assertables/assert_lt.rs
1//! Assert an expression is less than another.
2//!
3//! Pseudocode:<br>
4//! a < b
5//!
6//! # Example
7//!
8//! ```rust
9//! use assertables::*;
10//!
11//! let a = 1;
12//! let b = 2;
13//! assert_lt!(a, b);
14//! ```
15//!
16//! # Module macros
17//!
18//! * [`assert_lt`](macro@crate::assert_lt)
19//! * [`assert_lt_as_result`](macro@crate::assert_lt_as_result)
20//! * [`debug_assert_lt`](macro@crate::debug_assert_lt)
21
22/// Assert an expression is less than another.
23///
24/// Pseudocode:<br>
25/// a < b
26///
27/// * If true, return `Ok(())`.
28///
29/// * Otherwise, return [`Err`] with a message and the values of the
30/// expressions with their debug representations.
31///
32/// This macro is useful for runtime checks, such as checking parameters,
33/// or sanitizing inputs, or handling different results in different ways.
34///
35/// # Module macros
36///
37/// * [`assert_lt`](macro@crate::assert_lt)
38/// * [`assert_lt_as_result`](macro@crate::assert_lt_as_result)
39/// * [`debug_assert_lt`](macro@crate::debug_assert_lt)
40///
41#[macro_export]
42macro_rules! assert_lt_as_result {
43 ($a:expr, $b:expr $(,)?) => {
44 match (&$a, &$b) {
45 (a, b) => {
46 if a < b {
47 Ok(())
48 } else {
49 Err(format!(
50 concat!(
51 "assertion failed: `assert_lt!(a, b)`\n",
52 "https://docs.rs/assertables/9.8.4/assertables/macro.assert_lt.html\n",
53 " a label: `{}`,\n",
54 " a debug: `{:?}`,\n",
55 " b label: `{}`,\n",
56 " b debug: `{:?}`",
57 ),
58 stringify!($a),
59 a,
60 stringify!($b),
61 b
62 ))
63 }
64 }
65 }
66 };
67}
68
69#[cfg(test)]
70mod test_assert_lt_as_result {
71 use std::sync::Once;
72
73 mod integer {
74 use super::*;
75
76 #[test]
77 fn lt() {
78 let a: i8 = 1;
79 let b: i8 = 2;
80 for _ in 0..1 {
81 let actual = assert_lt_as_result!(a, b);
82 assert_eq!(actual.unwrap(), ());
83 }
84 }
85
86 #[test]
87 fn lt_once() {
88 static A: Once = Once::new();
89 fn a() -> i8 {
90 if A.is_completed() {
91 panic!("A.is_completed()")
92 } else {
93 A.call_once(|| {})
94 }
95 1
96 }
97
98 static B: Once = Once::new();
99 fn b() -> i8 {
100 if B.is_completed() {
101 panic!("B.is_completed()")
102 } else {
103 B.call_once(|| {})
104 }
105 2
106 }
107
108 assert_eq!(A.is_completed(), false);
109 assert_eq!(B.is_completed(), false);
110 let result = assert_lt_as_result!(a(), b());
111 assert!(result.is_ok());
112 assert_eq!(A.is_completed(), true);
113 assert_eq!(B.is_completed(), true);
114 }
115
116 #[test]
117 fn eq() {
118 let a: i8 = 1;
119 let b: i8 = 1;
120 let actual = assert_lt_as_result!(a, b);
121 let message = concat!(
122 "assertion failed: `assert_lt!(a, b)`\n",
123 "https://docs.rs/assertables/9.8.4/assertables/macro.assert_lt.html\n",
124 " a label: `a`,\n",
125 " a debug: `1`,\n",
126 " b label: `b`,\n",
127 " b debug: `1`",
128 );
129 assert_eq!(actual.unwrap_err(), message);
130 }
131
132 #[test]
133 fn gt() {
134 let a: i8 = 2;
135 let b: i8 = 1;
136 let actual = assert_lt_as_result!(a, b);
137 let message = concat!(
138 "assertion failed: `assert_lt!(a, b)`\n",
139 "https://docs.rs/assertables/9.8.4/assertables/macro.assert_lt.html\n",
140 " a label: `a`,\n",
141 " a debug: `2`,\n",
142 " b label: `b`,\n",
143 " b debug: `1`",
144 );
145 assert_eq!(actual.unwrap_err(), message);
146 }
147 }
148
149 mod string {
150 use super::*;
151
152 #[test]
153 fn lt() {
154 let a: String = String::from("1");
155 let b: String = String::from("2");
156 for _ in 0..1 {
157 let actual = assert_lt_as_result!(a, b);
158 assert_eq!(actual.unwrap(), ());
159 }
160 }
161
162 #[test]
163 fn lt_once() {
164 static A: Once = Once::new();
165 fn a() -> String {
166 if A.is_completed() {
167 panic!("A.is_completed()")
168 } else {
169 A.call_once(|| {})
170 }
171 String::from("1")
172 }
173
174 static B: Once = Once::new();
175 fn b() -> String {
176 if B.is_completed() {
177 panic!("B.is_completed()")
178 } else {
179 B.call_once(|| {})
180 }
181 String::from("2")
182 }
183
184 assert_eq!(A.is_completed(), false);
185 assert_eq!(B.is_completed(), false);
186 let result = assert_lt_as_result!(a(), b());
187 assert!(result.is_ok());
188 assert_eq!(A.is_completed(), true);
189 assert_eq!(B.is_completed(), true);
190 }
191
192 #[test]
193 fn eq() {
194 let a: String = String::from("1");
195 let b: String = String::from("1");
196 let actual = assert_lt_as_result!(a, b);
197 let message = concat!(
198 "assertion failed: `assert_lt!(a, b)`\n",
199 "https://docs.rs/assertables/9.8.4/assertables/macro.assert_lt.html\n",
200 " a label: `a`,\n",
201 " a debug: `\"1\"`,\n",
202 " b label: `b`,\n",
203 " b debug: `\"1\"`",
204 );
205 assert_eq!(actual.unwrap_err(), message);
206 }
207
208 #[test]
209 fn gt() {
210 let a: String = String::from("2");
211 let b: String = String::from("1");
212 let actual = assert_lt_as_result!(a, b);
213 let message = concat!(
214 "assertion failed: `assert_lt!(a, b)`\n",
215 "https://docs.rs/assertables/9.8.4/assertables/macro.assert_lt.html\n",
216 " a label: `a`,\n",
217 " a debug: `\"2\"`,\n",
218 " b label: `b`,\n",
219 " b debug: `\"1\"`",
220 );
221 assert_eq!(actual.unwrap_err(), message);
222 }
223 }
224}
225
226/// Assert an expression is less than another.
227///
228/// Pseudocode:<br>
229/// a < b
230///
231/// * If true, return `()`.
232///
233/// * Otherwise, call [`panic!`] with a message and the values of the
234/// expressions with their debug representations.
235///
236/// # Examples
237///
238/// ```rust
239/// use assertables::*;
240/// # use std::panic;
241///
242/// # fn main() {
243/// let a = 1;
244/// let b = 2;
245/// assert_lt!(a, b);
246///
247/// # let result = panic::catch_unwind(|| {
248/// // This will panic
249/// let a = 2;
250/// let b = 1;
251/// assert_lt!(a, b);
252/// # });
253/// // assertion failed: `assert_lt!(a, b)`
254/// // https://docs.rs/assertables/…/assertables/macro.assert_lt.html
255/// // a label: `a`,
256/// // a debug: `2`,
257/// // b label: `b`,
258/// // b debug: `1`
259/// # let actual = result.unwrap_err().downcast::<String>().unwrap().to_string();
260/// # let message = concat!(
261/// # "assertion failed: `assert_lt!(a, b)`\n",
262/// # "https://docs.rs/assertables/9.8.4/assertables/macro.assert_lt.html\n",
263/// # " a label: `a`,\n",
264/// # " a debug: `2`,\n",
265/// # " b label: `b`,\n",
266/// # " b debug: `1`",
267/// # );
268/// # assert_eq!(actual, message);
269/// # }
270/// ```
271///
272/// # Module macros
273///
274/// * [`assert_lt`](macro@crate::assert_lt)
275/// * [`assert_lt_as_result`](macro@crate::assert_lt_as_result)
276/// * [`debug_assert_lt`](macro@crate::debug_assert_lt)
277///
278#[macro_export]
279macro_rules! assert_lt {
280 ($a:expr, $b:expr $(,)?) => {
281 match $crate::assert_lt_as_result!($a, $b) {
282 Ok(()) => (),
283 Err(err) => panic!("{}", err),
284 }
285 };
286 ($a:expr, $b:expr, $($message:tt)+) => {
287 match $crate::assert_lt_as_result!($a, $b) {
288 Ok(()) => (),
289 Err(err) => panic!("{}\n{}", format_args!($($message)+), err)
290 }
291 };
292}
293
294#[cfg(test)]
295mod test_assert_lt {
296 use std::panic;
297
298 mod integer {
299 use super::*;
300
301 #[test]
302 fn lt() {
303 let a: i8 = 1;
304 let b: i8 = 2;
305 for _ in 0..1 {
306 let actual = assert_lt!(a, b);
307 assert_eq!(actual, ());
308 }
309 }
310
311 #[test]
312 fn eq() {
313 let a: i8 = 1;
314 let b: i8 = 1;
315 let result = panic::catch_unwind(|| {
316 let _actual = assert_lt!(a, b);
317 });
318 let message = concat!(
319 "assertion failed: `assert_lt!(a, b)`\n",
320 "https://docs.rs/assertables/9.8.4/assertables/macro.assert_lt.html\n",
321 " a label: `a`,\n",
322 " a debug: `1`,\n",
323 " b label: `b`,\n",
324 " b debug: `1`",
325 );
326 assert_eq!(
327 result
328 .unwrap_err()
329 .downcast::<String>()
330 .unwrap()
331 .to_string(),
332 message
333 );
334 }
335
336 #[test]
337 fn gt() {
338 let a: i8 = 2;
339 let b: i8 = 1;
340 let result = panic::catch_unwind(|| {
341 let _actual = assert_lt!(a, b);
342 });
343 let message = concat!(
344 "assertion failed: `assert_lt!(a, b)`\n",
345 "https://docs.rs/assertables/9.8.4/assertables/macro.assert_lt.html\n",
346 " a label: `a`,\n",
347 " a debug: `2`,\n",
348 " b label: `b`,\n",
349 " b debug: `1`",
350 );
351 assert_eq!(
352 result
353 .unwrap_err()
354 .downcast::<String>()
355 .unwrap()
356 .to_string(),
357 message
358 );
359 }
360 }
361
362 mod string {
363 use super::*;
364
365 #[test]
366 fn lt() {
367 let a: String = String::from("1");
368 let b: String = String::from("2");
369 for _ in 0..1 {
370 let actual = assert_lt!(a, b);
371 assert_eq!(actual, ());
372 }
373 }
374
375 #[test]
376 fn eq() {
377 let a: String = String::from("1");
378 let b: String = String::from("1");
379 let result = panic::catch_unwind(|| {
380 let _actual = assert_lt!(a, b);
381 });
382 let message = concat!(
383 "assertion failed: `assert_lt!(a, b)`\n",
384 "https://docs.rs/assertables/9.8.4/assertables/macro.assert_lt.html\n",
385 " a label: `a`,\n",
386 " a debug: `\"1\"`,\n",
387 " b label: `b`,\n",
388 " b debug: `\"1\"`",
389 );
390 assert_eq!(
391 result
392 .unwrap_err()
393 .downcast::<String>()
394 .unwrap()
395 .to_string(),
396 message
397 );
398 }
399
400 #[test]
401 fn gt() {
402 let a: String = String::from("2");
403 let b: String = String::from("1");
404 let result = panic::catch_unwind(|| {
405 let _actual = assert_lt!(a, b);
406 });
407 let message = concat!(
408 "assertion failed: `assert_lt!(a, b)`\n",
409 "https://docs.rs/assertables/9.8.4/assertables/macro.assert_lt.html\n",
410 " a label: `a`,\n",
411 " a debug: `\"2\"`,\n",
412 " b label: `b`,\n",
413 " b debug: `\"1\"`",
414 );
415 assert_eq!(
416 result
417 .unwrap_err()
418 .downcast::<String>()
419 .unwrap()
420 .to_string(),
421 message
422 );
423 }
424 }
425}
426
427/// Assert an expression is less than another.
428///
429/// Pseudocode:<br>
430/// a < b
431///
432/// This macro provides the same statements as [`assert_lt`](macro.assert_lt.html),
433/// except this macro's statements are only enabled in non-optimized
434/// builds by default. An optimized build will not execute this macro's
435/// statements unless `-C debug-assertions` is passed to the compiler.
436///
437/// This macro is useful for checks that are too expensive to be present
438/// in a release build but may be helpful during development.
439///
440/// The result of expanding this macro is always type checked.
441///
442/// An unchecked assertion allows a program in an inconsistent state to
443/// keep running, which might have unexpected consequences but does not
444/// introduce unsafety as long as this only happens in safe code. The
445/// performance cost of assertions, however, is not measurable in general.
446/// Replacing `assert*!` with `debug_assert*!` is thus only encouraged
447/// after thorough profiling, and more importantly, only in safe code!
448///
449/// This macro is intended to work in a similar way to
450/// [`::std::debug_assert`](https://doc.rust-lang.org/std/macro.debug_assert.html).
451///
452/// # Module macros
453///
454/// * [`assert_lt`](macro@crate::assert_lt)
455/// * [`assert_lt`](macro@crate::assert_lt)
456/// * [`debug_assert_lt`](macro@crate::debug_assert_lt)
457///
458#[macro_export]
459macro_rules! debug_assert_lt {
460 ($($arg:tt)*) => {
461 if $crate::cfg!(debug_assertions) {
462 $crate::assert_lt!($($arg)*);
463 }
464 };
465}