assertables/assert_err/assert_err_eq.rs
1//! Assert two expressions are Err and their values are equal.
2//!
3//! Pseudocode:<br>
4//! (a ⇒ Err(a1) ⇒ a1) = (b ⇒ Err(b1) ⇒ b1)
5//!
6//! # Example
7//!
8//! ```rust
9//! use assertables::*;
10//!
11//! let a: Result<i8, i8> = Err(1);
12//! let b: Result<i8, i8> = Err(1);
13//! assert_err_eq!(a, b);
14//! ```
15//!
16//! # Module macros
17//!
18//! * [`assert_err_eq`](macro@crate::assert_err_eq)
19//! * [`assert_err_eq_as_result`](macro@crate::assert_err_eq_as_result)
20//! * [`debug_assert_err_eq`](macro@crate::debug_assert_err_eq)
21
22/// Assert two expressions are Err and their values are equal.
23///
24/// Pseudocode:<br>
25/// (a ⇒ Err(a1) ⇒ a1) = (b ⇒ Err(b1) ⇒ b1)
26///
27/// * If true, return Result `Ok((a1, b1))`.
28///
29/// * Otherwise, return Result `Err(message)`.
30///
31/// This macro is useful for runtime checks, such as checking parameters,
32/// or sanitizing inputs, or handling different results in different ways.
33///
34/// # Module macros
35///
36/// * [`assert_err_eq`](macro@crate::assert_err_eq)
37/// * [`assert_err_eq_as_result`](macro@crate::assert_err_eq_as_result)
38/// * [`debug_assert_err_eq`](macro@crate::debug_assert_err_eq)
39///
40#[macro_export]
41macro_rules! assert_err_eq_as_result {
42 ($a:expr, $b:expr $(,)?) => {
43 match($a, $b) {
44 (a, b) => {
45 match (a, b) {
46 (Err(a1), Err(b1)) => {
47 if a1 == b1 {
48 Ok((a1, b1))
49 } else {
50 Err(
51 format!(
52 concat!(
53 "assertion failed: `assert_err_eq!(a, b)`\n",
54 "https://docs.rs/assertables/9.6.0/assertables/macro.assert_err_eq.html\n",
55 " a label: `{}`,\n",
56 " a debug: `{:?}`,\n",
57 " a inner: `{:?}`,\n",
58 " b label: `{}`,\n",
59 " b debug: `{:?}`,\n",
60 " b inner: `{:?}`"
61 ),
62 stringify!($a),
63 a,
64 a1,
65 stringify!($b),
66 b,
67 b1
68 )
69 )
70 }
71 },
72 _ => {
73 Err(
74 format!(
75 concat!(
76 "assertion failed: `assert_err_eq!(a, b)`\n",
77 "https://docs.rs/assertables/9.6.0/assertables/macro.assert_err_eq.html\n",
78 " a label: `{}`,\n",
79 " a debug: `{:?}`,\n",
80 " b label: `{}`,\n",
81 " b debug: `{:?}`",
82 ),
83 stringify!($a),
84 a,
85 stringify!($b),
86 b,
87 )
88 )
89 }
90 }
91 }
92 }
93 };
94}
95
96#[cfg(test)]
97mod test_assert_err_eq_as_result {
98 use std::sync::Once;
99
100 #[test]
101 fn eq() {
102 let a: Result<i8, i8> = Err(1);
103 let b: Result<i8, i8> = Err(1);
104 let actual = assert_err_eq_as_result!(a, b);
105 assert_eq!(actual.unwrap(), (1, 1));
106 }
107
108 #[test]
109 fn eq_once() {
110
111 static A: Once = Once::new();
112 fn a() -> Result<i8, i8> {
113 if A.is_completed() { panic!("A.is_completed()") } else { A.call_once(|| {}) }
114 Err(1)
115 }
116
117 static B: Once = Once::new();
118 fn b() -> Result<i8, i8> {
119 if B.is_completed() { panic!("B.is_completed()") } else { B.call_once(|| {}) }
120 Err(1)
121 }
122
123 assert_eq!(A.is_completed(), false);
124 assert_eq!(B.is_completed(), false);
125 let result = assert_err_eq_as_result!(a(), b());
126 assert!(result.is_ok());
127 assert_eq!(A.is_completed(), true);
128 assert_eq!(B.is_completed(), true);
129
130 }
131
132 #[test]
133 fn ne() {
134 let a: Result<i8, i8> = Err(1);
135 let b: Result<i8, i8> = Err(2);
136 let actual = assert_err_eq_as_result!(a, b);
137 let message = concat!(
138 "assertion failed: `assert_err_eq!(a, b)`\n",
139 "https://docs.rs/assertables/9.6.0/assertables/macro.assert_err_eq.html\n",
140 " a label: `a`,\n",
141 " a debug: `Err(1)`,\n",
142 " a inner: `1`,\n",
143 " b label: `b`,\n",
144 " b debug: `Err(2)`,\n",
145 " b inner: `2`",
146 );
147 assert_eq!(actual.unwrap_err(), message);
148 }
149
150 #[test]
151 fn failure_because_not_err() {
152 let a: Result<i8, i8> = Ok(1);
153 let b: Result<i8, i8> = Err(1);
154 let actual = assert_err_eq_as_result!(a, b);
155 let message = concat!(
156 "assertion failed: `assert_err_eq!(a, b)`\n",
157 "https://docs.rs/assertables/9.6.0/assertables/macro.assert_err_eq.html\n",
158 " a label: `a`,\n",
159 " a debug: `Ok(1)`,\n",
160 " b label: `b`,\n",
161 " b debug: `Err(1)`",
162 );
163 assert_eq!(actual.unwrap_err(), message);
164 }
165
166}
167
168/// Assert two expressions are Err and their values are equal.
169///
170/// Pseudocode:<br>
171/// (a ⇒ Err(a1) ⇒ a1) = (b ⇒ Err(b1) ⇒ b1)
172///
173/// * If true, return `(a1, b1)`.
174///
175/// * Otherwise, call [`panic!`] with a message and the values of the
176/// expressions with their debug representations.
177///
178/// # Examples
179///
180/// ```rust
181/// use assertables::*;
182/// # use std::panic;
183///
184/// # fn main() {
185/// let a: Result<i8, i8> = Err(1);
186/// let b: Result<i8, i8> = Err(1);
187/// assert_err_eq!(a, b);
188///
189/// # let result = panic::catch_unwind(|| {
190/// // This will panic
191/// let a: Result<i8, i8> = Err(1);
192/// let b: Result<i8, i8> = Err(2);
193/// assert_err_eq!(a, b);
194/// # });
195/// // assertion failed: `assert_err_eq!(a, b)`
196/// // https://docs.rs/assertables/9.6.0/assertables/macro.assert_err_eq.html
197/// // a label: `a`,
198/// // a debug: `Err(1)`,
199/// // a inner: `1`,
200/// // b label: `b`,
201/// // b debug: `Err(2)`,
202/// // b inner: `2`
203/// # let actual = result.unwrap_err().downcast::<String>().unwrap().to_string();
204/// # let message = concat!(
205/// # "assertion failed: `assert_err_eq!(a, b)`\n",
206/// # "https://docs.rs/assertables/9.6.0/assertables/macro.assert_err_eq.html\n",
207/// # " a label: `a`,\n",
208/// # " a debug: `Err(1)`,\n",
209/// # " a inner: `1`,\n",
210/// # " b label: `b`,\n",
211/// # " b debug: `Err(2)`,\n",
212/// # " b inner: `2`",
213/// # );
214/// # assert_eq!(actual, message);
215/// # }
216/// ```
217///
218/// # Module macros
219///
220/// * [`assert_err_eq`](macro@crate::assert_err_eq)
221/// * [`assert_err_eq_as_result`](macro@crate::assert_err_eq_as_result)
222/// * [`debug_assert_err_eq`](macro@crate::debug_assert_err_eq)
223///
224#[macro_export]
225macro_rules! assert_err_eq {
226 ($a:expr, $b:expr $(,)?) => {
227 match $crate::assert_err_eq_as_result!($a, $b) {
228 Ok(x) => x,
229 Err(err) => panic!("{}", err),
230 }
231 };
232 ($a:expr, $b:expr, $($message:tt)+) => {
233 match $crate::assert_err_eq_as_result!($a, $b) {
234 Ok(x) => x,
235 Err(err) => panic!("{}\n{}", format_args!($($message)+), err),
236 }
237 };
238}
239
240#[cfg(test)]
241mod test_assert_err_eq {
242 use std::panic;
243
244 #[test]
245 fn success() {
246 let a: Result<i8, i8> = Err(1);
247 let b: Result<i8, i8> = Err(1);
248 let actual = assert_err_eq!(a, b);
249 assert_eq!(actual, (1, 1));
250 }
251
252 #[test]
253 fn ne() {
254 let result = panic::catch_unwind(|| {
255 let a: Result<i8, i8> = Err(1);
256 let b: Result<i8, i8> = Err(2);
257 let _actual = assert_err_eq!(a, b);
258 });
259 let message = concat!(
260 "assertion failed: `assert_err_eq!(a, b)`\n",
261 "https://docs.rs/assertables/9.6.0/assertables/macro.assert_err_eq.html\n",
262 " a label: `a`,\n",
263 " a debug: `Err(1)`,\n",
264 " a inner: `1`,\n",
265 " b label: `b`,\n",
266 " b debug: `Err(2)`,\n",
267 " b inner: `2`",
268 );
269 assert_eq!(
270 result
271 .unwrap_err()
272 .downcast::<String>()
273 .unwrap()
274 .to_string(),
275 message
276 );
277 }
278
279 #[test]
280 fn failure_because_not_err() {
281 let result = panic::catch_unwind(|| {
282 let a: Result<i8, i8> = Ok(1);
283 let b: Result<i8, i8> = Err(1);
284 let _actual = assert_err_eq!(a, b);
285 });
286 let message = concat!(
287 "assertion failed: `assert_err_eq!(a, b)`\n",
288 "https://docs.rs/assertables/9.6.0/assertables/macro.assert_err_eq.html\n",
289 " a label: `a`,\n",
290 " a debug: `Ok(1)`,\n",
291 " b label: `b`,\n",
292 " b debug: `Err(1)`",
293 );
294 assert_eq!(
295 result
296 .unwrap_err()
297 .downcast::<String>()
298 .unwrap()
299 .to_string(),
300 message
301 );
302 }
303}
304
305/// Assert two expressions are Err and their values are equal.
306///
307/// Pseudocode:<br>
308/// (a ⇒ Err(a1) ⇒ a1) = (b ⇒ Err(b1) ⇒ b1)
309///
310/// This macro provides the same statements as [`assert_err_eq`](macro.assert_err_eq.html),
311/// except this macro's statements are only enabled in non-optimized
312/// builds by default. An optimized build will not execute this macro's
313/// statements unless `-C debug-assertions` is passed to the compiler.
314///
315/// This macro is useful for checks that are too expensive to be present
316/// in a release build but may be helpful during development.
317///
318/// The result of expanding this macro is always type checked.
319///
320/// An unchecked assertion allows a program in an inconsistent state to
321/// keep running, which might have unexpected consequences but does not
322/// introduce unsafety as long as this only happens in safe code. The
323/// performance cost of assertions, however, is not measurable in general.
324/// Replacing `assert*!` with `debug_assert*!` is thus only encouraged
325/// after thorough profiling, and more importantly, only in safe code!
326///
327/// This macro is intended to work in a similar way to
328/// [`::std::debug_assert`](https://doc.rust-lang.org/std/macro.debug_assert.html).
329///
330/// # Module macros
331///
332/// * [`assert_err_eq`](macro@crate::assert_err_eq)
333/// * [`assert_err_eq`](macro@crate::assert_err_eq)
334/// * [`debug_assert_err_eq`](macro@crate::debug_assert_err_eq)
335///
336#[macro_export]
337macro_rules! debug_assert_err_eq {
338 ($($arg:tt)*) => {
339 if $crate::cfg!(debug_assertions) {
340 $crate::assert_err_eq!($($arg)*);
341 }
342 };
343}