assertables/assert_fn_ok/
assert_fn_ok_eq.rs

1//! Assert a function Ok(…) is equal to another.
2//!
3//! Pseudocode:<br>
4//! (a_function(a_param) ⇒ Ok(a) ⇒ a) = (b_function(b_param) ⇒ Ok(b) ⇒ b)
5//!
6//! # Example
7//!
8//! ```rust
9//! use assertables::*;
10//! fn f(i: i8) -> Result<String, String> {
11//!     match i {
12//!         0..=9 => Ok(format!("{}", i)),
13//!         _ => Err(format!("{:?} is out of range", i)),
14//!     }
15//! }
16//!
17//! let a: i8 = 1;
18//! let b: i8 = 1;
19//! assert_fn_ok_eq!(f, a, f, b);
20//! ```
21//!
22//! # Module macros
23//!
24//! * [`assert_fn_ok_eq`](macro@crate::assert_fn_ok_eq)
25//! * [`assert_fn_ok_eq_as_result`](macro@crate::assert_fn_ok_eq_as_result)
26//! * [`debug_assert_fn_ok_eq`](macro@crate::debug_assert_fn_ok_eq)
27
28/// Assert a function Ok(…) is equal to another.
29///
30/// Pseudocode:<br>
31/// (a_function(a_param) ⇒ Ok(a) ⇒ a) = (b_function(b_param) ⇒ Ok(b) ⇒ b)
32///
33/// * If true, return Result `Ok(a, b)`.
34///
35/// * Otherwise, return Result `Err(message)`.
36///
37/// This macro is useful for runtime checks, such as checking parameters,
38/// or sanitizing inputs, or handling different results in different ways.
39///
40/// # Module macros
41///
42/// * [`assert_fn_ok_eq`](macro@crate::assert_fn_ok_eq)
43/// * [`assert_fn_ok_eq_as_result`](macro@crate::assert_fn_ok_eq_as_result)
44/// * [`debug_assert_fn_ok_eq`](macro@crate::debug_assert_fn_ok_eq)
45///
46#[macro_export]
47macro_rules! assert_fn_ok_eq_as_result {
48
49    //// Arity 1
50
51    ($a_function:path, $a_param:expr, $b_function:path, $b_param:expr $(,)?) => {
52        match (&$a_function, &$a_param, &$b_function, &$b_param) {
53            (_a_function, a_param, _b_function, b_param) => {
54                match (
55                    $a_function($a_param),
56                    $b_function($b_param)
57                ) {
58                    (Ok(a), Ok(b)) => {
59                        if a == b {
60                            Ok((a, b))
61                        } else {
62                            Err(
63                                format!(
64                                    concat!(
65                                        "assertion failed: `assert_fn_ok_eq!(a_function, a_param, b_function, b_param)`\n",
66                                        "https://docs.rs/assertables/9.6.0/assertables/macro.assert_fn_ok_eq.html\n",
67                                        " a_function label: `{}`,\n",
68                                        "    a_param label: `{}`,\n",
69                                        "    a_param debug: `{:?}`,\n",
70                                        " b_function label: `{}`,\n",
71                                        "    b_param label: `{}`,\n",
72                                        "    b_param debug: `{:?}`,\n",
73                                        "                a: `{:?}`,\n",
74                                        "                b: `{:?}`"
75                                    ),
76                                    stringify!($a_function),
77                                    stringify!($a_param),
78                                    a_param,
79                                    stringify!($b_function),
80                                    stringify!($b_param),
81                                    b_param,
82                                    a,
83                                    b
84                                )
85                            )
86                        }
87                    },
88                    (a, b) => {
89                        Err(
90                            format!(
91                                concat!(
92                                    "assertion failed: `assert_fn_ok_eq!(a_function, a_param, b_function, b_param)`\n",
93                                    "https://docs.rs/assertables/9.6.0/assertables/macro.assert_fn_ok_eq.html\n",
94                                    " a_function label: `{}`,\n",
95                                    "    a_param label: `{}`,\n",
96                                    "    a_param debug: `{:?}`,\n",
97                                    " b_function label: `{}`,\n",
98                                    "    b_param label: `{}`,\n",
99                                    "    b_param debug: `{:?}`,\n",
100                                    "                a: `{:?}`,\n",
101                                    "                b: `{:?}`"
102                                ),
103                                stringify!($a_function),
104                                stringify!($a_param),
105                                a_param,
106                                stringify!($b_function),
107                                stringify!($b_param),
108                                b_param,
109                                a,
110                                b
111                            )
112                        )
113                    }
114                }
115            }
116        }
117    };
118
119    //// Arity 0
120
121    ($a_function:path, $b_function:path) => {
122        match (
123            $a_function(),
124            $b_function()
125        ) {
126            (Ok(a), Ok(b)) => {
127                if a == b {
128                    Ok((a, b))
129                } else {
130                    Err(
131                        format!(
132                            concat!(
133                                "assertion failed: `assert_fn_ok_eq!(a_function, b_function)`\n",
134                                "https://docs.rs/assertables/9.6.0/assertables/macro.assert_fn_ok_eq.html\n",
135                                " a_function label: `{}`,\n",
136                                " b_function label: `{}`,\n",
137                                "                a: `{:?}`,\n",
138                                "                b: `{:?}`"
139                            ),
140                            stringify!($a_function),
141                            stringify!($b_function),
142                            a,
143                            b
144                        )
145                    )
146                }
147            },
148            (a, b) => {
149                Err(
150                    format!(
151                        concat!(
152                            "assertion failed: `assert_fn_ok_eq!(a_function, b_function)`\n",
153                            "https://docs.rs/assertables/9.6.0/assertables/macro.assert_fn_ok_eq.html\n",
154                            " a_function label: `{}`,\n",
155                            " b_function label: `{}`,\n",
156                            "                a: `{:?}`,\n",
157                            "                b: `{:?}`"
158                        ),
159                        stringify!($a_function),
160                        stringify!($b_function),
161                        a,
162                        b
163                    )
164                )
165            }
166        }
167    };
168
169}
170
171#[cfg(test)]
172mod test_assert_fn_ok_eq_as_result {
173    use std::sync::Once;
174
175    mod arity_1 {
176
177        fn f(i: i8) -> Result<i8, i8> {
178            return Ok(i);
179        }
180
181        fn g(i: i8) -> Result<i8, i8> {
182            return Ok(i);
183        }
184
185        #[test]
186        fn eq() {
187            let a: i8 = 1;
188            let b: i8 = 1;
189            let actual = assert_fn_ok_eq_as_result!(f, a, g, b);
190            assert_eq!(actual.unwrap(), (1, 1));
191        }
192
193        #[test]
194        fn ne() {
195            let a: i8 = 1;
196            let b: i8 = 2;
197            let actual = assert_fn_ok_eq_as_result!(f, a, g, b);
198            let message = concat!(
199                "assertion failed: `assert_fn_ok_eq!(a_function, a_param, b_function, b_param)`\n",
200                "https://docs.rs/assertables/9.6.0/assertables/macro.assert_fn_ok_eq.html\n",
201                " a_function label: `f`,\n",
202                "    a_param label: `a`,\n",
203                "    a_param debug: `1`,\n",
204                " b_function label: `g`,\n",
205                "    b_param label: `b`,\n",
206                "    b_param debug: `2`,\n",
207                "                a: `1`,\n",
208                "                b: `2`"
209            );
210            assert_eq!(actual.unwrap_err(), message);
211        }
212    }
213
214    mod arity_0 {
215
216        fn f() -> Result<i8, i8> {
217            return Ok(1);
218        }
219
220        fn g() -> Result<i8, i8> {
221            return Ok(2);
222        }
223
224        #[test]
225        fn eq() {
226            let actual = assert_fn_ok_eq_as_result!(f, f);
227            assert_eq!(actual.unwrap(), (1, 1));
228        }
229
230        #[test]
231        fn ne() {
232            let actual = assert_fn_ok_eq_as_result!(f, g);
233            let message = concat!(
234                "assertion failed: `assert_fn_ok_eq!(a_function, b_function)`\n",
235                "https://docs.rs/assertables/9.6.0/assertables/macro.assert_fn_ok_eq.html\n",
236                " a_function label: `f`,\n",
237                " b_function label: `g`,\n",
238                "                a: `1`,\n",
239                "                b: `2`"
240            );
241            assert_eq!(actual.unwrap_err(), message);
242        }
243    }
244}
245
246/// Assert a function Ok(…) is equal to another.
247///
248/// Pseudocode:<br>
249/// (a_function(a_param) ⇒ Ok(a) ⇒ a) = (b_function(b_param) ⇒ Ok(b) ⇒ b)
250///
251/// * If true, return `(a, b)`.
252///
253/// * Otherwise, call [`panic!`] with a message and the values of the
254///   expressions with their debug representations.
255///
256/// # Examples
257///
258/// ```rust
259/// use assertables::*;
260/// # use std::panic;
261/// fn f(i: i8) -> Result<String, String> {
262///     match i {
263///         0..=9 => Ok(format!("{}", i)),
264///         _ => Err(format!("{:?} is out of range", i)),
265///     }
266/// }
267///
268/// # fn main() {
269/// let a: i8 = 1;
270/// let b: i8 = 1;
271/// assert_fn_ok_eq!(f, a, f, b);
272///
273/// # let result = panic::catch_unwind(|| {
274/// // This will panic
275/// let a: i8 = 1;
276/// let b: i8 = 2;
277/// assert_fn_ok_eq!(f, a, f, b);
278/// # });
279/// // assertion failed: `assert_fn_ok_eq!(a_function, a_param, b_function, b_param)`
280/// // https://docs.rs/assertables/9.6.0/assertables/macro.assert_fn_ok_eq.html
281/// //  a_function label: `f`,
282/// //     a_param label: `a`,
283/// //     a_param debug: `1`,
284/// //  b_function label: `f`,
285/// //     b_param label: `b`,
286/// //     b_param debug: `2`,
287/// //                 a: `\"1\"`,
288/// //                 b: `\"2\"`
289/// # let actual = result.unwrap_err().downcast::<String>().unwrap().to_string();
290/// # let message = concat!(
291/// #     "assertion failed: `assert_fn_ok_eq!(a_function, a_param, b_function, b_param)`\n",
292/// #     "https://docs.rs/assertables/9.6.0/assertables/macro.assert_fn_ok_eq.html\n",
293/// #     " a_function label: `f`,\n",
294/// #     "    a_param label: `a`,\n",
295/// #     "    a_param debug: `1`,\n",
296/// #     " b_function label: `f`,\n",
297/// #     "    b_param label: `b`,\n",
298/// #     "    b_param debug: `2`,\n",
299/// #     "                a: `\"1\"`,\n",
300/// #     "                b: `\"2\"`"
301/// # );
302/// # assert_eq!(actual, message);
303/// # }
304/// ```
305///
306/// # Module macros
307///
308/// * [`assert_fn_ok_eq`](macro@crate::assert_fn_ok_eq)
309/// * [`assert_fn_ok_eq_as_result`](macro@crate::assert_fn_ok_eq_as_result)
310/// * [`debug_assert_fn_ok_eq`](macro@crate::debug_assert_fn_ok_eq)
311///
312#[macro_export]
313macro_rules! assert_fn_ok_eq {
314
315    //// Arity 1
316
317    ($a_function:path, $a_param:expr, $b_function:path, $b_param:expr $(,)?) => {
318        match $crate::assert_fn_ok_eq_as_result!($a_function, $a_param, $b_function, $b_param) {
319            Ok(x) => x,
320            Err(err) => panic!("{}", err),
321        }
322    };
323
324    ($a_function:path, $a_param:expr, $b_function:path, $b_param:expr, $($message:tt)+) => {
325        match $crate::assert_fn_ok_eq_as_result!($a_function, $a_param, $b_function, $b_param) {
326            Ok(x) => x,
327            Err(err) => panic!("{}\n{}", format_args!($($message)+), err),
328        }
329    };
330
331    //// Arity 0
332
333    ($a_function:path, $b_function:path) => {
334        match $crate::assert_fn_ok_eq_as_result!($a_function, $b_function) {
335            Ok(x) => x,
336            Err(err) => panic!("{}", err),
337        }
338    };
339
340    ($a_function:path, $b_function:path, $($message:tt)+) => {
341        match $crate::assert_fn_ok_eq_as_result!($a_function, $b_function) {
342            Ok(x) => x,
343            Err(err) => panic!("{}\n{}", format_args!($($message)+), err),
344        }
345    };
346}
347
348#[cfg(test)]
349mod test_assert_fn_ok_eq {
350    use std::panic;
351
352    mod arity_1 {
353        use super::*;
354
355        fn f(i: i8) -> Result<i8, i8> {
356            return Ok(i);
357        }
358
359        fn g(i: i8) -> Result<i8, i8> {
360            return Ok(i);
361        }
362
363        #[test]
364        fn eq() {
365            let a: i8 = 1;
366            let b: i8 = 1;
367            let actual = assert_fn_ok_eq!(f, a, g, b);
368            assert_eq!(actual, (1, 1));
369        }
370
371        #[test]
372        fn ne() {
373            let result = panic::catch_unwind(|| {
374                let a: i8 = 1;
375                let b: i8 = 2;
376                let _actual = assert_fn_ok_eq!(f, a, g, b);
377            });
378            let message = concat!(
379                "assertion failed: `assert_fn_ok_eq!(a_function, a_param, b_function, b_param)`\n",
380                "https://docs.rs/assertables/9.6.0/assertables/macro.assert_fn_ok_eq.html\n",
381                " a_function label: `f`,\n",
382                "    a_param label: `a`,\n",
383                "    a_param debug: `1`,\n",
384                " b_function label: `g`,\n",
385                "    b_param label: `b`,\n",
386                "    b_param debug: `2`,\n",
387                "                a: `1`,\n",
388                "                b: `2`"
389            );
390            assert_eq!(
391                result
392                    .unwrap_err()
393                    .downcast::<String>()
394                    .unwrap()
395                    .to_string(),
396                message
397            );
398        }
399    }
400
401    mod arity_0 {
402        use super::*;
403
404        fn f() -> Result<i8, i8> {
405            return Ok(1);
406        }
407
408        fn g() -> Result<i8, i8> {
409            return Ok(2);
410        }
411
412        #[test]
413        fn eq() {
414            let actual = assert_fn_ok_eq!(f, f);
415            assert_eq!(actual, (1, 1));
416        }
417
418        #[test]
419        fn ne() {
420            let result = panic::catch_unwind(|| {
421                let _actual = assert_fn_ok_eq!(f, g);
422            });
423            let message = concat!(
424                "assertion failed: `assert_fn_ok_eq!(a_function, b_function)`\n",
425                "https://docs.rs/assertables/9.6.0/assertables/macro.assert_fn_ok_eq.html\n",
426                " a_function label: `f`,\n",
427                " b_function label: `g`,\n",
428                "                a: `1`,\n",
429                "                b: `2`"
430            );
431            assert_eq!(
432                result
433                    .unwrap_err()
434                    .downcast::<String>()
435                    .unwrap()
436                    .to_string(),
437                message
438            );
439        }
440    }
441}
442
443/// Assert a function Ok(…) is equal to another.
444///
445/// Pseudocode:<br>
446/// (a_function(a_param) ⇒ Ok(a) ⇒ a) = (b_function(b_param) ⇒ Ok(b) ⇒ b)
447///
448/// This macro provides the same statements as [`assert_fn_ok_eq`](macro.assert_fn_ok_eq.html),
449/// except this macro's statements are only enabled in non-optimized
450/// builds by default. An optimized build will not execute this macro's
451/// statements unless `-C debug-assertions` is passed to the compiler.
452///
453/// This macro is useful for checks that are too expensive to be present
454/// in a release build but may be helpful during development.
455///
456/// The result of expanding this macro is always type checked.
457///
458/// An unchecked assertion allows a program in an inconsistent state to
459/// keep running, which might have unexpected consequences but does not
460/// introduce unsafety as long as this only happens in safe code. The
461/// performance cost of assertions, however, is not measurable in general.
462/// Replacing `assert*!` with `debug_assert*!` is thus only encouraged
463/// after thorough profiling, and more importantly, only in safe code!
464///
465/// This macro is intended to work in a similar way to
466/// [`::std::debug_assert`](https://doc.rust-lang.org/std/macro.debug_assert.html).
467///
468/// # Module macros
469///
470/// * [`assert_fn_ok_eq`](macro@crate::assert_fn_ok_eq)
471/// * [`assert_fn_ok_eq`](macro@crate::assert_fn_ok_eq)
472/// * [`debug_assert_fn_ok_eq`](macro@crate::debug_assert_fn_ok_eq)
473///
474#[macro_export]
475macro_rules! debug_assert_fn_ok_eq {
476    ($($arg:tt)*) => {
477        if $crate::cfg!(debug_assertions) {
478            $crate::assert_fn_ok_eq!($($arg)*);
479        }
480    };
481}