Asserts a `Poll<Result<...>>` is ready and `Err`, returning the error.
///
/// This will invoke `panic!` if the provided `Poll` does not evaluate to `Poll::Ready(Err(..))` at
/// runtime.
///
/// # Custom Messages
///
/// This macro has a second form, where a custom panic message can be provided with or without
/// arguments for formatting.
///
/// # Examples
///
/// ```
/// use futures_util::future;
/// use tokio_test::{assert_ready_err, task};
///
/// let mut fut = task::spawn(future::err::<(), _>(()));
/// assert_ready_err!(fut.poll());
/// ```
#[macro_export]
macro_rules! assert_ready_err {
    ($e:expr) => {{
        use tokio_test::{assert_ready, assert_err};
        let val = assert_ready!($e);
        assert_err!(val)
    }};
    ($e:expr, $($msg:tt)+) => {{
        use tokio_test::{assert_ready, assert_err};
        let val = assert_ready!($e, $($msg)*);
        assert_err!(val, $($msg)*)
    }};
}

/// Asserts a `Poll` is pending.
///
/// This will invoke `panic!` if the provided `Poll` does not evaluate to `Poll::Pending` at
/// runtime.
///
/// # Custom Messages
///
/// This macro has a second form, where a custom panic message can be provided with or without
/// arguments for formatting.
///
/// # Examples
///
/// ```
/// use futures_util::future;
/// use tokio_test::{assert_pending, task};
///
/// let mut fut = task::spawn(future::pending::<()>());
/// assert_pending!(fut.poll());
/// ```
#[macro_export]
macro_rules! assert_pending {
    ($e:expr) => {{
        use core::task::Poll;
        match $e {
            Poll::Pending => {}
            Poll::Ready(v) => panic!("ready; value = {:?}", v),
        }
    }};
    ($e:expr, $($msg:tt)+) => {{
        use core::task::Poll;
        match $e {
            Poll::Pending => {}
            Poll::Ready(v) => {
                panic!("ready; value = {:?}; {}", v, format_args!($($msg)+))
            }
        }
    }};
}

/// Asserts if a poll is ready and check for equality on the value
///
/// This will invoke `panic!` if the provided `Poll` does not evaluate to `Poll::Ready` at
/// runtime and the value produced does not partially equal the expected value.
///
/// # Custom Messages
///
/// This macro has a second form, where a custom panic message can be provided with or without
/// arguments for formatting.
///
/// # Examples
///
/// ```
/// use futures_util::future;
/// use tokio_test::{assert_ready_eq, task};
///
/// let mut fut = task::spawn(future::ready(42));
/// assert_ready_eq!(fut.poll(), 42);
/// ```
#[macro_export]
macro_rules! assert_ready_eq {
    ($e:expr, $expect:expr) => {
        let val = $crate::assert_ready!($e);
        assert_eq!(val, $expect)
    };

    ($e:expr, $expect:expr, $($msg:tt)+) => {
        let val = $crate::assert_ready!($e, $($msg)*);
        assert_eq!(val, $expect, $($msg)*)
    };
}

/// Asserts that the expression evaluates to `Ok` and returns the value.
///
/// This will invoke the `panic!` macro if the provided expression does not evaluate to `Ok` at
/// runtime.
///
/// # Custom Messages
///
/// This macro has a second form, where a custom panic message can be provided with or without
/// arguments for formatting.
///
/// # Examples
///
/// ```
/// use tokio_test::assert_ok;
///
/// let n: u32 = assert_ok!("123".parse());
///
/// let s = "123";
/// let n: u32 = assert_ok!(s.parse(), "testing parsing {:?} as a u32", s);
/// ```
#[macro_export]
macro_rules! assert_ok {
    ($e:expr) => {
        assert_ok!($e,)
    };
    ($e:expr,) => {{
        use std::result::Result::*;
        match $e {
            Ok(v) => v,
            Err(e) => panic!("assertion failed: Err({:?})", e),
        }
    }};
    ($e:expr, $($arg:tt)+) => {{
        use std::result::Result::*;
        match $e {
            Ok(v) => v,
            Err(e) => panic!("assertion failed: Err({:?}): {}", e, format_args!($($arg)+)),
        }
    }};
}

/// Asserts that the expression evaluates to `Err` and returns the error.
///
/// This will invoke the `panic!` macro if the provided expression does not evaluate to `Err` at
/// runtime.
///
/// # Custom Messages
///
/// This macro has a second form, where a custom panic message can be provided with or without
/// arguments for formatting.
///
/// # Examples
///
/// ```
/// use tokio_test::assert_err;
/// use std::str::FromStr;
///
///
/// let err = assert_err!(u32::from_str("fail"));
///
/// let msg = "fail";
/// let err = assert_err!(u32::from_str(msg), "testing parsing {:?} as u32", msg);
/// ```
#[macro_export]
macro_rules! assert_err {
    ($e:expr) => {
        assert_err!($e,);
    };
    ($e:expr,) => {{
        use std::result::Result::*;
        match $e {
            Ok(v) => panic!("assertion failed: Ok({:?})", v),
            Err(e) => e,
        }
    }};
    ($e:expr, $($arg:tt)+) => {{
        use std::result::Result::*;
        match $e {
            Ok(v) => panic!("assertion failed: Ok({:?}): {}", v, format_args!($($arg)+)),
            Err(e) => e,
        }
    }};
}

/// Asserts that an exact duration has elapsed since the start instant ±1ms.
///
/// ```rust
/// use tokio::time::{self, Instant};
/// use std::time::Duration;
/// use tokio_test::assert_elapsed;
/// # async fn test_time_passed() {
///
/// let start = Instant::now();
/// let dur = Duration::from_millis(50);
/// time::sleep(dur).await;
/// assert_elapsed!(start, dur);
/// # }
/// ```
///
/// This 1ms buffer is required because Tokio's hashed-wheel timer has finite time resolution and
/// will not always sleep for the exact interval.
#[macro_export]
macro_rules! assert_elapsed {
    ($start:expr, $dur:expr) => {{
        let elapsed = $start.elapsed();
        // type ascription improves compiler error when wrong type is passed
        let lower: std::time::Duration = $dur;

        // Handles ms rounding
        assert!(
            elapsed >= lower && elapsed <= lower + std::time::Duration::from_millis(1),
            "actual = {:?}, expected = {:?}",
            elapsed,
            lower
        );
    }};
}