Crate test_generator
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Overview
This crate provides #[test_resources] and #[bench_resources] procedural macro attributes
that generates multiple parametrized tests using one body with different resource input parameters.
A test is generated for each resource matching the specific resource location pattern.
Getting Started
First of all you have to add this dependency to your Cargo.toml:
[dev-dependencies]
test-generator = "^0.3"The test-functionality is supports stable Rust since version 1.30, whereas the bench-functionality requires an API from unstable nightly release.
#![cfg(test)]
extern crate test_generator;
// Don't forget that procedural macros are imported with `use` statement,
// for example importing the macro 'test_resources'
#![cfg(test)]
use test_generator::test_resources;Example usage test:
The test functionality supports the stable release of Rust-compiler since version 1.30.
#![cfg(test)]
extern crate test_generator;
use test_generator::test_resources;
#[test_resources("res/*/input.txt")]
fn verify_resource(resource: &str) {
assert!(std::path::Path::new(resource).exists());
}Output from cargo test for 3 test-input-files matching the pattern, for this example:
$ cargo test
running 3 tests
test tests::verify_resource_res_set1_input_txt ... ok
test tests::verify_resource_res_set2_input_txt ... ok
test tests::verify_resource_res_set3_input_txt ... ok
test result: ok. 3 passed; 0 failed; 0 ignored; 0 measured; 0 filtered outExample usage bench:
The bench functionality requires the nightly release of the Rust-compiler.
#![feature(test)] // nightly feature required for API test::Bencher
#[macro_use]
extern crate test_generator;
extern crate test; /* required for test::Bencher */
mod bench {
#[bench_resources("res/*/input.txt")]
fn measure_resource(b: &mut test::Bencher, resource: &str) {
let path = std::path::Path::new(resource);
b.iter(|| path.exists());
}
}Output from cargo +nightly bench for 3 bench-input-files matching the pattern, for this example:
running 3 tests
test bench::measure_resource_res_set1_input_txt ... bench: 2,492 ns/iter (+/- 4,027)
test bench::measure_resource_res_set2_input_txt ... bench: 2,345 ns/iter (+/- 2,167)
test bench::measure_resource_res_set3_input_txt ... bench: 2,269 ns/iter (+/- 1,527)
test result: ok. 0 passed; 0 failed; 0 ignored; 3 measured; 0 filtered outExample
The example demonstrates usage
and configuration of these macros, in combination with the crate
build-deps monitoring for any change of these resource files and conditional rebuild.
Internals
Let’s assume the following code and 3 files matching the pattern “res/*/input.txt”
#[test_resources("res/*/input.txt")]
fn verify_resource(resource: &str) { assert!(std::path::Path::new(resource).exists()); }the generated code for this input resource will look like
#[test]
#[allow(non_snake_case)]
fn verify_resource_res_set1_input_txt() { verify_resource("res/set1/input.txt".into()); }
#[test]
#[allow(non_snake_case)]
fn verify_resource_res_set2_input_txt() { verify_resource("res/set2/input.txt".into()); }
#[test]
#[allow(non_snake_case)]
fn verify_resource_res_set3_input_txt() { verify_resource("res/set3/input.txt".into()); }Note: The trailing into() method-call permits users to implement the Into-Trait for auto-conversations.