├── .gitignore ├── xtask ├── src │ ├── tidy.rs │ └── main.rs └── Cargo.toml ├── README.md ├── .github └── workflows │ └── ci.yaml ├── Cargo.toml ├── LICENSE-MIT ├── tests └── smoke.rs ├── LICENSE-APACHE └── src └── lib.rs /.gitignore: -------------------------------------------------------------------------------- 1 | /target 2 | /ci 3 | Cargo.lock 4 | -------------------------------------------------------------------------------- /xtask/src/tidy.rs: -------------------------------------------------------------------------------- 1 | use xshell::{cmd, Shell}; 2 | 3 | #[test] 4 | fn test_formatting() { 5 | let sh = Shell::new().unwrap(); 6 | cmd!(sh, "cargo fmt --all -- --check").run().unwrap() 7 | } 8 | -------------------------------------------------------------------------------- /xtask/Cargo.toml: -------------------------------------------------------------------------------- 1 | [package] 2 | name = "xtask" 3 | version = "0.0.0" 4 | publish = false 5 | authors = ["Aleksey Kladov "] 6 | edition = "2018" 7 | 8 | [dependencies] 9 | xshell = "0.2.6" 10 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # cov-mark 2 | 3 | Verify that your tests exercise the conditions you think they are exercising 4 | 5 | ```rust 6 | fn safe_divide(dividend: u32, divisor: u32) -> u32 { 7 | if divisor == 0 { 8 | cov_mark::hit!(save_divide_zero); 9 | return 0; 10 | } 11 | dividend / divisor 12 | } 13 | 14 | #[test] 15 | fn test_safe_divide_by_zero() { 16 | cov_mark::check!(save_divide_zero); 17 | assert_eq!(safe_divide(92, 0), 0); 18 | } 19 | ``` 20 | 21 | See [the docs](https://docs.rs/cov-mark) for details 22 | -------------------------------------------------------------------------------- /.github/workflows/ci.yaml: -------------------------------------------------------------------------------- 1 | name: CI 2 | on: 3 | pull_request: 4 | push: 5 | branches: ["master"] 6 | 7 | env: 8 | CARGO_INCREMENTAL: 0 9 | CARGO_NET_RETRY: 10 10 | CI: 1 11 | RUST_BACKTRACE: short 12 | RUSTFLAGS: -D warnings 13 | RUSTUP_MAX_RETRIES: 10 14 | 15 | jobs: 16 | test: 17 | name: Rust 18 | runs-on: ubuntu-latest 19 | 20 | steps: 21 | - uses: actions/checkout@v2 22 | with: 23 | fetch-depth: 0 # fetch tags for publish 24 | - run: rustup default 1.63 25 | - run: cargo run -p xtask 26 | env: 27 | CARGO_REGISTRY_TOKEN: ${{ secrets.CRATES_IO_TOKEN }} 28 | -------------------------------------------------------------------------------- /Cargo.toml: -------------------------------------------------------------------------------- 1 | [package] 2 | name = "cov-mark" 3 | version = "2.2.0" 4 | description = "Manual coverage marks." 5 | keywords = ["coverage", "test"] 6 | categories = ["development-tools"] 7 | license = "MIT OR Apache-2.0" 8 | repository = "https://github.com/matklad/cov-mark" 9 | documentation = "https://docs.rs/cov-mark" 10 | authors = [ 11 | "Aleksey Kladov ", 12 | "Simonas Kazlauskas " 13 | ] 14 | edition = "2021" 15 | rust-version = "1.63" 16 | 17 | exclude = [".github/", "bors.toml", "rustfmt.toml"] 18 | 19 | [workspace] 20 | members = ["xtask"] 21 | 22 | [features] 23 | default = ["enable"] 24 | enable = [] 25 | 26 | [package.metadata.docs.rs] 27 | all-features = true 28 | rustdoc-args = ["--cfg", "nightly_docs"] 29 | -------------------------------------------------------------------------------- /LICENSE-MIT: -------------------------------------------------------------------------------- 1 | Permission is hereby granted, free of charge, to any 2 | person obtaining a copy of this software and associated 3 | documentation files (the "Software"), to deal in the 4 | Software without restriction, including without 5 | limitation the rights to use, copy, modify, merge, 6 | publish, distribute, sublicense, and/or sell copies of 7 | the Software, and to permit persons to whom the Software 8 | is furnished to do so, subject to the following 9 | conditions: 10 | 11 | The above copyright notice and this permission notice 12 | shall be included in all copies or substantial portions 13 | of the Software. 14 | 15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF 16 | ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED 17 | TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A 18 | PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT 19 | SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY 20 | CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 21 | OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR 22 | IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 23 | DEALINGS IN THE SOFTWARE. 24 | -------------------------------------------------------------------------------- /tests/smoke.rs: -------------------------------------------------------------------------------- 1 | fn safe_divide(dividend: u32, divisor: u32) -> u32 { 2 | if divisor == 0 { 3 | cov_mark::hit!(safe_divide_zero); 4 | return 0; 5 | } 6 | dividend / divisor 7 | } 8 | 9 | #[test] 10 | fn test_safe_divide_by_zero() { 11 | cov_mark::check!(safe_divide_zero); 12 | assert_eq!(safe_divide(92, 0), 0); 13 | } 14 | 15 | struct CoveredDropper; 16 | impl Drop for CoveredDropper { 17 | fn drop(&mut self) { 18 | cov_mark::hit!(covered_dropper_drops); 19 | } 20 | } 21 | 22 | #[test] 23 | fn test_drop_count() { 24 | cov_mark::check_count!(covered_dropper_drops, 2); 25 | let _covered_dropper1 = CoveredDropper; 26 | let _covered_dropper2 = CoveredDropper; 27 | } 28 | 29 | #[test] 30 | #[should_panic(expected = "mark covered_dropper_drops was hit 2 times, expected 1")] 31 | fn test_drop_count_fail() { 32 | cov_mark::check_count!(covered_dropper_drops, 1); 33 | let _covered_dropper1 = CoveredDropper; 34 | let _covered_dropper2 = CoveredDropper; 35 | } 36 | 37 | #[test] 38 | fn test_mark_survey() { 39 | let _survey = cov_mark::survey(); 40 | cov_mark::check_count!(covered_dropper_drops, 2); 41 | let _covered_dropper1 = CoveredDropper; 42 | let _covered_dropper2 = CoveredDropper; 43 | } 44 | -------------------------------------------------------------------------------- /xtask/src/main.rs: -------------------------------------------------------------------------------- 1 | #[cfg(test)] 2 | mod tidy; 3 | 4 | use std::time::Instant; 5 | 6 | use xshell::{cmd, Shell}; 7 | 8 | fn main() -> xshell::Result<()> { 9 | let sh = Shell::new()?; 10 | 11 | cmd!(sh, "rustup toolchain install stable --no-self-update").run()?; 12 | let _e = sh.push_env("RUSTUP_TOOLCHAIN", "stable"); 13 | cmd!(sh, "rustc --version").run()?; 14 | 15 | { 16 | let _s = section("BUILD"); 17 | cmd!(sh, "cargo test --workspace --no-run").run()?; 18 | } 19 | 20 | { 21 | let _s = section("TEST"); 22 | cmd!(sh, "cargo test --workspace -- --nocapture").run()?; 23 | } 24 | 25 | { 26 | let _s = section("PUBLISH"); 27 | 28 | let version = cmd!(sh, "cargo pkgid -p cov-mark") 29 | .read()? 30 | .rsplit_once('#') 31 | .unwrap() 32 | .1 33 | .to_string(); 34 | let tag = format!("v{version}"); 35 | 36 | let current_branch = cmd!(sh, "git branch --show-current").read()?; 37 | let tag_exists = cmd!(sh, "git tag --list") 38 | .read()? 39 | .split_ascii_whitespace() 40 | .any(|it| it == &tag); 41 | 42 | if current_branch == "master" && !tag_exists { 43 | cmd!(sh, "git tag v{version}").run()?; 44 | cmd!(sh, "cargo publish -p cov-mark").run()?; 45 | cmd!(sh, "git push --tags").run()?; 46 | } 47 | } 48 | 49 | Ok(()) 50 | } 51 | 52 | fn section(name: &'static str) -> impl Drop { 53 | println!("::group::{name}"); 54 | let start = Instant::now(); 55 | defer(move || { 56 | let elapsed = start.elapsed(); 57 | eprintln!("{name}: {elapsed:.2?}"); 58 | println!("::endgroup::"); 59 | }) 60 | } 61 | 62 | fn defer(f: F) -> impl Drop { 63 | struct D(Option); 64 | impl Drop for D { 65 | fn drop(&mut self) { 66 | if let Some(f) = self.0.take() { 67 | f() 68 | } 69 | } 70 | } 71 | D(Some(f)) 72 | } 73 | -------------------------------------------------------------------------------- /LICENSE-APACHE: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. 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We also recommend that a 185 | file or class name and description of purpose be included on the 186 | same "printed page" as the copyright notice for easier 187 | identification within third-party archives. 188 | 189 | Copyright [yyyy] [name of copyright owner] 190 | 191 | Licensed under the Apache License, Version 2.0 (the "License"); 192 | you may not use this file except in compliance with the License. 193 | You may obtain a copy of the License at 194 | 195 | http://www.apache.org/licenses/LICENSE-2.0 196 | 197 | Unless required by applicable law or agreed to in writing, software 198 | distributed under the License is distributed on an "AS IS" BASIS, 199 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 200 | See the License for the specific language governing permissions and 201 | limitations under the License. 202 | -------------------------------------------------------------------------------- /src/lib.rs: -------------------------------------------------------------------------------- 1 | //! # cov-mark 2 | //! 3 | //! This library at its core provides two macros, [`hit!`] and [`check!`], 4 | //! which can be used to verify that a certain test exercises a certain code 5 | //! path. 6 | //! 7 | //! Here's a short example: 8 | //! 9 | //! ``` 10 | //! fn parse_date(s: &str) -> Option<(u32, u32, u32)> { 11 | //! if 10 != s.len() { 12 | //! // By using `cov_mark::hit!` 13 | //! // we signal which test exercises this code. 14 | //! cov_mark::hit!(short_date); 15 | //! return None; 16 | //! } 17 | //! 18 | //! if "-" != &s[4..5] || "-" != &s[7..8] { 19 | //! cov_mark::hit!(bad_dashes); 20 | //! return None; 21 | //! } 22 | //! // ... 23 | //! # unimplemented!() 24 | //! } 25 | //! 26 | //! #[test] 27 | //! fn test_parse_date() { 28 | //! { 29 | //! // `cov_mark::check!` creates a guard object 30 | //! // that verifies that by the end of the scope we've 31 | //! // executed the corresponding `cov_mark::hit`. 32 | //! cov_mark::check!(short_date); 33 | //! assert!(parse_date("92").is_none()); 34 | //! } 35 | //! 36 | //! // This will fail. Although the test looks like 37 | //! // it exercises the second condition, it does not. 38 | //! // The call to `check!` call catches this bug in the test. 39 | //! // { 40 | //! // cov_mark::check!(bad_dashes); 41 | //! // assert!(parse_date("27.2.2013").is_none()); 42 | //! // } 43 | //! 44 | //! { 45 | //! cov_mark::check!(bad_dashes); 46 | //! assert!(parse_date("27.02.2013").is_none()); 47 | //! } 48 | //! } 49 | //! 50 | //! # fn main() {} 51 | //! ``` 52 | //! 53 | //! Here's why coverage marks are useful: 54 | //! 55 | //! * Verifying that something doesn't happen for the *right* reason. 56 | //! * Finding the test that exercises the code (grep for `check!(mark_name)`). 57 | //! * Finding the code that the test is supposed to check (grep for `hit!(mark_name)`). 58 | //! * Making sure that code and tests don't diverge during refactorings. 59 | //! * (If used pervasively) Verifying that each branch has a corresponding test. 60 | //! 61 | //! # Limitations 62 | //! 63 | //! * Names of marks must be globally unique. 64 | //! 65 | //! # Implementation Details 66 | //! 67 | //! Each coverage mark is an `AtomicUsize` counter. [`hit!`] increments 68 | //! this counter, [`check!`] returns a guard object which checks that 69 | //! the mark was incremented. 70 | //! Each counter is stored as a thread-local, allowing for accurate per-thread 71 | //! counting. 72 | //! 73 | //! # Porting existing tests to cov-mark 74 | //! 75 | //! When incrementally outfitting a set of tests with markers, [`survey`] may be useful. 76 | 77 | #![deny(rustdoc::broken_intra_doc_links)] 78 | #![allow(clippy::test_attr_in_doctest)] 79 | 80 | /// Hit a mark with a specified name. 81 | /// 82 | /// # Example 83 | /// 84 | /// ``` 85 | /// fn safe_divide(dividend: u32, divisor: u32) -> u32 { 86 | /// if divisor == 0 { 87 | /// cov_mark::hit!(safe_divide_zero); 88 | /// return 0; 89 | /// } 90 | /// dividend / divisor 91 | /// } 92 | /// ``` 93 | #[macro_export] 94 | macro_rules! hit { 95 | ($ident:ident) => { 96 | $crate::__rt::hit(stringify!($ident)) 97 | }; 98 | } 99 | 100 | /// Checks that a specified mark was hit. 101 | /// 102 | /// # Example 103 | /// 104 | /// ``` 105 | /// #[test] 106 | /// fn test_safe_divide_by_zero() { 107 | /// cov_mark::check!(safe_divide_zero); 108 | /// assert_eq!(safe_divide(92, 0), 0); 109 | /// } 110 | /// # fn safe_divide(dividend: u32, divisor: u32) -> u32 { 111 | /// # if divisor == 0 { 112 | /// # cov_mark::hit!(safe_divide_zero); 113 | /// # return 0; 114 | /// # } 115 | /// # dividend / divisor 116 | /// # } 117 | /// ``` 118 | #[macro_export] 119 | macro_rules! check { 120 | ($ident:ident) => { 121 | let _guard = $crate::__rt::Guard::new(stringify!($ident), None, $crate::assert!()); 122 | }; 123 | } 124 | 125 | /// Checks that a specified mark was hit exactly the specified number of times. 126 | /// 127 | /// # Example 128 | /// 129 | /// ``` 130 | /// struct CoveredDropper; 131 | /// impl Drop for CoveredDropper { 132 | /// fn drop(&mut self) { 133 | /// cov_mark::hit!(covered_dropper_drops); 134 | /// } 135 | /// } 136 | /// 137 | /// #[test] 138 | /// fn drop_count_test() { 139 | /// cov_mark::check_count!(covered_dropper_drops, 2); 140 | /// let _covered_dropper1 = CoveredDropper; 141 | /// let _covered_dropper2 = CoveredDropper; 142 | /// } 143 | /// ``` 144 | #[macro_export] 145 | macro_rules! check_count { 146 | ($ident:ident, $count: literal) => { 147 | let _guard = $crate::__rt::Guard::new(stringify!($ident), Some($count), $crate::assert!()); 148 | }; 149 | } 150 | 151 | /// Survey which marks are hit. 152 | /// 153 | /// # Example 154 | /// 155 | /// ``` 156 | /// struct CoveredDropper; 157 | /// impl Drop for CoveredDropper { 158 | /// fn drop(&mut self) { 159 | /// cov_mark::hit!(covered_dropper_drops); 160 | /// } 161 | /// } 162 | /// 163 | /// # fn safe_divide(dividend: u32, divisor: u32) -> u32 { 164 | /// # if divisor == 0 { 165 | /// # cov_mark::hit!(safe_divide_zero); 166 | /// # return 0; 167 | /// # } 168 | /// # dividend / divisor 169 | /// # } 170 | /// 171 | /// #[test] 172 | /// fn drop_count_test() { 173 | /// let _survey = cov_mark::survey(); // sets a drop guard that tracks hits 174 | /// let _covered_dropper1 = CoveredDropper; 175 | /// let _covered_dropper2 = CoveredDropper; 176 | /// safe_divide(92, 0); 177 | /// // prints 178 | /// // "mark safe_divide_zero ... hit once" 179 | /// // "mark covered_dropper_drops ... hit 2 times" 180 | /// } 181 | /// ``` 182 | pub fn survey() -> __rt::SurveyGuard { 183 | __rt::SurveyGuard::new() 184 | } 185 | 186 | #[doc(hidden)] 187 | #[macro_export] 188 | macro_rules! assert { 189 | () => { 190 | |expected_hits, hit_count, mark| match expected_hits { 191 | Some(hits) => assert!( 192 | hit_count == hits, 193 | "mark {mark} was hit {hit_count} times, expected {hits}" 194 | ), 195 | None => assert!(hit_count > 0, "mark {mark} was not hit"), 196 | } 197 | }; 198 | } 199 | 200 | #[doc(hidden)] 201 | pub type AssertCallback = fn(Option, usize, &'static str); 202 | 203 | #[doc(hidden)] 204 | #[cfg(feature = "enable")] 205 | pub mod __rt { 206 | use std::{ 207 | cell::RefCell, 208 | sync::atomic::{AtomicUsize, Ordering::Relaxed}, 209 | }; 210 | 211 | use super::AssertCallback; 212 | 213 | /// Even with 214 | /// , 215 | /// a `thread_local` generates significantly more verbose assembly on x86 216 | /// than atomic, so we'll use atomic for the fast path 217 | static LEVEL: AtomicUsize = AtomicUsize::new(0); 218 | const SURVEY_LEVEL: usize = !(usize::MAX >> 1); 219 | 220 | thread_local! { 221 | static ACTIVE: RefCell> = const { RefCell::new(Vec::new()) }; 222 | static SURVEY_RESPONSE: RefCell> = const { RefCell::new(Vec::new()) }; 223 | } 224 | 225 | #[inline(always)] 226 | pub fn hit(key: &'static str) { 227 | let level = LEVEL.load(Relaxed); 228 | if level > 0 { 229 | if level >= SURVEY_LEVEL { 230 | add_to_survey(key); 231 | } 232 | hit_cold(key); 233 | } 234 | 235 | #[cold] 236 | fn hit_cold(key: &'static str) { 237 | ACTIVE.with(|it| it.borrow_mut().iter_mut().for_each(|g| g.hit(key))) 238 | } 239 | 240 | #[cold] 241 | fn add_to_survey(mark: &'static str) { 242 | SURVEY_RESPONSE.with(|it| { 243 | let mut it = it.borrow_mut(); 244 | for survey in it.iter_mut() { 245 | if survey.mark == mark { 246 | survey.hits = survey.hits.saturating_add(1); 247 | return; 248 | } 249 | } 250 | it.push(GuardInner { 251 | mark, 252 | hits: 1, 253 | expected_hits: None, 254 | }); 255 | }); 256 | } 257 | } 258 | 259 | #[derive(PartialEq, Eq, PartialOrd, Ord)] 260 | struct GuardInner { 261 | mark: &'static str, 262 | hits: usize, 263 | expected_hits: Option, 264 | } 265 | 266 | pub struct Guard { 267 | mark: &'static str, 268 | f: AssertCallback, 269 | } 270 | 271 | impl GuardInner { 272 | fn hit(&mut self, key: &'static str) { 273 | if key == self.mark { 274 | self.hits = self.hits.saturating_add(1); 275 | } 276 | } 277 | } 278 | 279 | impl Guard { 280 | // macro expansion inserts a [`AssertCallback`] defined in user code, so the panic location 281 | // points to user code instead of cov-mark internals 282 | pub fn new(mark: &'static str, expected_hits: Option, f: AssertCallback) -> Guard { 283 | LEVEL.fetch_add(1, Relaxed); 284 | ACTIVE.with(|it| { 285 | it.borrow_mut().push(GuardInner { 286 | mark, 287 | hits: 0, 288 | expected_hits, 289 | }) 290 | }); 291 | Guard { mark, f } 292 | } 293 | } 294 | 295 | impl Drop for Guard { 296 | fn drop(&mut self) { 297 | LEVEL.fetch_sub(1, Relaxed); 298 | let last = ACTIVE.with(|it| it.borrow_mut().pop()); 299 | 300 | if std::thread::panicking() { 301 | return; 302 | } 303 | 304 | let last = last.unwrap(); 305 | assert_eq!(last.mark, self.mark); 306 | let hit_count = last.hits; 307 | (self.f)(last.expected_hits, hit_count, self.mark) 308 | } 309 | } 310 | 311 | pub struct SurveyGuard; 312 | 313 | impl SurveyGuard { 314 | #[allow(clippy::new_without_default)] 315 | pub fn new() -> SurveyGuard { 316 | LEVEL.fetch_or(SURVEY_LEVEL, Relaxed); 317 | SurveyGuard 318 | } 319 | } 320 | 321 | impl Drop for SurveyGuard { 322 | fn drop(&mut self) { 323 | LEVEL.fetch_and(!SURVEY_LEVEL, Relaxed); 324 | 325 | if std::thread::panicking() { 326 | return; 327 | } 328 | 329 | SURVEY_RESPONSE.with(|it| { 330 | let mut it = it.borrow_mut(); 331 | it.sort(); 332 | for g in it.iter() { 333 | let hit_count = g.hits; 334 | if hit_count == 1 { 335 | eprintln!("mark {} ... hit once", g.mark); 336 | } else if 1 < hit_count { 337 | eprintln!("mark {} ... hit {} times", g.mark, hit_count); 338 | } 339 | } 340 | it.clear(); 341 | }); 342 | } 343 | } 344 | } 345 | 346 | #[doc(hidden)] 347 | #[cfg(not(feature = "enable"))] 348 | pub mod __rt { 349 | #[inline(always)] 350 | pub fn hit(_: &'static str) {} 351 | 352 | #[non_exhaustive] 353 | pub struct Guard; 354 | 355 | impl Guard { 356 | pub fn new(_: &'static str, _: Option, _: super::AssertCallback) -> Guard { 357 | Guard 358 | } 359 | } 360 | 361 | pub struct SurveyGuard; 362 | 363 | impl SurveyGuard { 364 | #[allow(clippy::new_without_default)] 365 | pub fn new() -> SurveyGuard { 366 | SurveyGuard 367 | } 368 | } 369 | } 370 | --------------------------------------------------------------------------------