Testing

One line: Three kinds of test, one command, and no assertion library — cargo test runs the unit tests inside your modules, the integration tests in tests/, and every example in your documentation.

The test framework is part of the language rather than a dependency, which has one consequence worth noticing on day one: there is no vocabulary to learn. A test is a function that panics when it is unhappy, and assert_eq! is the whole API.

Lesson	Level	What it covers
What a test asserts	201	assert! vs assert_eq!, the message, floats, and the assertion that cannot fail
Where a test goes	201	Inside the module or outside the crate, and the #[should_panic] that passes on any panic
The example that is a test	201	Doc tests: an integration test that is also the documentation

The three, in one table

	Lives in	Sees	Good for
unit	#[cfg(test)] mod tests in src/	private items	the awkward internals
integration	a file directly in tests/	the public API	behaviour that survives a refactor
doc	a ``` block in ///	the public API	the one example a reader needs

Where the rest of it is

The harness itself, and running tests faster: cargo-nextest, one process per test. Testing a program rather than a library — arguments, exit status, stdout: Testing a command. And the attributes all of this is built out of — #[cfg], #[test], #[should_panic] — are in what an attribute is.

Where it goes next

A test that fails is a panic, and what a panic actually does is its own page. And the reason most of this library's examples need no tests at all is that every one of them has a recorded answer key CI re-checks — the same idea as a doc test, applied to a whole program.

Po polsku

W Ruscie nie dobiera się biblioteki do testów: mechanizm uruchamiający je (test harness) jest częścią języka, więc nie ma tu odpowiednika JUnita, pytesta ani osobnej biblioteki asercji do nauczenia się. Test to zwyczajna funkcja, która panikuje, kiedy coś się nie zgadza, a assert_eq! to w zasadzie całe API. Jedno polecenie cargo test uruchamia wszystkie trzy rodzaje naraz: testy jednostkowe w module #[cfg(test)] wewnątrz src/ (widzą elementy prywatne), testy integracyjne w katalogu tests/ (widzą wyłącznie publiczne API) oraz testy dokumentacyjne, czyli przykłady z komentarzy ///, które są przy okazji dokumentacją.

Szukaj po polsku: testy jednostkowe w Ruscie · testy integracyjne · rust cargo test · rust doc tests · rust cfg test mod tests