Development dependencies
Sometimes there is a need to have dependencies for tests (or examples,
or benchmarks) only. Such dependencies are added to Cargo.toml
in the
[dev-dependencies]
section. These dependencies are not propagated to other
packages which depend on this package.
One such example is using a crate that extends standard assert!
macros.
File Cargo.toml
:
# standard crate data is left out
[dev-dependencies]
pretty_assertions = "0.4.0"
File src/lib.rs
:
// externing crate for test-only use
#[cfg(test)]
#[macro_use]
extern crate pretty_assertions;
pub fn add(a: i32, b: i32) -> i32 {
a + b
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_add() {
assert_eq!(add(2, 3), 5);
}
}
See Also
Cargo docs on specifying dependencies.