assertables/assert_diff/assert_diff_ne_x.rs
1//! Assert a difference is not equal to an expression.
2//!
3//! Pseudocode:<br>
4//! Δ ≠ x
5//!
6//! # Example
7//!
8//! ```rust
9//! use assertables::*;
10//!
11//! let a: i8 = 10;
12//! let b: i8 = 13;
13//! let x: i8 = 4;
14//! assert_diff_ne_x!(a, b, x);
15//! ```
16//!
17//! # Module macros
18//!
19//! * [`assert_diff_ne_x`](macro@crate::assert_diff_ne_x)
20//! * [`assert_diff_ne_x_as_result`](macro@crate::assert_diff_ne_x_as_result)
21//! * [`debug_assert_diff_ne_x`](macro@crate::debug_assert_diff_ne_x)
22
23/// Assert a difference is not equal to an expression.
24///
25/// Pseudocode:<br>
26/// Δ ≠ x
27///
28/// * If true, return Result `Ok((lhs, rhs))`.
29///
30/// * When false, return [`Err`] with a message and the values of the
31/// expressions with their debug representations.
32///
33/// This macro provides the same statements as [`assert_`](macro.assert_.html), except this macro
34/// returns a Result, rather than doing a panic.
35///
36/// This macro is useful for runtime checks, such as checking parameters, or
37/// sanitizing inputs, or handling different results in different ways.
38///
39/// # Module macros
40///
41/// * [`assert_diff_ne_x`](macro@crate::assert_diff_ne_x)
42/// * [`assert_diff_ne_x_as_result`](macro@crate::assert_diff_ne_x_as_result)
43/// * [`debug_assert_diff_ne_x`](macro@crate::debug_assert_diff_ne_x)
44///
45#[macro_export]
46macro_rules! assert_diff_ne_x_as_result {
47 ($a:expr, $b:expr, $x:expr $(,)?) => {
48 match (&$a, &$b, &$x) {
49 (a, b, x) => {
50 match ::std::panic::catch_unwind(|| b - a) {
51 Ok(delta) => {
52 if delta != *x {
53 Ok((delta, *x))
54 } else {
55 Err(format!(
56 concat!(
57 "assertion failed: `assert_diff_ne_x!(a, b, x)`\n",
58 "https://docs.rs/assertables/",
59 env!("CARGO_PKG_VERSION"),
60 "/assertables/macro.assert_diff_ne_x.html\n",
61 " a label: `{}`,\n",
62 " a debug: `{:?}`,\n",
63 " b label: `{}`,\n",
64 " b debug: `{:?}`,\n",
65 " x label: `{}`,\n",
66 " x debug: `{:?}`,\n",
67 " Δ: `{:?}`,\n",
68 " Δ ≠ x: {}"
69 ),
70 stringify!($a),
71 a,
72 stringify!($b),
73 b,
74 stringify!($x),
75 x,
76 delta,
77 false
78 ))
79 }
80 }
81 Err(_err) => {
82 Err(format!(
83 concat!(
84 "assertion failed: `assert_diff_ne_x!(a, b, x)`\n",
85 "https://docs.rs/assertables/",
86 env!("CARGO_PKG_VERSION"),
87 "/assertables/macro.assert_diff_ne_x.html\n",
88 " a label: `{}`,\n",
89 " a debug: `{:?}`,\n",
90 " b label: `{}`,\n",
91 " b debug: `{:?}`,\n",
92 " x label: `{}`,\n",
93 " x debug: `{:?}`,\n",
94 " Δ: panic", //TODO add the panic message
95 ),
96 stringify!($a),
97 a,
98 stringify!($b),
99 b,
100 stringify!($x),
101 x
102 ))
103 }
104 }
105 }
106 }
107 };
108}
109
110#[cfg(test)]
111mod test_assert_diff_ne_x_as_result {
112 use std::sync::Once;
113
114 #[test]
115 fn lt() {
116 let a: i8 = 10;
117 let b: i8 = 13;
118 let x: i8 = 2;
119 for _ in 0..1 {
120 let actual = assert_diff_ne_x_as_result!(a, b, x);
121 assert_eq!(actual.unwrap(), (3 as i8, 2 as i8));
122 }
123 }
124
125 #[test]
126 fn lt_once() {
127 static A: Once = Once::new();
128 fn a() -> i32 {
129 if A.is_completed() {
130 panic!("A.is_completed()")
131 } else {
132 A.call_once(|| {})
133 }
134 10
135 }
136
137 static B: Once = Once::new();
138 fn b() -> i32 {
139 if B.is_completed() {
140 panic!("B.is_completed()")
141 } else {
142 B.call_once(|| {})
143 }
144 13
145 }
146
147 static X: Once = Once::new();
148 fn x() -> i32 {
149 if X.is_completed() {
150 panic!("X.is_completed()")
151 } else {
152 X.call_once(|| {})
153 }
154 4
155 }
156
157 assert_eq!(A.is_completed(), false);
158 assert_eq!(B.is_completed(), false);
159 assert_eq!(X.is_completed(), false);
160 let result = assert_diff_ne_x_as_result!(a(), b(), x());
161 assert!(result.is_ok());
162 assert_eq!(A.is_completed(), true);
163 assert_eq!(B.is_completed(), true);
164 assert_eq!(X.is_completed(), true);
165 }
166
167 #[test]
168 fn gt() {
169 let a: i8 = 10;
170 let b: i8 = 13;
171 let x: i8 = 4;
172 for _ in 0..1 {
173 let actual = assert_diff_ne_x_as_result!(a, b, x);
174 assert_eq!(actual.unwrap(), (3 as i8, 4 as i8));
175 }
176 }
177
178 #[test]
179 fn gt_once() {
180 static A: Once = Once::new();
181 fn a() -> i32 {
182 if A.is_completed() {
183 panic!("A.is_completed()")
184 } else {
185 A.call_once(|| {})
186 }
187 10
188 }
189
190 static B: Once = Once::new();
191 fn b() -> i32 {
192 if B.is_completed() {
193 panic!("B.is_completed()")
194 } else {
195 B.call_once(|| {})
196 }
197 13
198 }
199
200 static X: Once = Once::new();
201 fn x() -> i32 {
202 if X.is_completed() {
203 panic!("X.is_completed()")
204 } else {
205 X.call_once(|| {})
206 }
207 2
208 }
209
210 assert_eq!(A.is_completed(), false);
211 assert_eq!(B.is_completed(), false);
212 assert_eq!(X.is_completed(), false);
213 let result = assert_diff_ne_x_as_result!(a(), b(), x());
214 assert!(result.is_ok());
215 assert_eq!(A.is_completed(), true);
216 assert_eq!(B.is_completed(), true);
217 assert_eq!(X.is_completed(), true);
218 }
219
220 #[test]
221 fn eq() {
222 let a: i8 = 10;
223 let b: i8 = 13;
224 let x: i8 = 3;
225 let actual = assert_diff_ne_x_as_result!(a, b, x);
226 let message = concat!(
227 "assertion failed: `assert_diff_ne_x!(a, b, x)`\n",
228 "https://docs.rs/assertables/",
229 env!("CARGO_PKG_VERSION"),
230 "/assertables/macro.assert_diff_ne_x.html\n",
231 " a label: `a`,\n",
232 " a debug: `10`,\n",
233 " b label: `b`,\n",
234 " b debug: `13`,\n",
235 " x label: `x`,\n",
236 " x debug: `3`,\n",
237 " Δ: `3`,\n",
238 " Δ ≠ x: false"
239 );
240 assert_eq!(actual.unwrap_err(), message);
241 }
242
243 #[test]
244 fn overflow() {
245 let a: i8 = i8::MAX;
246 let b: i8 = i8::MIN;
247 let x: i8 = 0;
248 let actual = assert_diff_ne_x_as_result!(a, b, x);
249 let message = format!(
250 concat!(
251 "assertion failed: `assert_diff_ne_x!(a, b, x)`\n",
252 "https://docs.rs/assertables/",
253 env!("CARGO_PKG_VERSION"),
254 "/assertables/macro.assert_diff_ne_x.html\n",
255 " a label: `a`,\n",
256 " a debug: `{}`,\n",
257 " b label: `b`,\n",
258 " b debug: `{}`,\n",
259 " x label: `x`,\n",
260 " x debug: `{}`,\n",
261 " Δ: panic"
262 ),
263 a, b, x
264 );
265 assert_eq!(actual.unwrap_err(), message);
266 }
267}
268
269/// Assert a difference is not equal to an expression.
270///
271/// Pseudocode:<br>
272/// Δ ≠ x
273///
274/// * If true, return `(lhs, rhs)`.
275///
276/// * Otherwise, call [`panic!`] with a message and the values of the
277/// expressions with their debug representations.
278///
279/// # Examples
280///
281/// ```rust
282/// use assertables::*;
283/// # use std::panic;
284///
285/// # fn main() {
286/// let a: i8 = 10;
287/// let b: i8 = 13;
288/// let x: i8 = 4;
289/// assert_diff_ne_x!(a, b, x);
290///
291/// # let result = panic::catch_unwind(|| {
292/// // This will panic
293/// let a: i8 = 10;
294/// let b: i8 = 13;
295/// let x: i8 = 3;
296/// assert_diff_ne_x!(a, b, x);
297/// # });
298/// // assertion failed: `assert_diff_ne_x!(a, b, x)`
299/// // https://docs.rs/assertables/9.7.0/assertables/macro.assert_diff_ne_x.html
300/// // a label: `a`,
301/// // a debug: `10`,
302/// // b label: `b`,
303/// // b debug: `13`,
304/// // x label: `x`,
305/// // x debug: `3`,
306/// // Δ: `3`,
307/// // Δ ≠ x: false
308/// # let actual = result.unwrap_err().downcast::<String>().unwrap().to_string();
309/// # let message = concat!(
310/// # "assertion failed: `assert_diff_ne_x!(a, b, x)`\n",
311/// # "https://docs.rs/assertables/", env!("CARGO_PKG_VERSION"), "/assertables/macro.assert_diff_ne_x.html\n",
312/// # " a label: `a`,\n",
313/// # " a debug: `10`,\n",
314/// # " b label: `b`,\n",
315/// # " b debug: `13`,\n",
316/// # " x label: `x`,\n",
317/// # " x debug: `3`,\n",
318/// # " Δ: `3`,\n",
319/// # " Δ ≠ x: false",
320/// # );
321/// # assert_eq!(actual, message);
322/// # }
323/// ```
324///
325/// # Module macros
326///
327/// * [`assert_diff_ne_x`](macro@crate::assert_diff_ne_x)
328/// * [`assert_diff_ne_x_as_result`](macro@crate::assert_diff_ne_x_as_result)
329/// * [`debug_assert_diff_ne_x`](macro@crate::debug_assert_diff_ne_x)
330///
331#[macro_export]
332macro_rules! assert_diff_ne_x {
333 ($a:expr, $b:expr, $x:expr $(,)?) => {
334 match $crate::assert_diff_ne_x_as_result!($a, $b, $x) {
335 Ok(x) => x,
336 Err(err) => panic!("{}", err),
337 }
338 };
339 ($a:expr, $b:expr, $x:expr, $($message:tt)+) => {
340 match $crate::assert_diff_ne_x_as_result!($a, $b, $x) {
341 Ok(x) => x,
342 Err(err) => panic!("{}\n{}", format_args!($($message)+), err),
343 }
344 };
345}
346
347#[cfg(test)]
348mod test_assert_diff_ne_x {
349 use std::panic;
350
351 #[test]
352 fn lt() {
353 let a: i8 = 10;
354 let b: i8 = 13;
355 let x: i8 = 4;
356 for _ in 0..1 {
357 let actual = assert_diff_ne_x!(a, b, x);
358 assert_eq!(actual, (3 as i8, 4 as i8));
359 }
360 }
361
362 #[test]
363 fn gt() {
364 let a: i8 = 10;
365 let b: i8 = 13;
366 let x: i8 = 2;
367 for _ in 0..1 {
368 let actual = assert_diff_ne_x!(a, b, x);
369 assert_eq!(actual, (3 as i8, 2 as i8));
370 }
371 }
372
373 #[test]
374 fn eq() {
375 let a: i8 = 10;
376 let b: i8 = 13;
377 let x: i8 = 3;
378 let result = panic::catch_unwind(|| {
379 let _actual = assert_diff_ne_x!(a, b, x);
380 });
381 let message = concat!(
382 "assertion failed: `assert_diff_ne_x!(a, b, x)`\n",
383 "https://docs.rs/assertables/",
384 env!("CARGO_PKG_VERSION"),
385 "/assertables/macro.assert_diff_ne_x.html\n",
386 " a label: `a`,\n",
387 " a debug: `10`,\n",
388 " b label: `b`,\n",
389 " b debug: `13`,\n",
390 " x label: `x`,\n",
391 " x debug: `3`,\n",
392 " Δ: `3`,\n",
393 " Δ ≠ x: false"
394 );
395 assert_eq!(
396 result
397 .unwrap_err()
398 .downcast::<String>()
399 .unwrap()
400 .to_string(),
401 message
402 );
403 }
404
405 #[test]
406 fn overflow() {
407 let a: i8 = i8::MAX;
408 let b: i8 = i8::MIN;
409 let x: i8 = 0;
410 let result = panic::catch_unwind(|| {
411 let _actual = assert_diff_ne_x!(a, b, x);
412 });
413 let message = format!(
414 concat!(
415 "assertion failed: `assert_diff_ne_x!(a, b, x)`\n",
416 "https://docs.rs/assertables/",
417 env!("CARGO_PKG_VERSION"),
418 "/assertables/macro.assert_diff_ne_x.html\n",
419 " a label: `a`,\n",
420 " a debug: `{}`,\n",
421 " b label: `b`,\n",
422 " b debug: `{}`,\n",
423 " x label: `x`,\n",
424 " x debug: `{}`,\n",
425 " Δ: panic"
426 ),
427 a, b, x
428 );
429 assert_eq!(
430 result
431 .unwrap_err()
432 .downcast::<String>()
433 .unwrap()
434 .to_string(),
435 message
436 );
437 }
438}
439
440/// Assert a difference is not equal to an expression.
441///
442/// Pseudocode:<br>
443/// Δ = x
444///
445/// This macro provides the same statements as [`assert_diff_ne_x`](macro.assert_diff_ne_x.html),
446/// except this macro's statements are only enabled in non-optimized
447/// builds by default. An optimized build will not execute this macro's
448/// statements unless `-C debug-assertions` is passed to the compiler.
449///
450/// This macro is useful for checks that are too expensive to be present
451/// in a release build but may be helpful during development.
452///
453/// The result of expanding this macro is always type checked.
454///
455/// An unchecked assertion allows a program in an inconsistent state to
456/// keep running, which might have unexpected consequences but does not
457/// introduce unsafety as long as this only happens in safe code. The
458/// performance cost of assertions, however, is not measurable in general.
459/// Replacing `assert*!` with `debug_assert*!` is thus only encouraged
460/// after thorough profiling, and more importantly, only in safe code!
461///
462/// This macro is intended to work in a similar way to
463/// [`::std::debug_assert`](https://doc.rust-lang.org/std/macro.debug_assert.html).
464///
465/// # Module macros
466///
467/// * [`assert_diff_ne_x`](macro@crate::assert_diff_ne_x)
468/// * [`assert_diff_ne_x_as_result`](macro@crate::assert_diff_ne_x_as_result)
469/// * [`debug_assert_diff_ne_x`](macro@crate::debug_assert_diff_ne_x)
470///
471#[macro_export]
472macro_rules! debug_assert_diff_ne_x {
473 ($($arg:tt)*) => {
474 if $crate::cfg!(debug_assertions) {
475 $crate::assert_diff_ne_x!($($arg)*);
476 }
477 };
478}