Clippy lint · Suspicious · checked with Clippy 0.1.99

clippy::test_attr_in_doctest: unit tests in doctest are not executed

What it meansChecks for #[test] in doctests unless they are marked with either ignore, no_run or compile_fail. It is in the suspicious group and warns by default.

What you see

warning: unit tests in doctest are not executed
 --> main.rs:8:5
  |
8 | /// #[test]
  |     ^^^^^^^
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/stable/index.html#test_attr_in_doctest
  = note: `#[warn(clippy::test_attr_in_doctest)]` on by default

Real output of Clippy 0.1.99 (Rust 1.99) on the example below. Names and line numbers in yours will differ.

Does it matter?

Code in examples marked as #[test] will somewhat surprisingly not be run by cargo test. If you really want to show how to test stuff in an example, mark it no_run to make the intent clear.

Code that is most likely wrong or useless. Warns by default.

How to fix it

Clippy does not fix this one automatically. Change the code by hand:

Flagged

/// An example of a doctest with a `main()` function
///
/// # Examples
///
/// ```
/// #[test]
/// fn equality_works() {
///     assert_eq!(1_u8, 1);
/// }
/// ```
fn test_attr_in_doctest() {
    unimplemented!();
}

Turn it off, or on

Allow it where it does not fit your code, as narrowly as you can:

On one item

#[allow(clippy::test_attr_in_doctest)]
fn my_function() { /* ... */ }

Whole crate (Cargo.toml)

[lints.clippy]
test_attr_in_doctest = "allow"

One run

cargo clippy -- -A clippy::test-attr-in-doctest

The [lints] table needs Rust 1.74 or newer. In a workspace, put it under [workspace.lints.clippy] and add [lints] workspace = true to each member.

Suspiciousgroup

warndefault level

nofixed by cargo clippy --fix

1.76.0added in Rust

Clippy's own documentation

What it does

Checks for #[test] in doctests unless they are marked with either ignore, no_run or compile_fail.

Why is this bad?

Code in examples marked as #[test] will somewhat surprisingly not be run by cargo test. If you really want to show how to test stuff in an example, mark it no_run to make the intent clear.

Examples

/// An example of a doctest with a `main()` function
///
/// # Examples
///
/// ```
/// #[test]
/// fn equality_works() {
///     assert_eq!(1_u8, 1);
/// }
/// ```
fn test_attr_in_doctest() {
    unimplemented!();
}

From the Clippy lint list (0.1.99), part of the Rust project, MIT or Apache-2.0. Official entry.

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