The doctest example off Rust-lang's rust-by-example page doesn't work, ironically hehe. How do I use doctesting? I successfully learned how to do unit testing in Rust, the chapter before doctesting. https://doc.rust-lang.org/rust-by-example/testing/doc_testing.html
fn main() {
println!("Hello 3+2: {}", add(3,2));
}
/// First line is a short summary describing function.
///
/// The next lines present detailed documentation. Code blocks start with
/// triple backquotes and have implicit `fn main()` inside
/// and `extern crate <cratename>`. Assume we're testing `doccomments` crate:
///
/// ```
/// let result = doccomments::add(2, 3);
/// assert_eq!(result, 5);
/// ```
pub fn add(a: i32, b: i32) -> i32 {
a + b
}
Doctest to run (and pass or fail accordingly)
Doctest doesn't run. Not sure if it's possible to run a doctest in the rust playground due to this crate/module error.
cargo run)stdout:
Hello 3+2: 5
stderr:
Compiling playground v0.0.1 (/playground)
Finished dev [unoptimized + debuginfo] target(s) in 0.70s
Running `target/debug/playground`
cargo test)stdout:
running 0 tests
test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
running 1 test
test src/lib.rs - add (line 11) ... FAILED
failures:
---- src/lib.rs - add (line 11) stdout ----
error[E0433]: failed to resolve: use of undeclared crate or module `doccomments`
--> src/lib.rs:12:14
|
3 | let result = doccomments::add(2, 3);
| ^^^^^^^^^^^ use of undeclared crate or module `doccomments`
error: aborting due to previous error
For more information about this error, try `rustc --explain E0433`.
Couldn't compile the test.
failures:
src/lib.rs - add (line 11)
test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.21s
stderr:
Compiling playground v0.0.1 (/playground)
warning: function `main` is never used
--> src/lib.rs:1:4
|
1 | fn main() {
| ^^^^
|
= note: `#[warn(dead_code)]` on by default
warning: `playground` (lib) generated 1 warning
Finished test [unoptimized + debuginfo] target(s) in 0.66s
Running unittests src/lib.rs (target/debug/deps/playground-a7fbc171eada2644)
Doc-tests playground
error: doctest failed, to rerun pass `--doc`
In the Rust Playground, the crate generated is playground.
You can reference playground::<testname> in the doc comments.
///
/// ```
/// let result = playground::add(2, 3);
/// assert_eq!(result, 5);
/// ```
pub fn add(a: i32, b: i32) -> i32 {
a + b
}